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HomeMy WebLinkAboutECF_Early_Notice_Request_190213.pdf
February 11, 2019
Matt Herrera, AICP
City of Renton
Community & Economic Development
1055 South Grady Road
Renton, WA 98057
Re: Cedar River Apartments: SEPA – Request for Early Notice
The Watershed Company Reference Number: 170314
Dear Matt:
This letter relates to the Cedar River Apartments project and is intended to constitute a
formal ‘request for early notice’ pursuant to Renton Municipal Code 4-9-070.J.11. This
letter follows receipt of your email, dated February 1, 2019, in which you outlined three
specific items associated with the project/site that have the potential to result in
significant adverse impacts. Such a level of impacts, in one or more of the three
identified areas, would result in issuance of a SEPA Determination of Significant (DS).
Issuance of a DS would require the preparation and submittal of an Environmental
Impact Statement by the applicant. Pursuant to WAC 197-11-350(2), this letter intends to
provide additional clarification on each of the three identified areas of concern ahead of
the City’s threshold determination. Multiple exhibits are referenced below and can be
found at the end of the letter.
Transportation
Summary
A traffic impact report was prepared for the subject project (Traffic Impact Analysis for
Cedar River Apartments, November 1, 2018, by William Popp Associates [Popp Report])
(see Exhibit 1). The report analyzed traffic related impacts and provided several
mitigation recommendations. The Popp Report was based upon the proposal to
construct 481 apartment units and approximately 25,000 square feet of medial office
space.
Impacts
The Popp Report concluded that at project completion (year 2023/2034), the project is
estimated to generate approximately 3,500 average weekday (24 hour) vehicle trips with
Cedar River Apartments
SEPA: Request for Early Notice
February 11, 2019
Page 2
240 of those occurring in the AM peak hour and 300 occurring in the PM peak hour. The
average weekday 24-hour traffic volume on SR-169 between I-405 and Cedar River Park
Drive at project completion (year 2023/24) is estimated to be approximately 47,000
vehicles, with 3,000 vehicles occurring in the AM peak hour and 3,500 vehicles occurring
in the PM peak hour. The project’s estimated vehicular impact on this section of
roadway is approximately 6% for each peak hour, and 7% for the daily condition.
The Popp Report also analyzed level of service (LOS) impacts to intersections. LOS as
referenced here is the national grading system for traffic operations, with A being the
best, representing very little vehicle delay (< 10 seconds/vehicle), E being the point of
maximum throughput, but high level of delay (55 to 80 seconds/vehicle), and F
representing breakdown and extensive or intolerable delay (> 80 seconds/vehicle). LOS
D is considered by most agencies to be an acceptable future design condition (35 to 55
seconds/vehicle).
The intersection capacity analyses for 2023 indicate that all of the analyzed intersections
operate at LOS D or better, with the exception of the I-405/SR-169/Sunset Way
southbound on-ramp intersection, which is estimated to operate at LOS E. Both the I-405
north and southbound ramp intersections, however, can quickly deteriorate past LOS E
conditions as a result of ramp metering caused by severe congestion on I-405.
Proposed Mitigation Measures
As described in the Popp Report, the project will include frontage improvements, plus a
new direct access to SR-169. A total of approximately $2.2 million in traffic impact fees
are also to be paid. In addition to these site-specific mitigation measures, several nearby
projects are expected to result in traffic improvements. Specifically, WSDOT in
conjunction with the City of Renton have proposed improvement to the southbound I-
405 on-ramp and eastbound approach that would result in more efficient storage and
metering on the ramp than currently exists; thereby minimizing the queue (backup) on
SR-169, in particular for AM peak hour conditions. These efforts would improve
intersection level of service from LOS E to D during the morning peak hour by up to 20
seconds per vehicle, and improve the delay for the PM condition by up to 11 seconds per
vehicle. Under existing conditions, during the morning commute period, the westbound
traffic on SR-169 can queue back excessively (sometimes exceeding 4,000 ft) and longer
with a rolling queue.
Furthermore, the I-405 Renton to Bellevue Widening and Express Toll Lanes project and
the I-405/SR-167 Interchange Direct Connector Project, which are currently under
construction with completion in 2024, should significantly reduce congestion and
decrease travel time on I-405 in this area, which in theory would minimize excessive
ramp meter intervals at the I-405/SR-169/Sunset Way southbound on-ramp intersection
and at the I-405/SR-169 northbound on/off-Ramp intersection, in particular for AM
Cedar River Apartments
SEPA: Request for Early Notice
February 11, 2019
Page 3
commute period conditions. It is estimated that the I-405 Renton to Bellevue Widening
and Express Toll Lanes project would improve intersection level of service from LOS E
to D during the morning peak hour by up to 20 seconds per vehicle (for all movements),
and improve the delay for the PM condition by up to 11 seconds per vehicle (for all
movements). During the morning commute period, the westbound traffic on SR-169 can
queue back excessively sometimes exceeding 4,000 feet and longer with a rolling queue.
Conclusion
The proposed project will generate substantial new vehicular trips. These trips will
result in an additional load on the existing transportation infrastructure in the vicinity.
However, the applicant will install access/intersection improvements at the site and pay
in excess of $2 million in traffic impact fees. Therefore, proposed mitigation measures
are expected to significantly offset traffic impacts associated with the proposed project.
In addition, multiple regional improvements along the I-405/SR-167 corridor are
expected to improve congestion in the area. With implementation of all mitigation
measures, combined with planned regional improvements, no significant adverse
impacts are anticipated.
Groundwater Contamination
Summary
Due to the historical use of the site, including as home to the Stoneway Concrete Facility,
multiple contaminants have been detected at the site. As a result, a Voluntary Cleanup
Program (VCP) (see Exhibit 2) was prepared for the project site. The Washington
Department of Ecology (Ecology) responded to the VCP on July 19, 2018. Specifically,
Ecology issued several opinions, including:
• …upon completion of your proposed cleanup, no further remedial action will likely be
necessary to clean up contamination at the Site.
• The proposed future use of the Site (residential) does not meet the MTCA definition of an
industrial property; therefore, soil cleanup levels suitable for unrestricted land use are
appropriate.
• …cleanup levels… are considered appropriate for soil at the Site and are protective of
human health and the environment.
Specific to groundwater protection, pH was considered to be a water quality parameter
of concern for the site. Arsenic is an additional principal contaminant present within
groundwater at the site. In addition to the VCP, the applicant will be entering into an
Environmental Covenant (Covenant) with Ecology, intended to restrict certain activities
and uses of the Property to protect human health and the environment… The Covenant, a draft
copy of which is attached as Exhibit 3, includes specific prohibitions and requirements to
achieve this goal.
Cedar River Apartments
SEPA: Request for Early Notice
February 11, 2019
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Impacts
The Covenant states that the applicant shall: Not expose contaminated soil, result in a release
of contaminants, or create a new exposure pathway, without prior written approval of Ecology.
Thus, the Covenant will ensure that, only with Ecology approval, will any contaminated
soils be exposed. Specific to groundwater contamination, the Covenant outlines the goal
of containing contaminated groundwater beneath the Property. Contact with high pH
groundwater is to be prevented by placing clean inert fill material within the settling
ponds, as is proposed by the applicant. Further, pursuant to the Covenant, groundwater
is not to be extracted for any purpose other than investigation, monitoring, or remediation in
accordance with requirements imposed by Ecology… Any groundwater extracted from the
site would be considered potentially contaminated. However, pursuant to the VCP and
Covenant, monitoring wells are to be established along the western property boundary,
as this area is within approximately 800 feet of City of Renton water supply wells.
Finally, stormwater infiltration will not be allowed at the site, in an effort to minimize
the potential for mobilization of contaminants.
Proposed Mitigation Measures
To ensure that on-site contaminants are prevented from impacting human health and
the environment, the applicant will comply with the VCP and Covenant, including the
Groundwater Monitoring Plan and the Operation, and Maintenance and Contingency
Plan.
Conclusion
Prior uses at the site have resulted in contaminated soils. The site owner has worked
with Ecology to prepare a VCP that involves cleanup of the site. In addition, the
applicant has entered into a covenant with Ecology to ensure that contaminated soils are
not impacted and that monitoring is continued to ensure protection of the City’s nearby
water wells. Stormwater generated by the proposed project will be tight-lined to the
river, thereby minimizing the potential for mobilization of contaminants. Overall, the
proposed project will not result in additional impacts to the groundwater system; while
approved cleanup actions will ensure that occupants of the proposed uses will not be
negatively impacted.
Channel Migration Zone
Summary
As described in the Review of Shoreline Stabilization Alternatives for the Cedar River
Apartments Project, in Renton, WA, dated October 30, 2018 and prepared by Golder
Associates, Inc. (Golder Report) (see Exhibit 4), a majority of the project site is located
within the regulated severe channel migration zone. It is further identified as being
located within an unconstrained channel migration zone, as designated by King County
Water and Land Resources Division in the April 2015 Cedar River Channel Migration
Cedar River Apartments
SEPA: Request for Early Notice
February 11, 2019
Page 5
Study (KC Study) (see Exhibit 5). As described in the KC Study, the unconstrained
channel migration zone does not recognize artificial constraints and, therefore predicts
channel migration in the absence of levees, revetments, and infrastructure. The KC
Study thus mapped migration areas in recognition of certain artificial structures that can
restrain channel migration. These included all publicly maintained structures in the City
of Renton, as well as SR-169 and sole access roads. Areas located landward of these
structures were designated as ‘disconnected migration areas’ and were not formally
mapped as within the channel migration zone. As part of this designation, structures are
to be constructed to a height above the 100-year floodplain elevation.
However, as made clear in the KC Study, no privately maintained structures were
mapped as barriers to migration. This includes the existing concrete wall at the project
site that runs along the right bank of the river (see Figure 1). The wall is constructed of
two rows of vertically stacked ecology blocks with a reinforced vertical concrete wall
poured on top. Thus, no determination was made by King County as to the height of the
wall or whether or not the existing on-site wall would prevent migration of the river.
Rather, the channel migration zone was mapped as if the wall does not exist.
Figure 1. View of existing concrete wall – looking upstream.
Cedar River Apartments
SEPA: Request for Early Notice
February 11, 2019
Page 6
Based upon the KC Study, it is clear that existing structures can prevent migration of the
river. Because the KC Study specifically excluded private structures, however, the on-
site wall was not assessed by King County. While not explained, it can be assumed that
the KC Study purposefully omitted private structures due to access and budget
constraints. However, specific to the project site, the location, height, and effectiveness of
the wall should be considered. In the Golder Report, the existing wall is described as
corresponding with the 100-year flood inundation limits across the upstream and
downstream portions of the site. Only in the middle of the site, in the area around the
settling ponds, does the floodplain encroach beyond the wall and into the site. Thus, the
height of the wall, across a large portion of the site, is at or above the 100-year floodplain
elevation. The proposed plan for the site includes a lowering of a portion of the wall.
However, channel migrating processes often begin with scouring at the toe of
embankments.
The Cedar River is also constrained downstream and upstream of the site by maintained
civil infrastructure. The I-405 bridge lies approximately 720 feet downstream of the site,
and SR-169 lies within 135 feet of the river channel adjacent to the upstream end of the
site. Both of these are publicly maintained structures and considered to be barriers to
channel migration within the KC study, further constraining the plausibility of the
channel migrating within the vicinity.
Upon reviewing historical aerial photos from 1946, 1954, 1961, 1977, 1985, and 2002, no
signs of channel migration were observed along the project parcel. As described in the
Golder Report, the wall was likely not installed until sometime after 1977. If this channel
was prone to migrating inland towards the project site, there has been no sign of this
within the last 73 years, including at least several decades when no wall was present.
Impacts
While the site is nearly entirely encumbered by a mapped severe channel migration
zone, the existing wall does constrain the river and prevent channel migration. While
King County was unable to consider the on-site wall while mapping the channel
migration zone, it should be considered when reviewing and assessing project specific
details. That is, large scale mapping and analysis efforts are crucial for understanding
context and regulatory implications. However, SEPA is to consider site specific existing
conditions, as well. In this case, the wall is still functional, in its current condition.
If the severe channel migration zone was mapped according to onsite conditions and
considered the wall to be a channel migration barrier, most of the project site would not
be in the severe channel migration hazard zone, or even the moderate channel migration
hazard zone. The wall extends from the upstream end of the parcel to approximately 296
feet from the downstream, or western, property boundary. It is not until this point that
the property becomes vulnerable to channel migration. Despite a softening of the
Cedar River Apartments
SEPA: Request for Early Notice
February 11, 2019
Page 7
shoreline at this point, just downstream the shoreline is armored by a retaining wall on
the adjacent property until the river crosses under I-405. Therefore, it is reasonable to
assume the channel has little to no potential to migrate into the project site. Future
development activities within the shoreline buffer include removing a length of wall
along the downstream end of the project and lowering a section of the wall. The section
of the wall to be lowered is located waterward of the settling ponds. The wall will be cut
down to the 35-foot elevation. Despite part of the wall being lowered to below the 100-
year base flood elevation, the property is still protected at the most vulnerable part of
most stream banks, the toe. Toe scour is the initial erosive force behind most bank failure
and channel migration. Since the toe of the bank will still be protected by a wall standing
a few feet above base flow, the most significant channel forming force is not a concern.
As for impacts, typically, construction within a severe channel migration zone
constitutes a risk to the development. That is, migration of the channel could jeopardize
some or all of the development. In this case, however, despite the mapped migration
zone, the proposed retention of the concrete wall will constrain the river from migrating
into the site. Thus, provided the wall is maintained and properly functioning, no
significant impacts are expected.
Proposed Mitigation Measures
In order to ensure that the site is primarily protected from migration of the Cedar River,
the existing concrete wall along the right bank of the river will be maintained in its
existing condition. If any sign of scour or structural failure is observed, a plan will be
developed to limit the erosion, or make the repairs necessary to maintain the structural
integrity of the wall.
Conclusion
The project is mapped by King County as being located within the severe channel
migration zone. King County did not consider the existing concrete wall along the right
riverbank in mapping the channel migration zone. The wall effectively prevents the
river from migrating in this location. Provided the wall is maintained, as the applicant
intends to do, there is no risk of the river channel significantly migrating into the site.
Further, a plan will be developed if any sign of scouring or structural failure is observed.
Thus, under no scenario would channel migration ever threaten the proposed
development. Therefore, no significant adverse impact will occur.
Summary
None of the above discussed three items, individually or collectively, constitute a
significant adverse impact, as defined by WAC 197-11-794. Transportation impacts are
to be offset through payment of traffic impact fees. Regional transportation
improvements will also help to offset impacts. Groundwater contamination has been
Cedar River Apartments
SEPA: Request for Early Notice
February 11, 2019
Page 8
thoroughly evaluated as part of cleanup efforts with Ecology and no further impacts to
groundwater will occur as site runoff will not be allowed to infiltrate. In addition,
cleanup efforts will ensure that human health and the environment are protected,
ensuring the safety of future site occupants. Finally, impacts associated with the mapped
channel migration zone will be avoided provided the existing concrete wall is
maintained and that contingency plans are implemented if migration is detected.
Overall, proposed mitigation measures will substantially offset project impacts; thus, no
significant adverse impacts will occur.
Please note that this document shall constitute a supplement to the previously submitted
SEPA Checklist, pursuant to WAC 197-11-350(4).
Thank you for your attention to this matter. Please call if you have any questions or if
we can provide you with any additional information.
Sincerely,
Kenny Booth, AICP
Senior Planner / Principal
Exhibit 1
Traffic Impact Analysis for Cedar River Apartments, November 1, 2018,
William Popp Associates.
William Popp Associates Transportation Engineers/Planners
________________________________________________________________________
(425) 401-1030
(425) 401-2124
e-mail: info@wmpoppassoc.com
14-400 Building z Suite 206 z 14400 Bel-Red Road z Bellevue, WA 98007
TRAFFIC IMPACT ANALYSIS
for
Cedar River Apartments
Prepared for:
SRM Renton, LLC
720 6th Street South Ste. 200
Kirkland, WA 98033
Prepared by:
William Popp Associates
14-400 Building, Suite 206
14400 Bel-Red Rd
Bellevue, WA 98007
November 1, 2018
Traffic Impact Analysis Cedar River Apartments
Page i
T A B L E O F C O N T E N T S
INTRODUCTION.......................................................................................................................................1
A. EXISTING CONDITIONS...................................................................................................................4
Table 1 Three-plus Year Accident History a .............................................................................................8
Table 2 Accident Type History a ...............................................................................................................8
2. TRAFFIC VOLUMES ............................................................................................................................9
Table 3 Existing Peak Hour Volume Summary a ......................................................................................9
3. LEVEL-OF-SERVICE ..........................................................................................................................12
Table 4 Intersection Level-of-Service Criteria........................................................................................13
Table 5 Existing Intersection Level-of-Service (Year 2017)..................................................................13
Individual Intersection Results (per Synchro) ........................................................................................13
4. PLANNED AND PROGRAMMED IMPROVEMENTS................................................................................14
B. FUTURE CONDITIONS ....................................................................................................................16
1. BACKGROUND TRAFFIC VOLUMES ...................................................................................................16
2. PROJECT TRIP GENERATION .............................................................................................................17
Table 6 Project Trip Generation Estimates a ...........................................................................................18
3. TRIP DISTRIBUTION AND TRAFFIC ASSIGNMENT...............................................................................19
4. BACKGROUND TRAFFIC PLUS PROJECT TRAFFIC VOLUMES .............................................................19
5. LEVEL-OF-SERVICE (FUTURE YEAR PHASED PROJECT CONDITIONS)...............................................22
Table 7 Phase 1 Intersection Level-of-Service (Year 2021)...................................................................22
Individual Intersection Results (per Synchro) ........................................................................................22
Table 8 Phase 2 Intersection Level-of-Service (Year 2022)...................................................................25
Individual Intersection Results (per Synchro) ........................................................................................25
Table 9 Phase 3 Intersection Level-of-Service (Year 2023)...................................................................26
Individual Intersection Results (per Synchro) ........................................................................................26
6. PARKING ..........................................................................................................................................27
C. CONCLUSIONS..................................................................................................................................27
1. PROJECT DETAILS ............................................................................................................................27
2. ACCIDENTS ......................................................................................................................................28
3. PROJECT VEHICULAR IMPACT ..........................................................................................................28
4. LEVEL OF SERVICE ...........................................................................................................................28
5. SITE ACCESS ....................................................................................................................................29
6. PARKING ..........................................................................................................................................29
D. MITIGATION AND RECOMMENDATIONS ................................................................................29
1. FRONTAGE IMPROVEMENTS .............................................................................................................29
2. PRIMARY SITE ACCESS ....................................................................................................................29
3. SECONDARY SITE ACCESS................................................................................................................30
4. OFF-SITE PROGRAMMED MITIGATION IMPROVEMENTS ....................................................................31
5. TRAFFIC IMPACT FEE .......................................................................................................................33
Traffic Impact Analysis (11/01/18) Cedar River Apartments
William Popp Associates Page 1
INTRODUCTION
The following report was prepared to address the traffic related impacts of the proposed new
Cedar River Apartments project located in the City of Renton. This study evaluates the
project’s AM and PM peak hour (street peak) traffic impacts at the following intersections per
the pre-application meeting direction:
1. SR 169/Sunset Way/Bronson Way/I-405 Southbound On-Ramp
2. SR 169/I-405 Northbound On-Ramp
3. SR 169/Shari’s Driveway
4. SR 169/Cedar River Park Dr
The study follows the typical City of Renton traffic impact analysis guidelines for project
impacts. These are evaluated for three separate phases, with Phase 3 being the year of
estimated full occupancy.
Project Identification
The site is located at 1915 Maple Valley Highway (SR 169) in the City of Renton. The parcel
number is 1723059026, and the total area of the site is approximately 12.5 acres. The site is
currently vacant in terms of building structures, however, it is used as a storage area for heavy
construction machinery. Presently, there are two access points to the site including one to
Cedar River Park Drive and one to SR 169.
A project vicinity map is shown in Figure 1.
Traffic Impact Analysis (11/01/18) Cedar River Apartments
William Popp Associates Page 2
Figure 1: Vicinity Map (north is up)
The project site fronts to SR 169 to the east, the Cedar River to the south, and Cedar River
Park to the west. A parcel map locating the site is shown in Figure 2.
Figure 2: Site Parcel Map (north is up)
Traffic Impact Analysis (11/01/18) Cedar River Apartments
William Popp Associates Page 3
The proposed Cedar River Apartments site plan consists of three different buildings, to be
constructed in three separate phases. Each building and phase is discussed below:
Phase 1 – Building A will be constructed as Phase 1 and presumed occupied by 2021. This
building will consist of 238 apartment units, on 5 levels; along with 306 parking stalls in the
structure. In addition to the structure parking, there will be some surface parking on the north
side of the building. Building A will be located on the west end of the site and its proposed
access will be to both Cedar River Park Drive and to SR 169. The SR 169 access will replace
the existing driveway opening.
Phase 2 –Building B will be constructed as Phase 2. This building will be located at the east
side of the site and will consist of 243 apartment units, on 5 levels, plus 4,852 gsf of
commercial retail on the ground floor for public use. Phase 2 is presumed to be occupied by
2022. The retail space is currently undetermined. There will be 339 parking stalls in the
structure.
Phase 3 – This phase proposes a Medical Office type use on the commercial pad located in the
north corner of the parcel, identified in this report as Building C. Parking is currently
undetermined. Access is presumed to be to the internal roadway in front of Building B and
the driveway is anticipated to be opposite the garage entry to Building B. No additional
access points to public roadways are proposed with Phase 3.
The site plan is presented in Figure 3.
Figure 3: Site Plan (north is up)
Traffic Impact Analysis (11/01/18) Cedar River Apartments
William Popp Associates Page 4
A. EXISTING CONDITIONS
Roadways
Key roadways serving the site are discussed below.
SR 169 is a two-way east/west Principal Arterial that connects between I-405 to the west and
extends east all the way to Enumclaw. The roadway in the site vicinity is a 7-lane roadway
with three-lanes each direction and left turn pocket / center two-way left turn lane, along with
curb, gutter, and sidewalks on both sides. On-street parking is prohibited. Traffic control
includes signals at all major intersection. The posted speed limit is 35 mph in the vicinity of
the site.
Cedar River Park Dr is a two-way local access public/private street that provides project
access and connection to recreational elements including the Cedar River Park, Carco Theatre,
and the Henry Moses Aquatics Center. The roadway is identified as a public road for a
distance of approximately 300 feet southwest from the SR 169 intersection, at which point it
is a private roadway for access and circulation through the park. The public portion of the
road is approximately 40 feet wide with curb, gutter, and sidewalks on both sides. On-street
parking is not permitted. The public portion of the roadway is channelized with a three-lane
section, two lanes northbound towards the signal at SR 169 (left turn and right turn pockets),
one lane southbound (exiting away from SR 169). The speed limit is presumed to be 25 mph.
On the west side of I-405, nearby roadways include Bronson Way, Houser Way, Sunset Way,
the one-way couplet of S 3rd St and S 2nd St, the one-way couplet of N3rd St and N 4th St, and
N 3rd St east of I-405 (becoming N 4th St further east at top of the hill), are all identified as
Principal Arterials.
A map identifying the City’s arterial classification is shown in Figure 4.
Traffic Impact Analysis (11/01/18) Cedar River Apartments
William Popp Associates Page 5
Figure 4: City Arterial Classification Map (north is up)
Intersection Geometrics and Signal Operations
SR 169 runs in a diagonal direction in the project vicinity, however, for this analysis, it is
described as in an east-west direction with side streets in the north and south directions.
SR 169/Sunset Way/Bronson Way/I-405 Southbound On-Ramp is a signalized intersection
with split phasing for all directions plus some overlaps. The intersection channelization is as
follows:
• Southbound approach – a four lane approach including a one left turn lane, a shared
left/thru lane where the thru is restricted to HOV only, a shared thru/right turn lane,
and a right turn lane. The right turn lanes have a large radius turn along with large
raised island with exclusive signal control to Bronson Way. There is no pedestrian
crosswalk across the main approach or the right turn lanes.
Traffic Impact Analysis (11/01/18) Cedar River Apartments
William Popp Associates Page 6
• Eastbound approach – a four-lane approach including dual left turn lanes, a thru lane
and a shared thru/right lane with a large right turn island. There is no pedestrian
crosswalk across this approach.
• Westbound approach – a four-lane approach that includes a left turn pocket, two thru
lanes and a right turn lane. There is no pedestrian crosswalk across this approach.
• The signal operates with three phases. The southbound phase runs with a westbound
right turn overlap. The westbound phase runs exclusive with no overlaps. The
eastbound phase runs with the southbound right turn lane overlap.
• The south leg is the I-405 southbound on-ramp, a two-lane roadway leaving the
intersection. This ramp has one lane with ramp meter control as well as an HOV
bypass lane. The ramp meter is approximately 510 feet south from the intersection
crosswalk.
SR 169/I-405 Northbound On-Ramp is a signalized intersection with special operations. This
intersection is approximately 400 feet east from the SR 169/I-405 Southbound On-Ramp
intersection. The intersection channelization is as follows:
• Southbound approach – a single lane off-ramp from northbound I-405. The lane is
right turn only. There is a pedestrian crosswalk across this approach.
• Eastbound approach – a three-lane approach including one left turn pocket and two
thru lanes. The two thru lanes do not have signal control and thus run free.
• Westbound approach – a four-lane approach that includes three thru lanes and one
right turn lane. There is no pedestrian crosswalk across this approach.
• The north leg exit lane to I-405 is a single lane with ramp meter approximately 775
feet north from the crosswalk at the intersection.
SR 169/Shari’s Driveway is a signalized intersection serving the restaurant plus a Quality Inn.
This intersection is approximately 270 feet east from the SR 169/I-405 Northbound On-Ramp
intersection. The intersection channelization is as follows:
• Southbound approach – a single or possibly dual lane for right or left turns, however
there is no channelization on this leg, as it is a commercial driveway. The pedestrian
crossing of this approach is the sidewalk across the driveway.
• Eastbound approach – a four-lane approach that includes one left turn pocket, and
three thru lanes. There is a pedestrian crosswalk across this approach. U-turns are
signed as prohibited however there is a fair amount of u-turn traffic observed.
• Westbound approach – a four lane approach that includes three thru lanes and one
designated right turn lane that extends through this intersection to the northbound on-
ramp. There is no pedestrian crossing of the east leg.
SR 169/Cedar River Park Dr is a signalized intersection serving the Cedar River Park and
amenities. This intersection is approximately 700 feet east from the SR 169/Shari’s Driveway
intersection. The intersection channelization is as follows:
Traffic Impact Analysis (11/01/18) Cedar River Apartments
William Popp Associates Page 7
• Eastbound approach – a three-lane approach that includes two thru lanes and one
shared thru/right turn lane. There is no pedestrian crosswalk across this approach.
• Westbound approach – a four-lane approach that includes three thru lanes and one
designated left turn pocket that transitions from a center two-way left turn lane. The
turn pocket is 200 feet in length plus a 150-foot transition opening to the center two-
way left turn lane markings. There is a pedestrian crossing of the east leg.
• Northbound approach – a two lane approach that includes a left turn lane and a right
turn lane that extend back approximately 175 feet to where the proposed Cedar River
Apartments access will be (and where the current gravel yard driveway is now). There
is a pedestrian crossing of this approach.
Pedestrian Facilities
Pedestrian facilities in the vicinity of the site include sidewalks on the adjacent roadways.
Pedestrian access from the site to the west side of I-405 into downtown Renton can be walked
via the sidewalk along the south side of SR 169 and under I-405. Alternatively, pedestrians
can walk through Cedar River Park near the river and underneath I-405 to a pedestrian signal
and crosswalk across Houser Way N.
Transit Service
Transit service in the region is provided by the King County Department of Transportation
(Metro Transit). There are two routes that run along SR 169 in the vicinity of the site. These
are Routes 143 and 907.
Route 143 runs between Black Diamond and Downtown Seattle. Buses run during the AM
and PM commute hours only with bus headways approximately 20 minutes apart in the peak
direction. Route 907 is DART (dial a ride transit) and provides service between Black
Diamond and the Renton Transit Center. Service is generally provided between 9am and
4pm. The bus stop for both of these routes are on SR 169 just east of the Cedar River Park
Drive intersection, essentially adjacent to the site.
The walking distance to/from the Renton Transit Center is approximately 4,000 feet, which is
presumed to be along S 3rd St to Houser Way N and under I-405 and through Cedar River
Park.
Accident Data, last 3 (available) calendar years.
A summary of the three-plus year accident data at the analysis intersections was obtained from
WSDOT Headquarters Olympia. Data for the subject intersection was for the period of
January 1, 2014 through May 31, 2017 for the subject intersections. A summary of available
accident data is presented in Table 1.
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Table 1
Three-plus Year Accident History a
Number of Accidents by Year Accident
Intersection 2014 2015 2016 2017a Total Rate b
SR 169/Sunset Way/I-405 SB On-Ramp 2 4 4 0 10 0.16
SR 169/I-405 NB On & Off-Ramp 4 5 10 3 22 0.43
SR 169/Shari’s Driveway 8 8 10 2 28 0.71
SR 169/Cedar River Park Dr 8 2 3 1 14 0.36
a Data period is 1/1/14 through 5/31/17.
b Accidents per million entering vehicles (acc/mev). Entering vehicles based on 2017 PM peak hour data * 10.
As shown in Table 1, the accident rate ranges between 0.16 acc/mev and 0.71 acc/mev for the
four analysis intersections for the 3-plus year period. The accident rates noted suggest
adequate relatively safe operations at these intersections. The typical standard threshold is 1.0
accidents per million entering vehicles (acc/mev) at which time further evaluation would be
needed.
The most common type of accidents are rear-end, sideswipe and enter-at-angle type of
accidents. Table 2 identifies the number of occurrences by accident type at each of the four
intersections.
Table 2
Accident Type History a
SR 169/Sunset/ SR 169/I-405 SR 169/Shari’s SR 169/Cedar All
I-405 SB Ramps NB Ramps Driveway River Park Drive Intersections
Rear End 2 18% 15 52% 10 33% 14 67% 41 45%
Side Swipe 6 55% 7 24% 5 17% 5 24% 23 25%
Enter at Angle 1 9% 1 3% 6 20% 2 10% 10 11%
Left Turn 1 9% 3 10% 7 23% 0 0% 11 12%
Other 1 9% 3 10% 2 7% 0 0% 6 7%
11 29 30 21 91
a For the period between 1/1/14 and 5/31/17.
As shown in Table 2, the rear-end accident is the most prevalent type of accident at three of
the four intersections. The most prevalent accident type at the SR 169/Sunset Way/I-405 SB
on-ramp intersection is a sideswipe condition, which is most likely due to the large number of
dual turn lanes.
Overall, cumulative for all four intersections, the rear-end type of accident accounts for of
45% of the total accidents, with sideswipe accidents at 25%. In general, rear-end accidents
are most common at heavily congested signalized intersections where motorists are not
anticipating stop conditions during green light situations.
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2. Traffic Volumes
Existing AM and PM peak hour turning movement counts were collected at the four subject
intersections in mid June of 2017. Table 3 below identifies the peak hour volume for each
location.
Table 3
Existing Peak Hour Volume Summary a
Total Entering Volume
Intersection AM PK PM PK
SR 169/Sunset Way/Bronson Way/I-405 Southbound On-Ramp 4,347 5,126
SR 169/I-405 Northbound On & Off-Ramp 3,267 4,058
SR 169/Shari’s Driveway 2,803 3,157
SR 169/Cedar River Park Dr 2,717 3,144
Pk between SB Ramps between NB Ramps between Shari’s Dvwy
Hr Direction and NB Ramps and Shari's Dvwy and Cedar River Park Dr
AM WB 2,220 2,090 2,020
EB 370 680 660
PM WB 1,360 960 950
EB 1,670 2,270 2,120
a Traffic counts conducted in mid June 2017
As shown in Table 3, the intersection with the heaviest amount of traffic is the SR 169/Sunset
Way/Bronson Way/I-405 Southbound On-Ramp intersection. The PM entering volume at this
intersection is about 20% greater than the AM entering volume. In general for all four
intersections, the PM peak hour intersection volume is about 18% greater. This is very high
volume intersection.
The link volume by direction as shown in Table 3 is about 2,100 vehicles during the AM peak
hour in the westbound direction. This volume reflects a 79% directional volume westbound.
The total volume on average is 2,680 vehicles for the AM peak hour.
For the PM peak hour, the peak directional volume is on average 2,020 vehicles. This volume
reflects a 65% directional volume eastbound. The total volume on average is 3,110 vehicles
for the PM peak hour.
A summary of the existing 2017 AM and PM peak hour volumes at the analysis intersections
are presented in Figure 5a and 5b.
A 24-hour count was obtained from WSDOT historical records, albeit somewhat dated, that
shows the hourly volume for an average weekday in April of 2010 (average for Tue through
Friday). The volumes are shown in Figure 6 and are presented to show the peaking nature by
hour of day.
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Traffic Impact Analysis (11/01/18) Cedar River Apartments
William Popp Associates Page 12
Figure 6: SR 169 Hourly Volumes
As shown in Figure 6, the peak hour for the average weekday is during the 5:00 PM hour.
Also shown in this figure is the hourly fluctuation in volume by direction. The westbound
direction clearly peaks in the morning and the eastbound clearly peaks in the evening.
3. Level-of-Service
Level-of-service (LOS) is a term defined by transportation and traffic engineers as a
qualitative and quantitative measure of operational conditions within a traffic stream and the
perception of these conditions by motorists and/or passengers. There are several quantitative
indices utilized depending on the type of intersection control present. There are six levels-of-
service that are given letter designations from "A" to "F", with "A" being the best, or
minimum delay conditions, and "F" being the worst, with maximum delay or jammed
conditions. LOS "C" or "D" is generally considered acceptable for planning and design
purposes, while LOS "E" represents operating conditions at or near capacity with freedom to
maneuver being extremely difficult.
Level-of-service for the existing condition was calculated using Trafficware’s Synchro
software. This software replicates the analytical procedures specified in the Highway
Capacity Manual. The level of service criteria are shown in Table 4. Level-of-service for
signalized and non-signalized intersections is quantified in terms of vehicular delay. Delay,
measured in terms of time (seconds), also represents driver discomfort, frustration, excess fuel
consumption and lost travel time.
Traffic Impact Analysis (11/01/18) Cedar River Apartments
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Table 4
Intersection Level-of-Service Criteria
Level of Stopped Delay Per Vehicle1
Service Definition signalized non-signalized
A Little or no delay Less than 10.0 sec Less than 10.0 sec
B Short traffic delays 10.1 to 20 sec 10.1 to 15 sec
C Average traffic delays 20.1 to 35 sec 15.1 to 25 sec
D Long traffic delays 35.1 to 55 sec 25.1 to 35 sec
E Very long traffic delays 55.1 to 80 sec 35.1 to 50 sec
F Extreme delay Greater than 80 sec Greater than 50 sec
1 Delay; seconds per vehicle
Note that for signalized intersections, the delay presented represents the overall operation of
the intersection, whereas the delay presented for unsignalized intersections represents the
delay for the critical approach or movement. The results are presented in this manner since
the overall intersection delay at a non-signalized intersection is generally quite good because
the major through street maneuvers are not impeded and for the most part carry the majority of
the traffic. It is also important to note that the level of service results from the Synchro output
do not fully take into consideration the queue spill back from upstream or downstream-
signalized intersections and the additional congestion that may occur.
The existing level of service at the analysis intersections is presented in Table 5.
Table 5
Existing Intersection Level-of-Service (Year 2017)
Individual Intersection Results (per Synchro)
Intersection LOS a Delay a Comments
AM PEAK HOUR b
1 SR 169/Sunset Way/Bronson Way/I-405 SB On-Ramp D 47 ramp meter not included
2 SR 169/I-405 NB On & Off-Ramp c C 28 ramp meter not included
3 SR 169/Shari’s Café/Quality Inn Driveway A 3 tee intersection
4 SR 169/Cedar River Park Dr A 6 tee intersection
PM PEAK HOUR b
1 SR 169/Sunset Way/Bronson Way/I-405 SB On-Ramp E 56 ramp meter not included
2 SR 169/I-405 NB On & Off-Ramp B 12 ramp meter not included
3 SR 169/Shari’s Café/Quality Inn Driveway A 3 tee intersection
4 SR 169/Cedar River Park Dr A 4 tee intersection
a LOS and Delay are per Synchro v10, HCM 2010 except Int2. Delay values represented in seconds per vehicle, all intersections are
signalized.
b street peak hour: AM 7:00-8:00am, PM 4:45-5:45pm.
c Int2 (SR 169/I-405 NB Ramps) computed using HCM2000 due to fact HCM2010 cannot compute non-NEMA conditions.
Traffic Impact Analysis (11/01/18) Cedar River Apartments
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As shown in Table 5, as stand-alone intersections, each of these are estimated to operate at
satisfactory level of service except for the SR 169/Sunset Way intersection (Int1), which is
estimated to operate at LOS E during the PM peak hour.
It is important to note that the operations of these four intersections are all affected directly by
the operations of I-405 and the subsequent ramp metering conditions for Intersections 1 and 2.
Any significant ramp congestion due to long ramp meter intervals generally results in
spillback congestion through the intersections in this analysis.
4. Planned and Programmed Improvements
According to the city of Renton’s 2019-2024 Transportation Improvement Program, there are
four roadway project improvement projects in the vicinity of the project.
TIP 34 -- Maple Valley Highway Barriers (Traffic Operations and Safety Project).
This project includes two barriers vicinity of western edge of Riverview Park: One is to install
a concrete median barrier between east and westbound travel lanes of the SR 169 S-Curve
between the Riviera Apartments and S. 5th Street including associated roadway widening to
add the barrier. The second barrier improvement will remove the existing concrete barrier end
treatment located eastbound (east of the Riviera Apartments) and replace with 2 new concrete
barriers extending west.
TIP 36-- NE 3rd Street/NE 4th Street Corridor Improvements (Corridor Project)
This project involves a series of improvements in this corridor to improve traffic operations
such as rechannelization and traffic signal modifications, possible transit priority signal
treatments and queue jumps. This project will seek to meet pedestrian, transit and bicycle
needs.
TIP 24-- South 2nd Street Conversion Project (Corridor Project)
The South 2nd Street Conversion Project will be improving multimodal mobility in around
the downtown core by converting an existing 4–lane one-way roadway to a roadway with one
through-lane in each direction between Main Ave South and Rainier Ave South. This project
also includes pedestrian and bicycle facilities, traffic operations improvements, and transit
upgrades that will provide better traffic operation and circulation for all modes of
transportation. The improvements include a westbound bypass transit lane from just west of
Logan Ave S to just east of Lake Avenue. Transit facility upgrades include new Rapid Ride
stops and a transit queue jump at the new traffic signal at the Shattuck intersection.
TIP 41 -- South 3rd Street Conversion Project (Corridor Project)
The project provides pedestrian and bicyclists facilities and enhancements, traffic operation
and circulation improvements in Downtown. The improvements include adding raised
intersections with bulb outs, parklets, pedestrian plaza, lighting, street furniture, streetscape,
bicycle blvd, bike racks, signage, wayfinding and converting S 3rd St to two-way operations.
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TIP 28 -- Houser Way S/N Non Motorized Improvements (Non-Motorized Project)
This project would install a separated bike facility on the north side of Houser Way S/N,
between Mill Ave S. and Bronson Way N. Intersection crossings would be improved at Cedar
River Park Drive and Mill Ave S. The project will include planning and pavement overlay,
channelization, and intersection crossing improvements. For feasibility and constructability
issues, the roadway and pedestrian bridge sections would not be part of this project.
Another project not included in the Transportation Element but that is included in the City’s
Rate Study for Impact Fees (8/26/11), is Project #10 which consists of widening SR 169 from
the Cedar River Park Entrance to East City Limits – “widen existing 4-lane roadway (7 lanes
for a very limited distance) to provide additional lane in each direction; traffic operations
improvements at intersections.” The total project cost was estimated at $83,693,292 and the
amount eligible for impact fees was $59,204,163. This cost is part of the total fee basis of
$134,330,224 as used for the denominator in the calculations of trip fees.
WSDOT Improvements
There are several projects currently in design or long range proposed that would have
significant impact on traffic operations on I-405 in the vicinity of the proposed Cedar River
Apartments project. They are:
I-405/SR 169 Interchange Improvements
There are currently two interchange projects proposed at this location. The first involves a
proposed short-term enhancement with widening of the southbound on-ramp to include two
general purpose metered lanes and one HOV by-pass lane. As part of this, the westbound
approach would be modified (underneath I-405) to include two westbound turn lanes to the
southbound ramp. This would involve rechannelization of the inside through lane to a shared
thru plus left turn lane. This concept is expected to be completed in 2019 as its benefits to
current traffic operations are substantial..
The second project is along-range plan (currently unfunded part of I-405 Master Plan) and
includes a major change of both the SR 169 interchange and adjacent roadways that would
include new ramps at N 3rd St and a fly-over southbound to eastbound SR 169. The estimated
completion of this concept would be about 15 years out and will require significant legislative
action to fund these remaining portions of the Master Plan.
I-405 - Renton to Bellevue Widening and Express Toll Lanes
The project will add new lanes to create a two-lane express toll lane system between SR 167
in Renton and Northeast 6th Street in Bellevue. In general, the project will add one new tolled
lane in each direction. The existing HOV lane will be combined with this new lane to create a
dual express toll lane system. Since this project adds a lane of capacity each way the
beneficial impacts on mainline and interchange operations should be substantial.
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Project highlights
• Dual express toll lane system from SR 167 in Renton to Northeast Sixth Street in
Bellevue
• New southbound auxiliary lane in the I-90 to 112th Avenue Southeast vicinity
• Improvements at interchanges, including Northeast Park Drive and Northeast 44th
Street in Renton, and 112th Avenue Southeast and Coal Creek Parkway in Bellevue
• Construction of portions of the Eastside Rail Corridor regional trail, including a 2.5-
mile paved section and a new crossing over I-405 in downtown Bellevue at the site of
the former Wilburton rail bridge (in partnership with King County)
• New direct access ramp and inline transit station at NE 44th Street in Renton to help
support Bus Rapid Transit operations (in partnership with Sound Transit)
The project timeline is:
• Summer 2015: Funded by Connecting Washington for preliminary engineering, right
of way acquisition, and construction
• 2019: Start of construction
• 2024: Open to traffic
The longer term plans for the south end of I-405 Master Plan includes one additional general
purpose lane in each direction in this section of the roadway and other associated
improvements to interchanges, local roadways, noise walls and storm water management
facilities. This longer-term work is not currently funded for design or construction.
I-405 - SR 167 Interchange Direct Connector Project
WSDOT is currently constructing a new flyover ramp connecting the HOT lanes on SR 167 to
the carpool lanes on I-405 in Renton.
This highway-to-highway connection will address weaving issues associated with drivers
exiting the carpool or HOT lanes, merging onto I-405 or SR 167, and merging across traffic
again to the toll lanes. The immediate result should be improved operations for both general-
purpose lanes and carpool or express toll lanes. .
B. FUTURE CONDITIONS
1. Background Traffic Volumes
Background traffic volumes were estimated by factoring the existing traffic volumes by a
calculated historical traffic growth rate up to the project's horizon year. The project’s
estimated horizon year was assumed to be 2021 for Phase 1, 2022 for Phase 2, and 2023 for
Phase 3.
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Historical average annual daily traffic counts in the area of the project were obtained from
WSDOT sources for the period between 2008 and 2016. The count locations include
locations on SR 169 just east of I-405. A summary total for all roadway segments noted
above indicate that the historical annual growth rates are trending around 1.3%. Given the
state’s policy directive to limit future travel growth a simplified background growth rate of
1% was used to forecast future volumes for all movements.
No pipeline projects were identified by the City that would have a significant impact on this
analysis.
Background volume forecasts for Year 2021, 2022, and 2023 are all shown in Appendix A.
2. Project Trip Generation
The Cedar River Apartments would consist of 481 apartments in two separate buildings;
Building A and B, with 5 levels each building. The third building is proposed as a medical
office building with a gross floor area of 25,000 gsf approximately, identified as Building C.
The project is proposed to be constructed in three phases. Each phase is discussed below and
the trip generation estimate bases are all per the ITE Trip Generation 10th Edition manual.
Phase 1 will be Building A. This building will consist of 238 apartment units, on 5 levels;
along with 306 structure parking stalls. The best-fit land use is ITE Land Use Code 221,
Multifamily Housing (Mid-Rise). Mid-rise multi-family housing includes apartments,
townhouses, and condominiums located within the same building with at least three other
dwelling units and that have between three and 10 levels (floors).
Phase 2 will be Building B. This building will consist of 243 apartment units, on 5 levels,
plus 4,852 gsf of commercial retail on the ground floor. There will be 339 structure parking
stalls. For the small space of commercial retail public use, and due to the fact the space(s)
is/are currently undefined, this analysis assumes an evenly split mix of four different retail
type uses including: LUC 814 Variety Store, LUC 875 Department Store, LUC 876 Apparel
Store, and LUC 920 Copy/Print/Express Ship Store. For the resultant retail trip generation
estimate, it was also assumed that 50% of the total trips would be pass-by related.
Since for Phase 2 there is a mix of land uses, an estimate of internal trip capture was made for
all non-pass-by related trips using NCHRP 684 “Internal Trip Capture Estimation Tool”. The
results are shown in Table 6.
Phase 3 will be the future commercial pad, identified in this report as Building C. It is
intended to be a Medical Office type use. Therefore, trip generation rates are based on ITE
LUC 720, Medical Office. Similar to Phase 2, since there is a mix of land use types, the
internal trip capture tool (NCHRP 684) was used to estimate internal and external trips with
Phase 3.
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The site is currently occupied by construction trucks and trailers and other heavy equipment.
However, the trips currently generated at the site are likely incidental and are assumed as
insignificant and thus identified in this analysis for any trip credit against future project trips.
The trip generation estimates for the project by phase are presented in Table 6.
Table 6
Project Trip Generation Estimates a
PHASE and, AM Peak PM Peak
ITE Code and Land Use Size AWT Total In Out Total In Out
PHASE 1
LUC 221 b – Multi-Family House Mid-Rise (3 to 10 floors) – 238 units (Building A)
Rate 5.44 0.360 0.260 0.740 0.440 0.610 0.390
Vol 1,295 86 22 64 105 64 41
PHASE 2
LUC 221 b – Multi-Family House Mid-Rise (3 to 10 floors) – 243 units (Building B)
Rate 5.44 0.360 0.260 0.740 0.440 0.610 0.390
Vol 1,322 87 23 64 107 65 42
LUC 814,815,875,920 c – Retail Mix – 4,852 gsf commercial/retail
Rate 61.21 1.85 0.67 0.33 4.95 0.50 0.50
Vol 297 9 6 3 24 12 12
Retail Primary & Diverted (50%) 149 5 3 2 12 6 6
Phase 2 Subtotal 1,471 92 26 66 119 71 48
PHASE 1 and 2
Total Trips (internal & external) 2,766 178 48 130 224 135 89
Internal Trip Capture Estimate d 55 2 1 1 6 3 3
Total External Trips 2,710 176 47 129 218 132 86
PHASE 3
LUC 720 e – Medical-Dental Office Building – approximately 25,000 gsf (Building C)
Rate 34.8 2.780 0.780 0.220 3.460 0.280 0.720
Vol 870 70 55 15 87 24 63
PHASE 1, 2 and 3
Total Trips (internal & external) 3,636 248 103 145 311 159 152
Internal Trip Capture Estimate d 145 10 5 5 14 7 7
Total External Trips 3,490 238 98 140 297 152 145
a ITE Trip Generation 10th Edition
b Mid-rise multifamily housing includes apartments, townhouses, and condominiums located within the same building with at least three
other dwelling units and that have between three and 10 levels (floors)
c A department store is a free-standing facility that specializes in the sale of a wide range of products including apparel, footwear, home
products, bedding and linens, luggage, jewelry, and accessories.
d Multi-Use Trip Capture per NCHRP 684 Internal Trip Capture Estimation Tool (see Appendix B)
e A medical-dental office building is a facility that provides diagnoses and outpatient care on a routine basis but is unable t o provide
prolonged in-house medical and surgical care. One or more private physicians or dentists generally operate this type of facility.
As shown in Table 6, for Phase 1 the site is estimated to generate 1,295 average weekday
daily trips, 86 AM, and 105 PM peak hour trips.
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For Phase 2, including Phase 1, the site is estimated to generate 2,710 average weekday daily
trips, 176 AM, and 218 PM peak hour trips to the surrounding street system. These would be
the total external trips to and from the project and for the retail these would be the retail
primary and/or diverted trips. Pass-by trips would already be on the street.
For Phase 3, the site is estimated to generate 3,490 average weekday daily trips, 238 AM, and
297 PM peak hour trips to the surrounding street system (which includes Phase 1 and 2).
Again these would be the external vehicle trips to and from the project as well as the retail
non-pass-by trips.
3. Trip Distribution and Traffic Assignment
The project trip distribution patterns were based in general on traffic volumes for the
surrounding roadways plus knowledge of the surrounding areas with respect to employment
and socio-recreational types of attractions. For all of the land uses including the residential,
retail, and office elements of the project, the analysis assumed the following:
• 25% to I-405 north and 25% to I-405 south,
• 10% to S 2nd St and S 3rd St in downtown Renton,
• 10% to N 3rd St and N 4th St through North Renton and westerly locations,
• 5% to the North Renton via the Houser Way bypass,
• 10% to N 3rd St east to the Renton Highlands via N 3rd-N 4th St,
• 15% to SR 169 east towards Fairwood, Maple Valley, Black Diamond and places east.
The AM peak and the PM street peak hour trip distribution and assignment for the project for
all phases is presented in Figure 7a and 7b. For each individual phase, the project trip
assignment at each intersection is shown in Appendix A.
4. Background Traffic Plus Project Traffic Volumes
Future year AM and PM peak hour with-project traffic volumes were developed by adding
project trips to the background forecast traffic volumes.
For Phase 1, the AM and PM peak hour volumes include the background traffic growth
estimate from 2017 to 2021 as well as the Project Phase 1 traffic, which would all be
representative for Year 2021. Similarly for Phase 2, the horizon year estimate is Year 2022
and the AM and PM peak hour volumes include an additional year of background growth plus
Phase 2 project traffic. With Phase 2 there will be a small amount of trips that stay on site as
a result of the small retail uses on site (trip capture). And finally, for Phase 3, the horizon year
estimate is Year 2023 and would include another year of background growth plus Phase 3
traffic. Like Phase 2, there will be a small amount of trips that stay on site as a result of the
small retail and the medical office mix with the residential.
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All of the volumes by movement at each intersection as well as by Phase and per peak hour
are all shown in Appendix A.
The Year 2023 AM and PM peak hour with project volumes are shown in Figure 8a and 8b.
5. Level-of-Service (Future Year Phased Project Conditions)
Level-of-service for the 2021 with- and without-project conditions were calculated for the
subject analysis intersections plus the site access. The results of the analysis are presented in
Table 7. All of the future level of service calculations assume existing geometric and signal
operations conditions.
Table 7
Phase 1 Intersection Level-of-Service (Year 2021)
Individual Intersection Results (per Synchro)
Without Project With Project
Intersection LOS a Delay a LOS a Delay a Comments
AM PEAK HOUR b
1 SR 169/Sunset/Bronson/I-405 SB Ramps D 51 D 52 ramp meter not included
2 SR 169/I-405 NB Ramps B 33 C 32 ramp meter not included
3 SR 169/Shari's Driveway A 3 A 3 tee intersection
4 SR 169/Cedar River Park Drive A 6 A 7 tee intersection
5 SR 169/East Site Access n/a n/a A 9 left turn into site
B 11 right turn to SR 169
PM PEAK HOUR b
1 SR 169/Sunset/Bronson/I-405 SB Ramps E 65 E 65 ramp meter not included
2 SR 169/I-405 NB Ramps B 13 B 13 ramp meter not included
3 SR 169/Shari's Driveway A 3 A 4 tee intersection
4 SR 169/Cedar River Park Drive A 5 A 5 tee intersection
5 SR 169/East Site Access n/a n/a D 25 left turn into site
D 28 right turn to SR 169
a LOS and Delay are per Synchro v10, HCM 2010 except Int2. Delay values represented in seconds per vehicle, all intersections are
signalized.
b street peak hour: AM 7:00-8:00am, PM 4:45-5:45pm.
c Int2 (SR 169/I-405 NB Ramps) computed using HCM2000 due to fact HCM2010 cannot compute non-NEMA conditions.
As shown in Table 7, as stand-alone intersections, each of these are estimated to operate at
satisfactory level of service except for the SR 169/Sunset Way intersection (Int1), which is
estimated to operate at LOS E during the PM peak hour.
The project traffic with Phase 1 is not estimated to have a significant impact on any of the four
signalized intersections.
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Traffic Impact Analysis (11/01/18) Cedar River Apartments
William Popp Associates Page 25
As noted earlier, it is important to note that the operations of these four intersections are all
affected directly by the operations of I-405 and the subsequent ramp metering conditions for
Intersections 1 and 2. Any significant ramp congestion due to long ramp meter intervals
generally results in spillback congestion through the intersections in this analysis.
Level-of-service for the 2022 with project condition was calculated for the subject analysis
intersections plus the site access. The results of the analysis are presented in Table 8. All of
the future level of service calculations assume existing geometric and signal operations
conditions.
Table 8
Phase 2 Intersection Level-of-Service (Year 2022)
Individual Intersection Results (per Synchro)
With Project
Intersection LOS a Delay a Comments
AM PEAK HOUR b
1 SR 169/Sunset/Bronson/I-405 SB Ramps E 59 ramp meter not included
2 SR 169/I-405 NB Ramps C 34 ramp meter not included
3 SR 169/Shari's Driveway A 3 tee intersection
4 SR 169/Cedar River Park Drive A 10 tee intersection
5 SR 169/East Site Access A 9 left turn into site
B 11 right turn to SR 169
PM PEAK HOUR b
1 SR 169/Sunset/Bronson/I-405 SB Ramps E 72 ramp meter not included
2 SR 169/I-405 NB Ramps B 13 ramp meter not included
3 SR 169/Shari's Driveway A 3 tee intersection
4 SR 169/Cedar River Park Drive A 6 tee intersection
5 SR 169/East Site Access D 27 left turn into site
D 29 right turn to SR 169
a LOS and Delay are per Synchro v10, HCM 2010 except Int2. Delay values represented in seconds per vehicle, all intersections are
signalized.
b street peak hour: AM 7:00-8:00am, PM 4:45-5:45pm.
c Int2 (SR 169/I-405 NB Ramps) computed using HCM2000 due to fact HCM2010 cannot compute non-NEMA conditions.
As shown in Table 8, as stand-alone intersections, each of these are estimated to operate at
satisfactory level of service except for the SR 169/Sunset Way intersection (Int1), which is
estimated to operate at LOS E during both the AM and PM peak hour.
The level of service results shown in Table 8 above include one year of background growth
plus Phase 2 traffic. The delay changes do not increase significantly for the majority of
intersections. Intersection 1 for the AM and PM peak hour are both estimated to increase by
an average of 7 sec/veh with Phase 2 traffic and one year of background growth. For the AM
condition, the level changes from LOS D to E, the PM condition is estimated to remain at
LOS E.
Again, as noted earlier, it is important to note that the operations of these four intersections
are all affected directly by the operations of I-405 and the subsequent ramp metering
Traffic Impact Analysis (11/01/18) Cedar River Apartments
William Popp Associates Page 26
conditions for Intersections 1 and 2. Any significant ramp congestion due to long ramp meter
intervals generally results in spillback congestion through the intersections in this analysis.
Level-of-service for the 2023 with project condition was calculated for the subject analysis
intersections plus the site access. The results of the analysis are presented in Table 9. All of
the future level of service calculations assume existing geometric and signal operations
conditions.
Table 9
Phase 3 Intersection Level-of-Service (Year 2023)
Individual Intersection Results (per Synchro)
With Project
Intersection LOS a Delay a Comments
AM PEAK HOUR b
1 SR 169/Sunset/Bronson/I-405 SB Ramps E 60 ramp meter not included
2 SR 169/I-405 NB Ramps D 36 ramp meter not included
3 SR 169/Shari's Driveway A 3 tee intersection
4 SR 169/Cedar River Park Drive A 11 tee intersection
5 SR 169/East Site Access A 9 WBL
B 11 NBR
PM PEAK HOUR b
1 SR 169/Sunset/Bronson/I-405 SB Ramps E 75 ramp meter not included
2 SR 169/I-405 NB Ramps B 13 ramp meter not included
3 SR 169/Shari's Driveway A 3 tee intersection
4 SR 169/Cedar River Park Drive A 8 tee intersection
5 SR 169/East Site Access D 28 WBL
D 32 NBR
a LOS and Delay are per Synchro v10, HCM 2010 except Int2. Delay values represented in seconds per vehicle, all intersections are
signalized.
b street peak hour: AM 7:00-8:00am, PM 4:45-5:45pm.
c Int2 (SR 169/I-405 NB Ramps) computed using HCM2000 due to fact HCM2010 cannot compute non-NEMA conditions.
As shown in Table 9, as stand-alone intersections, each of these are estimated to operate at
satisfactory level of service except for the SR 169/Sunset Way intersection (Int1), which is
estimated to operate at LOS E during both the AM and PM peak hour.
The level of service results shown in Table 9 above include one year of background growth
plus Phase 3 traffic. The level of services changes do not increase significantly for the
majority of intersections. Intersection 1 for the PM peak hour is estimated to increase by an
average of 3 sec/veh with Phase 3 traffic and one year of background growth (1 sec/veh for the
AM peak hour). Both peak hour conditions are estimated to remain at LOS E for the Phase 3
condition up from Phase 2.
And to re-iterate, the operations of these four intersections are all affected directly by the
operations of I-405 and the subsequent ramp metering conditions for Intersections 1 and 2.
Traffic Impact Analysis (11/01/18) Cedar River Apartments
William Popp Associates Page 27
Any significant ramp congestion due to long ramp meter intervals generally results in
spillback congestion through the intersections in this analysis.
6. Parking
The project is proposing in total 645 parking stalls in Buildings A and B. There are 41 surface
parking stalls proposed north of Building A, and 14 stalls along the internal access road in
front of Building B. The parking requirement for Buildings A and B is a range between 634
and 700 stalls. Thus the parking proposed complies with City code.
A useful tool in estimating parking demand for residential multi-family development is the
King County Multi-Family Residential Parking Calculator. This program calculates
parking/unit rates for any parcel/area in the county. The model indicates that for the subject
site parcel based on the bedroom count and floor areas as noted in the site plan, and assuming
parking costs are included in rent (not a separate item), the model yields a parking per unit
rate of 1.02 vehicles/unit for Building A and 1.07 vehicles per unit for Building B. The peak
demand is estimated to occur between 10 pm and 5 am.
In total, the parking demand estimate for all of the residential is 503 vehicles for peak demand
conditions. Given the designed parking supply of 645 stalls in the two garages, it is concluded
that the parking supply should be adequate to meet estimated demand.
The parking supply has not yet been identified for Building C, but it is presumed it will meet
or exceed code requirements.
C. CONCLUSIONS
1. Project Details
The site is located at 1915 Maple Valley Highway (SR 169) in the City of Renton. The parcel
number is 1723059026, and the total area of the site is approximately 12.5 acres. The site is
currently vacant in terms of building structures, however, it is used as a storage area for heavy
construction machinery. Presently, there are two access points to the site including one to
Cedar River Park Drive and one two SR 169.
The proposed project consists of three different buildings, to be constructed in three separate
phases. Phase 1 – Building A will consist of 238 apartment units, on 5 levels, along with 306
structure parking stalls and presumed occupied by 2021. In addition to the structure parking,
there will be some surface parking on the north side of the building. Phase 2 –Building B will
consist of 243 apartment units, on 5 levels, along with 339 structure parking stalls, plus 4,852
gsf of commercial retail on the ground floor for public use, and presumed occupied by 2022.
Phase 3 – Building C (as identified in this study) will be a Medical Office type use on the
commercial pad located in the north corner of the parcel. Parking is currently undetermined.
Traffic Impact Analysis (11/01/18) Cedar River Apartments
William Popp Associates Page 28
Access is presumed to be to the internal roadway in front of Building B and the driveway is
anticipated to be opposite the garage entry to Building B. No additional access points to
public roadways are proposed with Phase 3.
2. Accidents
Based on accident records obtained from WSDOT, none of the four subject intersection have
an accident rate higher than 0.71 for the 3-plus year of data. The accident rates ranged
between 0.16 and 0.71 acc/mev. The typical standard threshold is 1.0 acc/mev. The accident
occurrence and rate suggests no unusual unsafe conditions.
Based on all the data at the four intersections, the rear-end type of accident is the most
common accident type with 45% of the total accidents, next with sideswipe type accidents at
25%. In general, rear-end accidents are most common at heavily congested signalized
intersections where motorists are not anticipating stop conditions during green light situations.
3. Project Vehicular Impact
In total for all phases, the project is estimated to generate 3,490 average weekday daily trips,
238 AM peak hour trips and 297 PM peak hour trips to the surrounding street network.
Phase 1 with 238 units is estimated to generate 1,295 average weekday daily trips, 86 AM,
and 105 PM peak hour trips.
Phase 2 with 243 units plus 4,852 gsf retail is estimated to generate 1,471 average weekday
daily trips, 92 AM, and 119 PM peak hour trips to the surrounding street system.
Phase 3 with 25,000 gsf of medical office space is estimated to generate 870 average weekday
daily trips, 70 AM, and 87 PM peak hour trips to the surrounding street system.
When added all together there is the assumption of some trip capture thus as a mixed use
development at full buildout the project is estimated to generate slightly less trips than if each
phase were a stand alone project.
4. Level of Service
The results of the level of service analyses indicate that all of the subject intersections operate
at LOS D or better, with the exception of the SR 169/Sunset Way/I-405 SB On-Ramp
intersection which is estimated to operate at LOS E for the AM or PM peak hour with or
without the project for future conditions.
Traffic Impact Analysis (11/01/18) Cedar River Apartments
William Popp Associates Page 29
5. Site Access
The project will have two access points, one to Cedar River Park Drive and one to SR 169.
This analysis assumes that the majority of the project traffic will access Cedar River Park
Drive which will have signalized access to SR 169. The project site access to SR 169 which
will be approximately 350 feet southeast from the SR 169/Cedar River Park Dr intersection is
presumed to be left-in, right-in, and right-out. No left turn out was assumed for this driveway
due to the expected difficulty in doing so during the peak hour periods.
6. Parking
The project’s peak parking demand for all of the residential in Phase 1 and 2 is estimated to be
503 vehicles. The peak demand would occur for the overnight period. The proposed parking
supply in the two garages in Phase 1 and 2 totals to 645 stalls. Thus, the parking supply as
proposed for the residential will exceed parking demand estimates and no parking spill over is
estimated to occur to surrounding areas, primarily no spill over into the Cedar River Park area.
Parking supply has not yet been identified for Building C, the medical office proposed use.
However, it is assumed that the parking supply will meet or exceed demand. Of course this
will be better identified as the plans develop for that building.
D. MITIGATION and RECOMMENDATIONS
Based on the foregoing traffic impact analysis for the Cedar River Apartments project, the
draft mitigation recommendations are suggested:
1. Frontage Improvements
The City requirement along SR 169 per the development standards and the pre-app meeting is
a 6” curb, 8’ planter, 8’ sidewalk and 2’ clear behind sidewalk to new property line. Currently
there is an 8’ sidewalk. The current site plan provides for an additional 8’ for the sidewalk
and landscaping plus 2’ from back of sidewalk to the new property line (and then there’s a 15’
setback required that is being provided).
2. Primary Site Access
The project’s primary access will be to/from Cedar River Park Drive. The existing
configuration currently consists of two lanes (left and right) from the site access to SR 169,
and one lane exiting from SR 169. With heavy congestion on I-405, it is estimated that there
could be spill back congestion on SR 169 passing through this intersection, which in turn may
result in congestion when exiting from Cedar River Park Dr to SR 169, primarily left turns to
SR 169. Excessive delay from Cedar River Park Dr may be a result.
Traffic Impact Analysis (11/01/18) Cedar River Apartments
William Popp Associates Page 30
One consideration would be widening the Cedar River Park Dr approach to include dual left
turn lanes (for increase storage and shorter green time for dissipation) and a right turn lane.
Additional right of way consideration should be made and potential further evaluation
conducted when Building C as part of Phase 3 is approached.
All of the WSDOT improvements discussed in Section A.4. should result in decreased
congestion and spill back on SR 169.
3. Secondary Site Access
The project is proposing a direct access to SR 169 as a secondary access in addition to the
access to Cedar River Park Drive. There is an existing driveway opening at the point where
the curb lane begins to taper back from 3 lanes to 2 lanes heading east. This existing driveway
is about 490 feet from the stop bar at the Cedar River Park Dr intersection.
There is a two-way left turn lane on SR 169 that begins approximately 350 feet southeast from
the stop bar at the Cedar River Park Dr intersection. This 350-foot section consists of a 200’
left turn pocket plus a 150-foot transition opening. The proposed driveway is recommended
to be no closer than at the beginning of the two-way left turn lane, which as noted is 350 feet
south east from the stop bar at Cedar River Park Dr intersection. This location
recommendation is shown in Figure 9.
Figure 9: East Site Access to SR 169
Traffic Impact Analysis (11/01/18) Cedar River Apartments
William Popp Associates Page 31
Given the heavy volumes on SR 169, it is recommended that the egress for this driveway be
restricted to right turn out only. Due to the fact there is a two-way left turn lane, it is possible
that left turn traffic queuing in the turn lane and turning into the site can be made without
impact on the mainline traffic heading west or impact on those vehicles turning left to Cedar
River Park Drive. In addition, this ingress access option from the east would reduce vehicle
impact for the left turn at Cedar River Park Dr and also keep from extending the green time
for the left turn phase.
4. Off-Site Programmed Mitigation Improvements
An important near term WSDOT programmed project is widening of the southbound on-ramp
to I-405 from SR 169. The widening would include adding an additional lane on the on-ramp
(from two lanes to three lanes), widening from one general purpose metered lane and one
HOV by-pass lane to two general purpose metered lanes and one HOV by-pass lane(see
Figure 10).
In turn the westbound approach (SR 169) would be modified to a left turn lane and a shared
left/through lane. And at the southbound approach (Sunset Boulevard), the HOV lane
designation would be removed from the shared left/through lane, and two general-purpose
lanes would access the southbound on-ramp. It is estimated that this proposal would improve
intersection level of service from LOS E to D during the morning peak by up to 20 seconds
per vehicle (for all movements), and improve the delay for the PM condition by up to 11
seconds per vehicle (for all movements). During the morning commute period, the westbound
traffic on SR 169 can queue back excessively (sometimes exceeding 4,000 ft) and longer with
a rolling queue. It should be noted that this recommended change would significantly reduce
the overall travel time for HOVs to access southbound 1-405 in light of any difference with
the existing HOV bypass.
The proposed channelization plan from WSDOT is shown in Figure 10. This figure shows
paths for two large trucks side-by-side turning left on to the ramp.
Traffic Impact Analysis (11/01/18) Cedar River Apartments
William Popp Associates Page 32
Figure 10: SR 169/Sunset Way/I-405 SB On-Ramp Improvements
The level of service results noted in this traffic study are footnoted to indicate these results
reflect stand-alone intersection conditions. Computerized traffic simulation runs indicate
significant spill back however much of that depends on the operations of I-405 and the ramp
metering. It is expected that the proposed improvement shown in Figure 10 would result in
more efficient storage and metering on the ramp than currently exists thereby minimizing the
queue spill back on SR 169.
Furthermore, the I-405 Renton to Bellevue Widening and Express Toll Lanes project and the
I-405 - SR 167 Interchange Direct Connector Project should significantly reduce congestion
and decrease travel time on I-405 in this area which in turn and in theory would minimize
excessive ramp meter intervals at the SR 169/Sunset Way/I-405 Southbound On-Ramp
intersection and at the SR 169/I-405 Northbound On/Off-Ramp intersection, in particular for
AM commute period conditions.
It is our understanding that Figure 10 southbound ramp widening and rechannelization of SR
169/Sunset Way/I-405 SB On-Ramp intersection ”has been moved to the head of the line for
construction” by WSDOT and is estimated to be constructed las early as late 2019. The
Cedar River Apartments project would benefit from this project. A lower cost immediate type
option that had been analyzed and advocated by the City before the WSDOT current
construction program had advanced is removal of the HOV bypass lane from the on-ramp.
This would involve restriping the southbound on-ramp to remove the HOV bypass lane and
provide two general-purpose metered lanes. In this location, the HOV bypass only provides
Traffic Impact Analysis (11/01/18) Cedar River Apartments
William Popp Associates Page 33
travel time savings once the carpool is on the ramp. Also there are no bus routes that use the
on-ramp. However, since WSDOT has advanced their ramp project to a likely late 2019
implementation, this lower cost project becomes unnecessary.
5. Traffic Impact Fee
The City of Renton’s currently adopted traffic impact fees for various land use types are based
on the City’s “Rate Study for Impact Fees for Transportation, Parks, and Fire Protection”,
dated August 26, 2011.
The City’s impact fee rate based on PM peak hour trips generated by new development is
$7,517.08 per PM peak hour Trip (source: Table 7 of the City’s Rate Study 8/26/11). The
estimated PM peak hour total trips generated to the surrounding street system by this
development are 297 PM peak hour trips with completion of all phases of this development3.
That would result in a traffic impact fee of $2,232,573. It is important to note that this project
is a mixed-use development with residential, retail, and medical office uses. Computation of
traffic impact fees based on stand-alone uses in this case would not be applicable due to the
fact it would not take into consideration of internal trip capture on site between uses.
William Popp Associates Transportation Engineers/Planners
________________________________________________________________________
(425) 401-1030
FAX (425) 401-2125
e-mail: info@wmpoppassoc.com
14-400 Building z Suite 206 z 14400 Bel-Red Road z Bellevue, WA 98007
TECHNICAL APPENDIX
for
Cedar River Apartments
November 1, 2018
CONTENTS:
APPENDIX A: AM AND PM PEAK HOUR TURNING MOVEMENT
VOLUMES AND FORECASTS
APPENDIX B: TRIP GENERATION INTERNAL CAPTURE
CALCULATIONS FOR AM AND PM PEAK HOUR
APPENDIX C: AM AND PM PEAK HOUR LEVEL OF SERVICE
CALCULATIONS
$33(1',;$$33(1',;$$33(1',;$$33(1',;$
AM AND PM PEAK HOUR TURNING MOVEMENT
VOLUMES AND FORECASTS
1 SR 169/Sunset/Bronson/I-405 SB RampsExisting 2021 2021 Phase 1 2021 2022 Phase 2 2022 2023 Phase 3 2023 All Dev2017 Future Background Project w/Project Future Project w/Project Future Project w/Project byAM PKGrowth aTraffic Trips AM PK Growth Trips AM PK Growth Trips AM PK 2023EBLT 1 199 8 207 0 207 2 0 209 2 0 211 0EBLT 2 196 395 8 204 411 0 204 411 2 0 206 415 2 0 208 419 0EBT 104 4 108 2 110 1 3 114 1 5 120 10EBRT 47 2 49 0 49 0 0 49 0 0 50 0 WBLT77531 806 16 822 8 16 847 8 2 857 34WBT 578 23 601 6 607 6 7 621 6 1 628 14WBRT89536 931 15 946 9 19 975 10 3 988 37 NBLT 0 00 00 000 000 0NBT 0 00 00 000 000 0NBRT 0 00 00 000 000 0 SBLT 1 187 8 195 5 200 2 7 209 2 13 224 25SBLT 2 74 261 3 77 272 6 83 283 1 5 89 297 1 10 100 323 21SBT HOV 358 15 373 0 373 4 0 376 4 0 380 0SBT 495 853 20 515 888 0 515 888 5 0 520 897 5 0 525 905 0SBRT 439 18 457 0 457 5 0 461 5 0 466 04347 177 4524 50 4574 46 57 4676 47 34 4757 1412.0% 1.1% 1.2% 0.7% 3.0%aBackground growth estimated based on SR 169 count records WSDOTbProject: 238 apts (Ph1), 243 apts and 4.852 kgsf retail (Ph2), 25 kgsf medical office (Ph3)1SR 169/Sunset/Bronson/I-405 SB Ramps1SR 169/Sunset/Bronson/I-405 SB RampsExisting 2021 2021 Phase 1 w/Project 2022 Phase 2 2022 2023 Phase 3 2023 All Dev2017 Future Background Project 2021 Future Project w/Project Future Project w/Project byPM PKGrowth aTraffic Trips PM PK Growth Trips PM PK Growth Trips PM PK 2023EBLT 1 314 13 327 0 327 3 0 330 3 0 333 0EBLT 2 359 673 15 374 700 0 374 700 4 0 377 707 4 0 381 714 0EBT 520 21 541 6 547 5 7 560 6 2 567 15EBRT 65 3 68 0 68 1 0 68 1 0 69 0 WBLT 334 14 348 10 358 4 11 372 4 11 387 32WBT 236 10 246 4 250 2 4 256 3 6 265 14WBRT 770 31 801 10 811 8 10 829 8 15 853 35 NBLT 0 00 00 000 000 0NBT 0 00 00 000 000 0NBRT 0 00 00 000 000 0 SBLT 1 718 29 747 16 763 8 18 789 8 6 803 40SBLT 2 427 1145 17 444 1191 15 459 1222 5 16 480 1269 5 3 488 1290 34SBT HOV 202 8 210 0 210 2 0 212 2 0 214 0SBT 543 745 22 565 775 0 565 775 6 0 571 783 6 0 576 791 0SBRT 638 26 664 0 664 7 0 671 7 0 677 05126 208 5334 61 5395 54 66 5515 55 43 5613 1702.0% 1.1% 1.2% 0.8% 3.0%aBackground growth estimated based on SR 169 count records WSDOTbProject: 238 apts (Ph1), 243 apts and 4.852 kgsf retail (Ph2), 25 kgsf medical office (Ph3)
2 SR 169/I-405 NB RampsExisting 2021 2021 Phase 1 2021 2022 Phase 2 2022 2023 Phase 3 2023 All Dev2017 Future Background Project w/Project Future Project w/Project Future Project w/Project byAM PKGrowth aTraffic Trips AM PK Growth Trips AM PK Growth Trips AM PK 2023EBLT 171180180 0180 018 0EBT 348 14 362 13 375 4 15 394 4 28 426 56EBRT 00000000000 0 WBLT 00000000000 0WBT 1706 69 1775 37 1812 18 42 1872 19 6 1897 85WBRT 412 17 429 16 445 4 16 465 5 2 472 34 NBLT 00000000000 0NBT 00000000000 0NBRT 289 12 301 6 307 3 6 316 3 10 329 22 SBLT 00000000000 0SBT 00000000000 0SBRT 495 20 515 0 515 5 0 520 5 0 525 03267 133 3400 72 3472 35 79 3585 36 46 3667 1972.0% 2.1% 2.2% 1.3% 5.4%aBackground growth estimated based on SR 169 count records WSDOTbProject: 238 apts (Ph1), 243 apts and 4.852 kgsf retail (Ph2), 25 kgsf medical office (Ph3)2 SR 169/I-405 NB RampsExisting 2021 2021 Phase 1 w/Project 2022 Phase 2 2022 2023 Phase 3 2023 All Dev2017 Future Background Project 2021 Future Project w/Project Future Project w/Project byPM PKGrowth aTraffic Trips PM PK Growth Trips PM PK Growth Trips PM PK 2023EBLT 612630631 0641 065 0EBT 1604 65 1669 37 1706 17 41 1764 18 11 1793 89EBRT 00000000000 0 WBLT 00000000000 0WBT 704 29 733 24 757 8 25 789 8 32 829 81WBRT 246 10 256 10 266 3 11 280 3 11 293 32 NBLT 00000000000 0NBT 00000000000 0NBRT 771 31 802 16 818 8 17 843 8 4 856 37 SBLT 00000000000 0SBT 00000000000 0SBRT 672 27 699 0 699 7 0 706 7 0 713 04058 165 4223 87 4310 43 94 4447 44 58 4550 2392.0% 2.0% 2.1% 1.3% 5.3%aBackground growth estimated based on SR 169 count records WSDOTbProject: 238 apts (Ph1), 243 apts and 4.852 kgsf retail (Ph2), 25 kgsf medical office (Ph3)
3 SR 169/Shari's DrivewayExisting 2021 2021 Phase 1 2021 2022 Phase 2 2022 2023 Phase 3 2023 All Dev2017 Future Background Project w/Project Future Project w/Project Future Project w/Project byAM PKGrowth aTraffic Trips AM PK Growth Trips Traffic Growth Trips AM PK 2023EBUT 55 2 57 0 57 1 0 58 1 0 58 0EBLT 35 1 36 0 36 0 0 37 0 0 37 0EBT 1 240 10 250 0 250 2 0 252 3 0 255 0EBT 2 260 640 11 271 666 13 284 685 3 15 301 713 3 28 332 758 56EBT 3 140 6 146 6 152 2 6 159 2 10 171 22EBRT 0 00 00 000 000 0 WBLT 0 00 00 000 000 0WBT 1 546 22 569 16 585 6 16 606 6 2 614 34WBT 2 541 2008 22 563 2090 6 569 2143 6 7 581 2222 6 1 588 2252 14WBT 3 541 22 563 15 578 6 19 603 6 3 612 37WBT 4 380 15 395 16 411 4 16 432 4 2 438 34WBRT 7 07 07 007 007 0 NBLT 0 00 00 000 000 0NBT 0 00 00 000 000 0NBRT 0 00 00 000 000 0 SBLT 3 03 03 003 003 0SBT 0 00 00 000 000 0SBRT 55 2 57 0 57 1 0 58 1 0 58 02803 114 2917 72 2989 30 79 3098 31 46 3175 1972.0% 2.4% 2.6% 1.4% 6.2%aBackground growth estimated based on SR 169 count records WSDOTbProject: 238 apts (Ph1), 243 apts and 4.852 kgsf retail (Ph2), 25 kgsf medical office (Ph3)3 SR 169/Shari's DrivewayExisting 2021 2021 Phase 1 2021 2022 Phase 2 2022 2023 Phase 3 2023 All Dev2017 Future Background Project w/Project Future Project w/Project Future Project w/Project byPM PKGrowth aTraffic Trips PM PK Growth Trips Traffic Growth Trips PM PK 2023EBUT 15 1 16 0 16 0 0 16 0 0 16 0EBLT 41 2 43 0 43 0 0 43 0 0 44 0EBT 1 990 40 1030 0 1030 10 0 1040 10 0 1051 0EBT 2 778 2118 32 810 2204 38 848 2258 8 41 897 2339 9 11 917 2377 90EBT 3 350 14 364 16 380 4 17 401 4 4 409 37EBRT 0 00 00 000 000 0 WBLT 0 00 00 000 000 0WBT 1 355 14 369 10 379 4 11 394 4 11 409 32WBT 2 158 935 6 165 973 7 172 1007 2 4 177 1053 2 6 185 1107 17WBT 3 158 6 165 7 172 2 10 183 2 15 200 32WBT 4 264 11 275 10 285 3 11 299 3 11 313 32WBRT 13 1 14 0 14 0 0 14 0 0 14 0 NBLT 0 00 00 000 000 0NBT 0 00 00 000 000 0NBRT 0 00 00 000 000 0 SBLT 4 04 04 004 004 0SBT 0 00 00 000 000 0SBRT 31 1 32 0 32 0 0 33 0 0 33 03157 128 3285 88 3373 34 94 3501 35 58 3594 2402.0% 2.6% 2.7% 1.6% 6.7%aBackground growth estimated based on SR 169 count records WSDOTbProject: 238 apts (Ph1), 243 apts and 4.852 kgsf retail (Ph2), 25 kgsf medical office (Ph3)
4 SR 169/Cedar River Park DriveExisting 2021 2021 Phase 1 2021 2022 Phase 2 2022 2023 Phase 3 2023 All Dev2017 Future Background Project w/Project Future Project w/Project Future Project w/Project byAM PKGrowth aTraffic Trips AM PK Growth Trips Traffic Growth Trips AM PK 2023EBLT 0 00 00 000 000 0EBT 1 272 11 283 0 283 3 0 286 3 0 289 0EBT 2 296 623 12 308 648 0 308 648 3 0 311 660 3 0 314 682 0EBT 3 55 2 57 0 57 1 5 63 1 16 79 21EBRT 61 2 63 19 82 1 16 99 1 23 123 58 WBLT 12 0 12 0 12 0 0 13 0 3 16 3WBT 1 536 22 558 0 558 6 0 563 6 0 569 0WBT 2 783 1984 32 815 2065 0 815 2065 8 0 823 2085 8 0 831 2106 0WBT 3 665 27 692 0 692 7 0 699 7 0 706 0WBRT 0 00 00 000 000 0 NBLT 31 1 32 54 86 1 55 142 1 9 153 118NBT 0 00 00 000 000 0NBRT 6 06 06 006 017 1 SBLT 0 00 00 000 000 0SBT 0 00 00 000 000 0SBRT 0 0 0 0 0 0 0 0 0 0 0 02717 110 2827 73 2900 29 76 3005 30 52 3087 2012.0% 2.5% 2.5% 1.7% 6.5%aBackground growth estimated based on SR 169 count records WSDOTbProject: 238 apts (Ph1), 243 apts and 4.852 kgsf retail (Ph2), 25 kgsf medical office (Ph3)4 SR 169/Cedar River Park DriveExisting 2021 2021 Phase 1 2021 2022 Phase 2 2022 2023 Phase 2 2023 All Dev2017 Future Background Project w/Project Future Project w/Project Future Project w/Project byPM PKGrowth aTraffic Trips PM PK Growth Trips Traffic Growth Trips PM PK 2023EBLT 0 00 00 000 000 0EBT 1 1013 41 1054 0 1054 11 0 1065 11 0 1075 0EBT 2 989 2082 40 1029 2167 0 1029 2167 10 0 1039 2196 10 0 1050 2224 0EBT 3 80 383 083 1 892 1 699 14EBRT 36 1 37 54 91 1 50 142 1 9 153 113 WBLT 12 0 12 5 17 0 5 23 0 1 24 11WBT 1 342 14 356 0 356 4 0 359 4 0 363 0WBT 2 229 910 9 238 947 0 238 947 2 0 241 956 2 0 243 966 0WBT 3 339 14 353 0 353 4 0 356 4 0 360 0WBRT 0 00 00 000 000 0 NBLT 38 2 40 35 75 1 37 112 1 44 157 116NBT 0 00 00 000 000 0NBRT 66 3 69 0 69 1 0 69 1 3 73 3 SBLT 0 00 00 000 000 0SBT 0 00 00 000 000 0SBRT 0 0 0 0 0 0 0 0 0 0 0 03144 128 3272 943366 34 100 3499 35 63 3597 2572.8% 2.9% 1.8% 7.1%aBackground growth estimated based on SR 169 count records WSDOTbProject: 238 apts (Ph1), 243 apts and 4.852 kgsf retail (Ph2), 25 kgsf medical office (Ph3)
5 SR 169/Cedar River Apts East DrivewayExisting 2021 2021 Phase 1 2021 2022 Phase 2 2022 2023 Phase 3 2023 All Dev2017 Future Background Project w/Project Future Project w/Project Future Project w/Project byAM PKGrowth aTraffic Trips AM PK Growth Trips Traffic Growth Trips Growth 2020EBLT 00000000000 0EBT 629 26 655 0 655 7 0 661 7 1 669 1EBRT 0000005501621 21 WBLT 0003305801018 18WBT 1996 81 2077 0 2077 21 5 2103 21 3 2127 8WBRT 00000000000 0 NBLT 00000000000 0NBT 00000000000 0NBRT 0 0 01010010200 222 22 SBLT 00000000000 0SBT 00000000000 0SBRT 00000000000 02625 107 2732 13 2745 27 25 2797 28 32 2857 702.0% 0.5% 0.9% 1.1% 2.5%aBackground growth estimated based on SR 169 count records WSDOTbProject: 238 apts (Ph1), 243 apts and 4.852 kgsf retail (Ph2), 25 kgsf medical office (Ph3)5 SR 169/Cedar River Apts East DrivewayExisting 2021 2021 Phase 1 w/Project 2022 Phase 2 2022 2023 Phase 3 2023 All Dev2017 Future Background Project 2021 Future Project w/Project Future Project w/Project byPM PKGrowth aTraffic Trips PM PK Growth Trips Traffic Growth Trips Growth 2020EBLT 00000000000 0EBT 2148 87 2235 0 2235 22 0 2258 23 3 2283 3EBRT 000000880614 14 WBLT 0005505100414 14WBT 922 37 959 5 964 10 5 979 10 1 990 11WBRT 00000000000 0 NBLT 00000000000 0NBT 00000000000 0NBRT 00066071301225 25 SBLT 00000000000 0SBT 00000000000 0SBRT 00000000000 03070 125 3195 16 3211 32 25 3268 33 26 3326 672.0% 0.5% 0.8% 0.8% 2.0%aBackground growth estimated based on SR 169 count records WSDOTbProject: 238 apts (Ph1), 243 apts and 4.852 kgsf retail (Ph2), 25 kgsf medical office (Ph3)
$33(1',;%$33(1',;%$33(1',;%$33(1',;%
TRIP GENERATION INTERNAL CAPTURE
CALCULATIONS FOR AM AND PM PEAK HOUR
APPENDIX B (page1)
Project Name: Organization:
Project Location: Performed By:
Scenario Description:Date:
Analysis Year: Checked By:
Analysis Period:Date:
ITE LUCs1 Quantity Units Total Entering Exiting
Office 0 - GFA 0 0 0
Retail 815,920 4,852 GFA 5 3 2
Restaurant 930,936 - GFA 0 0 0
Cinema/Entertainment 000
Residential 221 481 DU 173 45 128
Hotel 0
All Other Land Uses2 0
178 48 130
Veh. Occ.4 % Transit % Non-Motorized Veh. Occ.4 % Transit % Non-Motorized
Office
Retail
Restaurant
Cinema/Entertainment
Residential
Hotel
All Other Land Uses2
Office Retail Restaurant Residential Hotel
Office
Retail
Restaurant
Cinema/Entertainment
Residential
Hotel
Office Retail Restaurant Residential Hotel
Office 0 0 0 0
Retail 0 0 0 0
Restaurant 0 0 0 0
Cinema/Entertainment 0 0 0 0 0
Residential 0 1 0 0
Hotel 0 0 0 0
Total Entering Exiting Land Use Entering Trips Exiting Trips
All Person-Trips 178 48 130 Office N/A N/A
Internal Capture Percentage 1% 2% 1% Retail 33% 0%
Restaurant N/A N/A
External Vehicle-Trips5 176 47 129 Cinema/Entertainment N/A N/A
External Transit-Trips6 0 0 0 Residential 0% 1%
External Non-Motorized Trips6 0 0 0 Hotel N/A N/A
1915 Maple Valley Highway, Renton
AM Street Peak Hour
William Popp Associates
Bill Popp Jr.
At Full Occupancy
24-Oct-18Phase A & B
Estimation Tool Developed by the Texas A&M Transportation Institute - Version 2013.1
Table 5-A: Computations Summary Table 6-A: Internal Trip Capture Percentages by Land Use
2Total estimate for all other land uses at mixed-use development site is not subject to internal trip capture computations in this estimator.
5Vehicle-trips computed using the mode split and vehicle occupancy values provided in Table 2-A.
1Land Use Codes (LUCs) from Trip Generation Manual , published by the Institute of Transportation Engineers.
6Person-Trips
*Indicates computation that has been rounded to the nearest whole number.
3Enter trips assuming no transit or non-motorized trips (as assumed in ITE Trip Generation Manual ).
4Enter vehicle occupancy assumed in Table 1-A vehicle trips. If vehicle occupancy changes for proposed mixed-use project, manual adjustments must be made
to Tables 5-A, 9-A (O and D). Enter transit, non-motorized percentages that will result with proposed mixed-use project complete.
Table 2-A: Mode Split and Vehicle Occupancy Estimates
Table 4-A: Internal Person-Trip Origin-Destination Matrix*
Destination (To)Origin (From)
Origin (From)Destination (To)
Cinema/Entertainment
Land Use Entering Trips Exiting Trips
Table 3-A: Average Land Use Interchange Distances (Feet Walking Distance)
NCHRP 684 Internal Trip Capture Estimation Tool
Table 1-A: Base Vehicle-Trip Generation Estimates (Single-Use Site Estimate)
0
0
Cinema/Entertainment
Development Data (For Information Only )
0
0
0
Estimated Vehicle-Trips3
Land Use
Cedar River Apartments
NCHRP Report 684 estimator PHASE 2.xlsx, Page 1-A
10/31/2018
APPENDIX B (page 2)
Project Name:
Analysis Period:
Veh. Occ. Vehicle-Trips Person-Trips* Veh. Occ. Vehicle-Trips Person-Trips*
Office 1.00 0 0 1.00 0 0
Retail 1.00 3 3 1.00 1.5 2
Restaurant 1.00 0 0 1.00 0 0
Cinema/Entertainment 1.00 0 0 1.00 0 0
Residential 1.00 45 45 1.00 128 128
Hotel 1.00 0 0 1.00 0 0
Office Retail Restaurant Residential Hotel
Office 0 0 0 0
Retail 1 0 0 0
Restaurant 0 0 0 0
Cinema/Entertainment 0 0 0 0 0
Residential 3 1 26 0
Hotel 0 0 0 0
Office Retail Restaurant Residential Hotel
Office 1 0 0 0
Retail 0 0 1 0
Restaurant 0 0 2 0
Cinema/Entertainment 0 0 0 0 0
Residential 0 1 0 0
Hotel 0 0 0 0
Internal External Total Vehicles1 Transit2 Non-Motorized2
Office 0 0 0 0 0 0
Retail 1 2 3 2 0 0
Restaurant 0 0 0 0 0 0
Cinema/Entertainment 0 0 0 0 0 0
Residential 0 45 45 45 0 0
Hotel 0 0 0 0 0 0
All Other Land Uses3 00 0 0 0 0
Internal External Total Vehicles1 Transit2 Non-Motorized2
Office 0 0 0 0 0 0
Retail 0 2 2 2 0 0
Restaurant 0 0 0 0 0 0
Cinema/Entertainment 0 0 0 0 0 0
Residential 1 127 128 127 0 0
Hotel 0 0 0 0 0 0
All Other Land Uses3 00 0 0 0 0
Land Use
Table 7-A (D): Entering Trips
2Person-Trips
Person-Trip Estimates
Cedar River Apartments
AM Street Peak Hour
Table 9-A (D): Internal and External Trips Summary (Entering Trips)
Table 8-A (O): Internal Person-Trip Origin-Destination Matrix (Computed at Origin)
Origin (From)
Destination (To)
Cinema/Entertainment
Table 7-A: Conversion of Vehicle-Trip Ends to Person-Trip Ends
Table 7-A (O): Exiting Trips
0
0
0
Table 8-A (D): Internal Person-Trip Origin-Destination Matrix (Computed at Destination)
Origin (From)
Origin Land Use Person-Trip Estimates External Trips by Mode*
External Trips by Mode*
1Vehicle-trips computed using the mode split and vehicle occupancy values provided in Table 2-A
0
*Indicates computation that has been rounded to the nearest whole number.
0
0
0
0
0
Destination (To)
Cinema/Entertainment
0
3Total estimate for all other land uses at mixed-use development site is not subject to internal trip capture computations in this estimator
Destination Land Use
Table 9-A (O): Internal and External Trips Summary (Exiting Trips)
NCHRP Report 684 estimator PHASE 2.xlsx, Page 2-A
10/31/2018
APPENDIX B (page 3)
Project Name: Organization:
Project Location: Performed By:
Scenario Description: Date:
Analysis Year: Checked By:
Analysis Period: Date:
ITE LUCs1 Quantity Units Total Entering Exiting
Office 0 - GFA 0 0 0
Retail 815,920 4,852 GFA 12 6 6
Restaurant 930,936 - GFA 0 0 0
Cinema/Entertainment - - - 0 0 0
Residential 221 481 DU 212 129 83
Hotel - - - 0
All Other Land Uses2 - - - 0
224 135 89
Veh. Occ.4 % Transit % Non-Motorized Veh. Occ.4 % Transit % Non-Motorized
Office
Retail
Restaurant
Cinema/Entertainment
Residential
Hotel
All Other Land Uses2
Office Retail Restaurant Residential Hotel
Office 0 0 0
Retail
Restaurant
Cinema/Entertainment
Residential 0 0
Hotel
Office Retail Restaurant Residential Hotel
Office 0 0 0 0
Retail 0 0 2 0
Restaurant 0 0 0 0
Cinema/Entertainment 0 0 0 0 0
Residential 0 1 0 0
Hotel 0 0 0 0
Total Entering Exiting Land Use Entering Trips Exiting Trips
All Person-Trips 224 135 89 Office N/A N/A
Internal Capture Percentage 3% 2% 3% Retail 17% 33%
Restaurant N/A N/A
External Vehicle-Trips5 218 132 86 Cinema/Entertainment N/A N/A
External Transit-Trips6 0 0 0 Residential 2% 1%
External Non-Motorized Trips6 0 0 0 Hotel N/A N/A
1Land Use Codes (LUCs) from Trip Generation Manual , published by the Institute of Transportation Engineers.
2Total estimate for all other land uses at mixed-use development site is not subject to internal trip capture computations in this estimator.
3Enter trips assuming no transit or non-motorized trips (as assumed in ITE Trip Generation Manual ).
5Vehicle-trips computed using the mode split and vehicle occupancy values provided in Table 2-P.
Table 5-P: Computations Summary Table 6-P: Internal Trip Capture Percentages by Land Use
4Enter vehicle occupancy assumed in Table 1-P vehicle trips. If vehicle occupancy changes for proposed mixed-use project, manual adjustments must be
6Person-Trips
0
0
0
0
Table 4-P: Internal Person-Trip Origin-Destination Matrix*
Origin (From)Destination (To)
Cinema/Entertainment
0
Table 3-P: Average Land Use Interchange Distances (Feet Walking Distance)
Origin (From)Destination (To)
Cinema/Entertainment
NCHRP 684 Internal Trip Capture Estimation Tool
Cedar River Apartments William Popp Associates
1915 Maple Valley Highway, Renton Bill Popp Jr.
*Indicates computation that has been rounded to the nearest whole number.
Estimation Tool Developed by the Texas A&M Transportation Institute - Version 2013.1
Phase A & B 24-Oct-18
At Full Occupancy
PM Street Peak Hour
Table 1-P: Base Vehicle-Trip Generation Estimates (Single-Use Site Estimate)
Land Use Development Data (For Information Only )Estimated Vehicle-Trips3
Table 2-P: Mode Split and Vehicle Occupancy Estimates
Land Use Entering Trips Exiting Trips
NCHRP Report 684 estimator PHASE 2.xlsx, Page 1-P
10/31/2018
APPENDIX B (page 4)
Project Name:
Analysis Period:
Veh. Occ. Vehicle-Trips Person-Trips* Veh. Occ. Vehicle-Trips Person-Trips*
Office 1.00 0 0 1.00 0 0
Retail 1.00 6 6 1.00 6 6
Restaurant 1.00 0 0 1.00 0 0
Cinema/Entertainment 1.00 0 0 1.00 0 0
Residential 1.00 129 129 1.00 83 83
Hotel 1.00 0 0 1.00 0 0
Office Retail Restaurant Residential Hotel
Office 0 0 0 0
Retail 0 2 2 0
Restaurant 0 0 0 0
Cinema/Entertainment 0 0 0 0 0
Residential 3 35 17 2
Hotel 0 0 0 0
Office Retail Restaurant Residential Hotel
Office 0 0 5 0
Retail 0 0 59 0
Restaurant 0 3 21 0
Cinema/Entertainment 0 0 0 5 0
Residential 0 1 0 0
Hotel 0 0 0 0
Internal External Total Vehicles1 Transit2 Non-Motorized2
Office 0 0 0 0 0 0
Retail 1 5 6 5 0 0
Restaurant 0 0 0 0 0 0
Cinema/Entertainment 0 0 0 0 0 0
Residential 2 127 129 127 0 0
Hotel 0 0 0 0 0 0
All Other Land Uses3 000 0 0 0
Internal External Total Vehicles1 Transit2 Non-Motorized2
Office 0 0 0 0 0 0
Retail 2 4 6 4 0 0
Restaurant 0 0 0 0 0 0
Cinema/Entertainment 0 0 0 0 0 0
Residential 1 82 83 82 0 0
Hotel 0 0 0 0 0 0
All Other Land Uses3 000 0 0 0
0
0
0
0
0
3Total estimate for all other land uses at mixed-use development site is not subject to internal trip capture computations in this estimator
Table 9-P (O): Internal and External Trips Summary (Exiting Trips)
Origin Land Use Person-Trip Estimates External Trips by Mode*
Person-Trip Estimates External Trips by Mode*
0
Table 8-P (D): Internal Person-Trip Origin-Destination Matrix (Computed at Destination)
Origin (From)
2Person-Trips
0
0
Table 9-P (D): Internal and External Trips Summary (Entering Trips)
Destination Land Use
*Indicates computation that has been rounded to the nearest whole number.
Cedar River Apartments
PM Street Peak Hour
Table 7-P: Conversion of Vehicle-Trip Ends to Person-Trip Ends
Land Use Table 7-P (D): Entering Trips Table 7-P (O): Exiting Trips
Table 8-P (O): Internal Person-Trip Origin-Destination Matrix (Computed at Origin)
Origin (From)Destination (To)
Destination (To)
Cinema/Entertainment
Cinema/Entertainment
0
0
1Vehicle-trips computed using the mode split and vehicle occupancy values provided in Table 2-P
NCHRP Report 684 estimator PHASE 2.xlsx, NCHRP Report 684 estimator PHASE 2.xlsx
10/31/2018
APPENDIX B (page 5)
Project Name: Organization:
Project Location: Performed By:
Scenario Description:Date:
Analysis Year: Checked By:
Analysis Period:Date:
ITE LUCs1 Quantity Units Total Entering Exiting
Office 720 25,000 GFA 70 55 15
Retail 815,920 4,852 GFA 5 3 2
Restaurant 930,936 - GFA 0 0 0
Cinema/Entertainment 000
Residential 221 481 DU 173 45 128
Hotel 0
All Other Land Uses2 0
248 103 145
Veh. Occ.4 % Transit % Non-Motorized Veh. Occ.4 % Transit % Non-Motorized
Office
Retail
Restaurant
Cinema/Entertainment
Residential
Hotel
All Other Land Uses2
Office Retail Restaurant Residential Hotel
Office
Retail
Restaurant
Cinema/Entertainment
Residential
Hotel
Office Retail Restaurant Residential Hotel
Office 1 0 0 0
Retail 1 0 0 0
Restaurant 0 0 0 0
Cinema/Entertainment 0 0 0 0 0
Residential 2 1 0 0
Hotel 0 0 0 0
Total Entering Exiting Land Use Entering Trips Exiting Trips
All Person-Trips 248 103 145 Office 5% 7%
Internal Capture Percentage 4% 5% 3% Retail 67% 50%
Restaurant N/A N/A
External Vehicle-Trips5 238 98 140 Cinema/Entertainment N/A N/A
External Transit-Trips6 0 0 0 Residential 0% 2%
External Non-Motorized Trips6 0 0 0 Hotel N/A N/A
1915 Maple Valley Highway, Renton
AM Street Peak Hour
William Popp Associates
Bill Popp Jr.
At Full Occupancy
24-Oct-18Phase A & B & C
Estimation Tool Developed by the Texas A&M Transportation Institute - Version 2013.1
Table 5-A: Computations Summary Table 6-A: Internal Trip Capture Percentages by Land Use
2Total estimate for all other land uses at mixed-use development site is not subject to internal trip capture computations in this estimator.
5Vehicle-trips computed using the mode split and vehicle occupancy values provided in Table 2-A.
1Land Use Codes (LUCs) from Trip Generation Manual , published by the Institute of Transportation Engineers.
6Person-Trips
*Indicates computation that has been rounded to the nearest whole number.
3Enter trips assuming no transit or non-motorized trips (as assumed in ITE Trip Generation Manual ).
4Enter vehicle occupancy assumed in Table 1-A vehicle trips. If vehicle occupancy changes for proposed mixed-use project, manual adjustments must be made
to Tables 5-A, 9-A (O and D). Enter transit, non-motorized percentages that will result with proposed mixed-use project complete.
Table 2-A: Mode Split and Vehicle Occupancy Estimates
Table 4-A: Internal Person-Trip Origin-Destination Matrix*
Destination (To)Origin (From)
Origin (From)Destination (To)
Cinema/Entertainment
Land Use Entering Trips Exiting Trips
Table 3-A: Average Land Use Interchange Distances (Feet Walking Distance)
NCHRP 684 Internal Trip Capture Estimation Tool
Table 1-A: Base Vehicle-Trip Generation Estimates (Single-Use Site Estimate)
0
0
Cinema/Entertainment
Development Data (For Information Only )
0
0
0
Estimated Vehicle-Trips3
Land Use
Cedar River Apartments
NCHRP Report 684 estimator PHASE 3.xlsx, Page 1-A
10/31/2018
APPENDIX B (page 6)
Project Name:
Analysis Period:
Veh. Occ. Vehicle-Trips Person-Trips* Veh. Occ. Vehicle-Trips Person-Trips*
Office 1.00 55 55 1.00 15 15
Retail 1.00 3 3 1.00 1.5 2
Restaurant 1.00 0 0 1.00 0 0
Cinema/Entertainment 1.00 0 0 1.00 0 0
Residential 1.00 45 45 1.00 128 128
Hotel 1.00 0 0 1.00 0 0
Office Retail Restaurant Residential Hotel
Office 4 9 0 0
Retail 1 0 0 0
Restaurant 0 0 0 0
Cinema/Entertainment 0 0 0 0 0
Residential 3 1 26 0
Hotel 0 0 0 0
Office Retail Restaurant Residential Hotel
Office 1 0 0 0
Retail 2 0 1 0
Restaurant 8 0 2 0
Cinema/Entertainment 0 0 0 0 0
Residential 2 1 0 0
Hotel 2 0 0 0
Internal External Total Vehicles1 Transit2 Non-Motorized2
Office 3 52 55 52 0 0
Retail 2 1 3 1 0 0
Restaurant 0 0 0 0 0 0
Cinema/Entertainment 0 0 0 0 0 0
Residential 0 45 45 45 0 0
Hotel 0 0 0 0 0 0
All Other Land Uses3 00 0 0 0 0
Internal External Total Vehicles1 Transit2 Non-Motorized2
Office 1 14 15 14 0 0
Retail 1 1 2 1 0 0
Restaurant 0 0 0 0 0 0
Cinema/Entertainment 0 0 0 0 0 0
Residential 3 125 128 125 0 0
Hotel 0 0 0 0 0 0
All Other Land Uses3 00 0 0 0 0
Land Use
Table 7-A (D): Entering Trips
2Person-Trips
Person-Trip Estimates
Cedar River Apartments
AM Street Peak Hour
Table 9-A (D): Internal and External Trips Summary (Entering Trips)
Table 8-A (O): Internal Person-Trip Origin-Destination Matrix (Computed at Origin)
Origin (From)
Destination (To)
Cinema/Entertainment
Table 7-A: Conversion of Vehicle-Trip Ends to Person-Trip Ends
Table 7-A (O): Exiting Trips
0
0
0
Table 8-A (D): Internal Person-Trip Origin-Destination Matrix (Computed at Destination)
Origin (From)
Origin Land Use Person-Trip Estimates External Trips by Mode*
External Trips by Mode*
1Vehicle-trips computed using the mode split and vehicle occupancy values provided in Table 2-A
0
*Indicates computation that has been rounded to the nearest whole number.
0
0
0
0
0
Destination (To)
Cinema/Entertainment
0
3Total estimate for all other land uses at mixed-use development site is not subject to internal trip capture computations in this estimator
Destination Land Use
Table 9-A (O): Internal and External Trips Summary (Exiting Trips)
NCHRP Report 684 estimator PHASE 3.xlsx, Page 2-A
10/31/2018
APPENDIX B (page 7)
Project Name: Organization:
Project Location: Performed By:
Scenario Description: Date:
Analysis Year: Checked By:
Analysis Period: Date:
ITE LUCs1 Quantity Units Total Entering Exiting
Office 720 25,000 GFA 87 24 63
Retail 815,920 4,852 GFA 12 6 6
Restaurant 930,936 - GFA 0 0 0
Cinema/Entertainment - - - 0 0 0
Residential 221 481 DU 212 129 83
Hotel - - - 0
All Other Land Uses2 - - - 0
311 159 152
Veh. Occ.4 % Transit % Non-Motorized Veh. Occ.4 % Transit % Non-Motorized
Office
Retail
Restaurant
Cinema/Entertainment
Residential
Hotel
All Other Land Uses2
Office Retail Restaurant Residential Hotel
Office 0 0 0
Retail
Restaurant
Cinema/Entertainment
Residential 0 0
Hotel
Office Retail Restaurant Residential Hotel
Office 0 0 1 0
Retail 0 0 2 0
Restaurant 0 0 0 0
Cinema/Entertainment 0 0 0 0 0
Residential 3 1 0 0
Hotel 0 0 0 0
Total Entering Exiting Land Use Entering Trips Exiting Trips
All Person-Trips 311 159 152 Office 13% 2%
Internal Capture Percentage 5% 4% 5% Retail 17% 33%
Restaurant N/A N/A
External Vehicle-Trips5 297 152 145 Cinema/Entertainment N/A N/A
External Transit-Trips6 0 0 0 Residential 2% 5%
External Non-Motorized Trips6 0 0 0 Hotel N/A N/A
1Land Use Codes (LUCs) from Trip Generation Manual , published by the Institute of Transportation Engineers.
2Total estimate for all other land uses at mixed-use development site is not subject to internal trip capture computations in this estimator.
3Enter trips assuming no transit or non-motorized trips (as assumed in ITE Trip Generation Manual ).
5Vehicle-trips computed using the mode split and vehicle occupancy values provided in Table 2-P.
Table 5-P: Computations Summary Table 6-P: Internal Trip Capture Percentages by Land Use
4Enter vehicle occupancy assumed in Table 1-P vehicle trips. If vehicle occupancy changes for proposed mixed-use project, manual adjustments must be
6Person-Trips
0
0
0
0
Table 4-P: Internal Person-Trip Origin-Destination Matrix*
Origin (From)Destination (To)
Cinema/Entertainment
0
Table 3-P: Average Land Use Interchange Distances (Feet Walking Distance)
Origin (From)Destination (To)
Cinema/Entertainment
NCHRP 684 Internal Trip Capture Estimation Tool
Cedar River Apartments William Popp Associates
1915 Maple Valley Highway, Renton Bill Popp Jr.
*Indicates computation that has been rounded to the nearest whole number.
Estimation Tool Developed by the Texas A&M Transportation Institute - Version 2013.1
Phase A & B & C 24-Oct-18
At Full Occupancy
PM Street Peak Hour
Table 1-P: Base Vehicle-Trip Generation Estimates (Single-Use Site Estimate)
Land Use Development Data (For Information Only )Estimated Vehicle-Trips3
Table 2-P: Mode Split and Vehicle Occupancy Estimates
Land Use Entering Trips Exiting Trips
NCHRP Report 684 estimator PHASE 3.xlsx, Page 1-P
10/31/2018
APPENDIX B (page 8)
Project Name:
Analysis Period:
Veh. Occ. Vehicle-Trips Person-Trips* Veh. Occ. Vehicle-Trips Person-Trips*
Office 1.00 24 24 1.00 63 63
Retail 1.00 6 6 1.00 6 6
Restaurant 1.00 0 0 1.00 0 0
Cinema/Entertainment 1.00 0 0 1.00 0 0
Residential 1.00 129 129 1.00 83 83
Hotel 1.00 0 0 1.00 0 0
Office Retail Restaurant Residential Hotel
Office 13 3 1 0
Retail 0 2 2 0
Restaurant 0 0 0 0
Cinema/Entertainment 0 0 0 0 0
Residential 3 35 17 2
Hotel 0 0 0 0
Office Retail Restaurant Residential Hotel
Office 0 0 5 0
Retail 7 0 59 0
Restaurant 7 3 21 0
Cinema/Entertainment 1 0 0 5 0
Residential 14 1 0 0
Hotel 0 0 0 0
Internal External Total Vehicles1 Transit2 Non-Motorized2
Office 3 21 24 21 0 0
Retail 1 5 6 5 0 0
Restaurant 0 0 0 0 0 0
Cinema/Entertainment 0 0 0 0 0 0
Residential 3 126 129 126 0 0
Hotel 0 0 0 0 0 0
All Other Land Uses3 000 0 0 0
Internal External Total Vehicles1 Transit2 Non-Motorized2
Office 1 62 63 62 0 0
Retail 2 4 6 4 0 0
Restaurant 0 0 0 0 0 0
Cinema/Entertainment 0 0 0 0 0 0
Residential 4 79 83 79 0 0
Hotel 0 0 0 0 0 0
All Other Land Uses3 000 0 0 0
0
0
0
0
0
3Total estimate for all other land uses at mixed-use development site is not subject to internal trip capture computations in this estimator
Table 9-P (O): Internal and External Trips Summary (Exiting Trips)
Origin Land Use Person-Trip Estimates External Trips by Mode*
Person-Trip Estimates External Trips by Mode*
0
Table 8-P (D): Internal Person-Trip Origin-Destination Matrix (Computed at Destination)
Origin (From)
2Person-Trips
0
0
Table 9-P (D): Internal and External Trips Summary (Entering Trips)
Destination Land Use
*Indicates computation that has been rounded to the nearest whole number.
Cedar River Apartments
PM Street Peak Hour
Table 7-P: Conversion of Vehicle-Trip Ends to Person-Trip Ends
Land Use Table 7-P (D): Entering Trips Table 7-P (O): Exiting Trips
Table 8-P (O): Internal Person-Trip Origin-Destination Matrix (Computed at Origin)
Origin (From)Destination (To)
Destination (To)
Cinema/Entertainment
Cinema/Entertainment
0
0
1Vehicle-trips computed using the mode split and vehicle occupancy values provided in Table 2-P
NCHRP Report 684 estimator PHASE 3.xlsx, NCHRP Report 684 estimator PHASE 3.xlsx
10/31/2018
$33(1',;&$33(1',;&$33(1',;&$33(1',;&
AM AND PM PEAK HOUR LEVEL OF SERVICE
CALCULATIONS AM AND
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Cedar River Apartments 10/29/2018 2017 existing AM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Traffic Volume (veh/h) 395 104 47 775 578 895000261853439
Future Volume (veh/h) 395 104 47 775 578 895 0 0 0 261 853 439
Number 5 2 12 1 6 16 7 4 14
Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1765 1800 1765 1765 1765 1765 1765 1765
Adj Flow Rate, veh/h 439 116 0 861 642 994 290 948 488
Adj No. of Lanes 220121 121
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222222 222
Cap, veh/h 373 383 0 768 1533 1200 576 1210 686
Arrive On Green 0.11 0.11 0.00 0.76 0.76 0.76 0.34 0.34 0.34
Sat Flow, veh/h 3261 3441 0 1681 3353 1500 1681 3529 1500
Grp Volume(v), veh/h 439 116 0 861 642 994 290 948 488
Grp Sat Flow(s),veh/h/ln 1630 1676 0 1681 1676 1500 1681 1765 1500
Q Serve(g_s), s 16.0 4.4 0.0 64.0 9.3 64.0 19.2 33.8 36.6
Cycle Q Clear(g_c), s 16.0 4.4 0.0 64.0 9.3 64.0 19.2 33.8 36.6
Prop In Lane 1.00 0.00 1.00 1.00 1.00 1.00
Lane Grp Cap(c), veh/h 373 383 0 768 1533 1200 576 1210 686
V/C Ratio(X) 1.18 0.30 0.00 1.12 0.42 0.83 0.50 0.78 0.71
Avail Cap(c_a), veh/h 373 383 0 768 1533 1200 576 1210 686
HCM Platoon Ratio 1.00 1.00 1.00 1.67 1.67 1.67 1.00 1.00 1.00
Upstream Filter(I) 1.00 1.00 0.00 0.22 0.22 0.22 0.40 0.40 0.40
Uniform Delay (d), s/veh 62.0 56.9 0.0 16.6 10.1 4.0 36.5 41.3 30.6
Incr Delay (d2), s/veh 104.6 0.4 0.0 58.8 0.0 1.2 1.2 2.1 2.5
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 12.6 2.1 0.0 41.0 4.2 38.6 9.1 16.8 18.8
LnGrp Delay(d),s/veh 166.6 57.3 0.0 75.4 10.1 5.2 37.8 43.4 33.1
LnGrp LOS F E F B A D D C
Approach Vol, veh/h 555 2497 1726
Approach Delay, s/veh 143.8 30.6 39.6
Approach LOS F C D
Timer 12345678
Assigned Phs 2 4 6
Phs Duration (G+Y+Rc), s 20.0 52.0 68.0
Change Period (Y+Rc), s 5.0 5.0 5.0
Max Green Setting (Gmax), s 15.0 47.0 63.0
Max Q Clear Time (g_c+I1), s 18.0 38.6 66.0
Green Ext Time (p_c), s 0.0 5.2 0.0
Intersection Summary
HCM 2010 Ctrl Delay 47.0
HCM 2010 LOS D
Notes
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,1%2II5DPS,1%2Q5DPS 6510/29/2018
Cedar River Apartments 10/29/2018 2017 existing AM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Traffic Volume (vph) 17 348 0 0 1706 412 0 0 289 0 0 495
Future Volume (vph) 17 348 0 0 1706 412 0 0 289 0 0 495
Ideal Flow (vphpl) 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800
Total Lost time (s) 4.0 4.0 4.0 4.0 4.0 4.0
Lane Util. Factor 1.00 0.95 *0.70 1.00 1.00 1.00
Frt 1.00 1.00 1.00 0.85 0.86 0.86
Flt Protected 0.95 1.00 1.00 1.00 1.00 1.00
Satd. Flow (prot) 1621 3241 3582 1450 1476 1476
Flt Permitted 0.95 1.00 1.00 1.00 1.00 1.00
Satd. Flow (perm) 1621 3241 3582 1450 1476 1476
Peak-hour factor, PHF 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90
Adj. Flow (vph) 19 387 0 0 1896 458 0 0 321 0 0 550
RTOR Reduction (vph)000001420000010
Lane Group Flow (vph) 19 387 0 0 1896 316 0 0 321 0 0 540
Turn Type Prot NA NA Perm Free Over
Protected Phases 5 2 6 5
Permitted Phases 6 Free
Actuated Green, G (s) 51.5 140.0 78.5 78.5 140.0 51.5
Effective Green, g (s) 52.5 140.0 79.5 79.5 140.0 52.5
Actuated g/C Ratio 0.38 1.00 0.57 0.57 1.00 0.38
Clearance Time (s) 5.0 5.0 5.0 5.0 5.0
Vehicle Extension (s) 3.0 3.0 3.0 3.0 3.0
Lane Grp Cap (vph) 607 3241 2034 823 1476 553
v/s Ratio Prot 0.01 0.12 c0.53 c0.37
v/s Ratio Perm 0.22 0.22
v/c Ratio 0.03 0.12 0.93 0.38 0.22 0.98
Uniform Delay, d1 27.7 0.0 27.8 16.7 0.0 43.1
Progression Factor 1.55 1.00 0.74 0.23 1.00 1.00
Incremental Delay, d2 0.0 0.1 9.3 1.4 0.3 32.0
Delay (s) 43.0 0.1 29.9 5.1 0.3 75.1
Level of Service D A C A A E
Approach Delay (s) 2.1 25.0 0.3 75.1
Approach LOS A C A E
Intersection Summary
HCM 2000 Control Delay 27.9 HCM 2000 Level of Service C
HCM 2000 Volume to Capacity ratio 0.95
Actuated Cycle Length (s) 140.0 Sum of lost time (s) 8.0
Intersection Capacity Utilization 73.8% ICU Level of Service D
Analysis Period (min) 15
Description: SR 169/I-405 NB On-Ramp
c Critical Lane Group
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Cedar River Apartments 10/29/2018 2017 existing AM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBU EBL EBT WBT WBR SBL SBR
Lane Configurations
Traffic Volume (veh/h) 55 35 640 2008 7 3 55
Future Volume (veh/h) 55 35 640 2008 7 3 55
Number 5 2 6 16 7 14
Initial Q (Qb), veh 0 0 0000
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1765 1765 1800 1765 1800
Adj Flow Rate, veh/h 39 711 2231 8 3 61
Adj No. of Lanes 134000
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222200
Cap, veh/h 61 3256 4433 16 4 91
Arrive On Green 0.07 1.00 1.00 1.00 0.06 0.06
Sat Flow, veh/h 1681 4235 5977 20 70 1418
Grp Volume(v), veh/h 39 711 1518 721 65 0
Grp Sat Flow(s),veh/h/ln 1681 1235 1235 1761 1511 0
Q Serve(g_s), s 3.2 0.0 0.0 0.0 5.9 0.0
Cycle Q Clear(g_c), s 3.2 0.0 0.0 0.0 5.9 0.0
Prop In Lane 1.00 0.01 0.05 0.94
Lane Grp Cap(c), veh/h 61 3256 3016 1433 97 0
V/C Ratio(X) 0.64 0.22 0.50 0.50 0.67 0.00
Avail Cap(c_a), veh/h 216 3256 3016 1433 194 0
HCM Platoon Ratio 2.00 2.00 2.00 2.00 1.00 1.00
Upstream Filter(I) 0.99 0.99 0.75 0.75 1.00 0.00
Uniform Delay (d), s/veh 64.0 0.0 0.0 0.0 64.5 0.0
Incr Delay (d2), s/veh 10.6 0.2 0.5 0.9 7.7 0.0
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 1.7 0.0 0.1 0.4 2.7 0.0
LnGrp Delay(d),s/veh 74.7 0.2 0.5 0.9 72.2 0.0
LnGrp LOS EAAAE
Approach Vol, veh/h 750 2239 65
Approach Delay, s/veh 4.0 0.6 72.2
Approach LOS A A E
Timer 12345678
Assigned Phs 2 4 5 6
Phs Duration (G+Y+Rc), s 127.0 13.0 9.1 117.9
Change Period (Y+Rc), s 5.0 5.0 5.0 5.0
Max Green Setting (Gmax), s 113.0 17.0 17.0 91.0
Max Q Clear Time (g_c+I1), s 2.0 7.9 5.2 2.0
Green Ext Time (p_c), s 36.3 0.1 0.1 34.5
Intersection Summary
HCM 2010 Ctrl Delay 3.0
HCM 2010 LOS A
Notes
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&HGDU5LYHU3DUN'U 6510/30/2018
Cedar River Apartments 10/29/2018 2017 existing AM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBT EBR WBL WBT NBL NBR
Lane Configurations
Traffic Volume (veh/h) 623 61 12 1984 31 6
Future Volume (veh/h) 623 61 12 1984 31 6
Number 21216318
Initial Q (Qb), veh 0 0 0 0 0 0
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1800 1765 1765 1765 1765
Adj Flow Rate, veh/h 692 68 13 2204 34 7
Adj No. of Lanes 301311
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222222
Cap, veh/h 2897 283 27 3632 228 204
Arrive On Green 1.00 1.00 0.02 0.81 0.14 0.14
Sat Flow, veh/h 4328 371 1681 4765 1681 1500
Grp Volume(v), veh/h 449 311 13 2204 34 7
Grp Sat Flow(s),veh/h/ln 1235 1699 1681 1500 1681 1500
Q Serve(g_s), s 0.0 0.0 1.1 25.9 2.5 0.6
Cycle Q Clear(g_c), s 0.0 0.0 1.1 25.9 2.5 0.6
Prop In Lane 0.22 1.00 1.00 1.00
Lane Grp Cap(c), veh/h 1884 1296 27 3632 228 204
V/C Ratio(X) 0.24 0.24 0.49 0.61 0.15 0.03
Avail Cap(c_a), veh/h 1884 1296 84 3632 228 204
HCM Platoon Ratio 2.00 2.00 1.00 1.00 1.00 1.00
Upstream Filter(I) 0.98 0.98 1.00 1.00 1.00 1.00
Uniform Delay (d), s/veh 0.0 0.0 68.3 5.1 53.4 52.5
Incr Delay (d2), s/veh 0.3 0.4 13.1 0.8 1.4 0.3
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 0.1 0.2 0.6 10.7 1.2 0.3
LnGrp Delay(d),s/veh 0.3 0.4 81.5 5.9 54.7 52.8
LnGrp LOS A A F A D D
Approach Vol, veh/h 760 2217 41
Approach Delay, s/veh 0.3 6.3 54.4
Approach LOS A A D
Timer 12345678
Assigned Phs 1 2 6 8
Phs Duration (G+Y+Rc), s 6.2 110.8 117.0 23.0
Change Period (Y+Rc), s 5.0 5.0 5.0 5.0
Max Green Setting (Gmax), s 6.0 101.0 112.0 18.0
Max Q Clear Time (g_c+I1), s 3.1 2.0 27.9 4.5
Green Ext Time (p_c), s 0.0 36.8 35.1 0.1
Intersection Summary
HCM 2010 Ctrl Delay 5.5
HCM 2010 LOS A
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,6%2Q5DPS6XQVHW%OYG %URQVRQ:D\6510/30/2018
Cedar River Apartments 10/29/2018 2021 background AM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Traffic Volume (veh/h) 411 108 49 806 601 931000272888457
Future Volume (veh/h) 411 108 49 806 601 931 0 0 0 272 888 457
Number 5 2 12 1 6 16 7 4 14
Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1765 1800 1765 1765 1765 1765 1765 1765
Adj Flow Rate, veh/h 457 120 0 896 668 1034 302 987 508
Adj No. of Lanes 220121 121
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222222 222
Cap, veh/h 396 407 0 756 1509 1189 576 1210 696
Arrive On Green 0.12 0.12 0.00 0.75 0.75 0.75 0.34 0.34 0.34
Sat Flow, veh/h 3261 3441 0 1681 3353 1500 1681 3529 1500
Grp Volume(v), veh/h 457 120 0 896 668 1034 302 987 508
Grp Sat Flow(s),veh/h/ln 1630 1676 0 1681 1676 1500 1681 1765 1500
Q Serve(g_s), s 17.0 4.6 0.0 63.0 10.4 63.0 20.2 35.7 38.4
Cycle Q Clear(g_c), s 17.0 4.6 0.0 63.0 10.4 63.0 20.2 35.7 38.4
Prop In Lane 1.00 0.00 1.00 1.00 1.00 1.00
Lane Grp Cap(c), veh/h 396 407 0 756 1509 1189 576 1210 696
V/C Ratio(X) 1.15 0.29 0.00 1.18 0.44 0.87 0.52 0.82 0.73
Avail Cap(c_a), veh/h 396 407 0 756 1509 1189 576 1210 696
HCM Platoon Ratio 1.00 1.00 1.00 1.67 1.67 1.67 1.00 1.00 1.00
Upstream Filter(I) 1.00 1.00 0.00 0.09 0.09 0.09 0.40 0.40 0.40
Uniform Delay (d), s/veh 61.5 56.0 0.0 17.4 10.9 4.3 36.9 42.0 30.4
Incr Delay (d2), s/veh 94.4 0.4 0.0 84.5 0.0 0.7 1.4 2.5 2.7
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 12.8 2.1 0.0 45.8 4.6 40.0 9.5 17.8 20.0
LnGrp Delay(d),s/veh 155.9 56.4 0.0 101.9 10.9 5.0 38.2 44.5 33.1
LnGrp LOS F E F B A D D C
Approach Vol, veh/h 577 2598 1797
Approach Delay, s/veh 135.2 40.0 40.2
Approach LOS F D D
Timer 12345678
Assigned Phs 2 4 6
Phs Duration (G+Y+Rc), s 21.0 52.0 67.0
Change Period (Y+Rc), s 5.0 5.0 5.0
Max Green Setting (Gmax), s 16.0 47.0 62.0
Max Q Clear Time (g_c+I1), s 19.0 40.4 65.0
Green Ext Time (p_c), s 0.0 4.5 0.0
Intersection Summary
HCM 2010 Ctrl Delay 51.1
HCM 2010 LOS D
Notes
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,1%2II5DPS,1%2Q5DPS 6510/29/2018
Cedar River Apartments 10/29/2018 2021 background AM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Traffic Volume (vph) 18 375 0 0 1812 445 0 0 307 0 0 515
Future Volume (vph) 18 375 0 0 1812 445 0 0 307 0 0 515
Ideal Flow (vphpl) 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800
Total Lost time (s) 4.0 4.0 4.0 4.0 4.0 4.0
Lane Util. Factor 1.00 0.95 *0.70 1.00 1.00 1.00
Frt 1.00 1.00 1.00 0.85 0.86 0.86
Flt Protected 0.95 1.00 1.00 1.00 1.00 1.00
Satd. Flow (prot) 1621 3241 3582 1450 1476 1476
Flt Permitted 0.95 1.00 1.00 1.00 1.00 1.00
Satd. Flow (perm) 1621 3241 3582 1450 1476 1476
Peak-hour factor, PHF 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90
Adj. Flow (vph) 20 417 0 0 2013 494 0 0 341 0 0 572
RTOR Reduction (vph)000001460000010
Lane Group Flow (vph) 20 417 0 0 2013 348 0 0 341 0 0 562
Turn Type Prot NA NA Perm Free Over
Protected Phases 5 2 6 5
Permitted Phases 6 Free
Actuated Green, G (s) 52.0 140.0 78.0 78.0 140.0 52.0
Effective Green, g (s) 53.0 140.0 79.0 79.0 140.0 53.0
Actuated g/C Ratio 0.38 1.00 0.56 0.56 1.00 0.38
Clearance Time (s) 5.0 5.0 5.0 5.0 5.0
Vehicle Extension (s) 3.0 3.0 3.0 3.0 3.0
Lane Grp Cap (vph) 613 3241 2021 818 1476 558
v/s Ratio Prot 0.01 0.13 c0.56 c0.38
v/s Ratio Perm 0.24 0.23
v/c Ratio 0.03 0.13 1.00 0.43 0.23 1.01
Uniform Delay, d1 27.4 0.0 30.3 17.5 0.0 43.5
Progression Factor 1.53 1.00 0.65 0.34 1.00 1.00
Incremental Delay, d2 0.0 0.1 16.9 1.3 0.4 39.9
Delay (s) 41.9 0.1 36.8 7.3 0.4 83.4
Level of Service D A D A A F
Approach Delay (s) 2.0 30.9 0.4 83.4
Approach LOS A C A F
Intersection Summary
HCM 2000 Control Delay 32.7 HCM 2000 Level of Service C
HCM 2000 Volume to Capacity ratio 1.00
Actuated Cycle Length (s) 140.0 Sum of lost time (s) 8.0
Intersection Capacity Utilization 77.3% ICU Level of Service D
Analysis Period (min) 15
Description: SR 169/I-405 NB On-Ramp
c Critical Lane Group
+&06LJQDOL]HG,QWHUVHFWLRQ6XPPDU\
65 6KDUL
V'ULYHZD\10/30/2018
Cedar River Apartments 10/29/2018 2021 background AM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBU EBL EBT WBT WBR SBL SBR
Lane Configurations
Traffic Volume (veh/h) 57 36 666 2090 7 3 57
Future Volume (veh/h) 57 36 666 2090 7 3 57
Number 5 2 6 16 7 14
Initial Q (Qb), veh 0 0 0000
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1765 1765 1800 1765 1800
Adj Flow Rate, veh/h 40 740 2322 8 3 63
Adj No. of Lanes 134000
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222200
Cap, veh/h 62 3251 4422 15 4 93
Arrive On Green 0.07 1.00 1.00 1.00 0.07 0.06
Sat Flow, veh/h 1681 4235 5978 19 68 1420
Grp Volume(v), veh/h 40 740 1579 751 67 0
Grp Sat Flow(s),veh/h/ln 1681 1235 1235 1761 1511 0
Q Serve(g_s), s 3.2 0.0 0.0 0.0 6.1 0.0
Cycle Q Clear(g_c), s 3.2 0.0 0.0 0.0 6.1 0.0
Prop In Lane 1.00 0.01 0.04 0.94
Lane Grp Cap(c), veh/h 62 3251 3008 1430 99 0
V/C Ratio(X) 0.64 0.23 0.53 0.53 0.68 0.00
Avail Cap(c_a), veh/h 228 3251 3008 1430 183 0
HCM Platoon Ratio 2.00 2.00 2.00 2.00 1.00 1.00
Upstream Filter(I) 0.99 0.99 0.72 0.72 1.00 0.00
Uniform Delay (d), s/veh 63.9 0.0 0.0 0.0 64.4 0.0
Incr Delay (d2), s/veh 10.5 0.2 0.5 1.0 7.8 0.0
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 1.7 0.0 0.1 0.4 2.8 0.0
LnGrp Delay(d),s/veh 74.4 0.2 0.5 1.0 72.2 0.0
LnGrp LOS EAAAE
Approach Vol, veh/h 780 2330 67
Approach Delay, s/veh 4.0 0.6 72.2
Approach LOS A A E
Timer 12345678
Assigned Phs 2 4 5 6
Phs Duration (G+Y+Rc), s 126.8 13.2 9.2 117.6
Change Period (Y+Rc), s 5.0 5.0 5.0 5.0
Max Green Setting (Gmax), s 114.0 16.0 18.0 91.0
Max Q Clear Time (g_c+I1), s 2.0 8.1 5.2 2.0
Green Ext Time (p_c), s 40.3 0.1 0.1 37.8
Intersection Summary
HCM 2010 Ctrl Delay 3.0
HCM 2010 LOS A
Notes
+&06LJQDOL]HG,QWHUVHFWLRQ6XPPDU\
&HGDU5LYHU3DUN'U 6510/30/2018
Cedar River Apartments 10/29/2018 2021 background AM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBT EBR WBL WBT NBL NBR
Lane Configurations
Traffic Volume (veh/h) 648 63 12 2065 32 6
Future Volume (veh/h) 648 63 12 2065 32 6
Number 21216318
Initial Q (Qb), veh 0 0 0 0 0 0
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1800 1765 1765 1765 1765
Adj Flow Rate, veh/h 720 70 13 2294 36 7
Adj No. of Lanes 301311
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222222
Cap, veh/h 2900 281 27 3632 228 204
Arrive On Green 1.00 1.00 0.02 0.81 0.14 0.14
Sat Flow, veh/h 4332 368 1681 4765 1681 1500
Grp Volume(v), veh/h 467 323 13 2294 36 7
Grp Sat Flow(s),veh/h/ln 1235 1700 1681 1500 1681 1500
Q Serve(g_s), s 0.0 0.0 1.1 28.1 2.6 0.6
Cycle Q Clear(g_c), s 0.0 0.0 1.1 28.1 2.6 0.6
Prop In Lane 0.22 1.00 1.00 1.00
Lane Grp Cap(c), veh/h 1884 1296 27 3632 228 204
V/C Ratio(X) 0.25 0.25 0.49 0.63 0.16 0.03
Avail Cap(c_a), veh/h 1884 1296 84 3632 228 204
HCM Platoon Ratio 2.00 2.00 1.00 1.00 1.00 1.00
Upstream Filter(I) 0.98 0.98 1.00 1.00 1.00 1.00
Uniform Delay (d), s/veh 0.0 0.0 68.3 5.3 53.4 52.5
Incr Delay (d2), s/veh 0.3 0.5 13.1 0.8 1.5 0.3
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 0.1 0.2 0.6 11.8 1.3 0.3
LnGrp Delay(d),s/veh 0.3 0.5 81.5 6.2 54.9 52.8
LnGrp LOS A A F A D D
Approach Vol, veh/h 790 2307 43
Approach Delay, s/veh 0.4 6.6 54.6
Approach LOS A A D
Timer 12345678
Assigned Phs 1 2 6 8
Phs Duration (G+Y+Rc), s 6.2 110.8 117.0 23.0
Change Period (Y+Rc), s 5.0 5.0 5.0 5.0
Max Green Setting (Gmax), s 6.0 101.0 112.0 18.0
Max Q Clear Time (g_c+I1), s 3.1 2.0 30.1 4.6
Green Ext Time (p_c), s 0.0 40.7 38.1 0.1
Intersection Summary
HCM 2010 Ctrl Delay 5.7
HCM 2010 LOS A
+&06LJQDOL]HG,QWHUVHFWLRQ6XPPDU\
,6%2Q5DPS6XQVHW%OYG %URQVRQ:D\6510/30/2018
Cedar River Apartments 10/29/2018 AM Peak 2021 Phase 1 Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Traffic Volume (veh/h) 411 110 49 822 607 946000283888457
Future Volume (veh/h) 411 110 49 822 607 946 0 0 0 283 888 457
Number 5 2 12 1 6 16 7 4 14
Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1765 1800 1765 1765 1765 1765 1765 1765
Adj Flow Rate, veh/h 457 122 0 913 674 1051 314 987 508
Adj No. of Lanes 220121 121
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222222 222
Cap, veh/h 396 407 0 768 1533 1189 564 1185 686
Arrive On Green 0.12 0.12 0.00 0.76 0.76 0.76 0.34 0.34 0.34
Sat Flow, veh/h 3261 3441 0 1681 3353 1500 1681 3529 1500
Grp Volume(v), veh/h 457 122 0 913 674 1051 314 987 508
Grp Sat Flow(s),veh/h/ln 1630 1676 0 1681 1676 1500 1681 1765 1500
Q Serve(g_s), s 17.0 4.6 0.0 64.0 10.0 64.0 21.4 36.1 38.9
Cycle Q Clear(g_c), s 17.0 4.6 0.0 64.0 10.0 64.0 21.4 36.1 38.9
Prop In Lane 1.00 0.00 1.00 1.00 1.00 1.00
Lane Grp Cap(c), veh/h 396 407 0 768 1533 1189 564 1185 686
V/C Ratio(X) 1.15 0.30 0.00 1.19 0.44 0.88 0.56 0.83 0.74
Avail Cap(c_a), veh/h 396 407 0 768 1533 1189 564 1185 686
HCM Platoon Ratio 1.00 1.00 1.00 1.67 1.67 1.67 1.00 1.00 1.00
Upstream Filter(I) 1.00 1.00 0.00 0.09 0.09 0.09 0.40 0.40 0.40
Uniform Delay (d), s/veh 61.5 56.1 0.0 16.6 10.2 4.2 38.0 42.9 31.2
Incr Delay (d2), s/veh 94.4 0.4 0.0 86.1 0.0 0.9 1.6 2.9 2.9
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 12.8 2.2 0.0 46.8 4.5 40.7 10.2 18.0 20.2
LnGrp Delay(d),s/veh 155.9 56.5 0.0 102.7 10.2 5.1 39.6 45.8 34.1
LnGrp LOS F E F B A D D C
Approach Vol, veh/h 579 2638 1809
Approach Delay, s/veh 135.0 40.2 41.4
Approach LOS F D D
Timer 12345678
Assigned Phs 2 4 6
Phs Duration (G+Y+Rc), s 21.0 51.0 68.0
Change Period (Y+Rc), s 5.0 5.0 5.0
Max Green Setting (Gmax), s 16.0 46.0 63.0
Max Q Clear Time (g_c+I1), s 19.0 40.9 66.0
Green Ext Time (p_c), s 0.0 3.6 0.0
Intersection Summary
HCM 2010 Ctrl Delay 51.5
HCM 2010 LOS D
Notes
+&06LJQDOL]HG,QWHUVHFWLRQ&DSDFLW\$QDO\VLV
,1%2II5DPS,1%2Q5DPS 6510/29/2018
Cedar River Apartments 10/29/2018 AM Peak 2021 Phase 1 Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Traffic Volume (vph) 18 375 0 0 1812 445 0 0 307 0 0 515
Future Volume (vph) 18 375 0 0 1812 445 0 0 307 0 0 515
Ideal Flow (vphpl) 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800
Total Lost time (s) 4.0 4.0 4.0 4.0 4.0 4.0
Lane Util. Factor 1.00 0.95 *0.70 1.00 1.00 1.00
Frt 1.00 1.00 1.00 0.85 0.86 0.86
Flt Protected 0.95 1.00 1.00 1.00 1.00 1.00
Satd. Flow (prot) 1621 3241 3582 1450 1476 1476
Flt Permitted 0.95 1.00 1.00 1.00 1.00 1.00
Satd. Flow (perm) 1621 3241 3582 1450 1476 1476
Peak-hour factor, PHF 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90
Adj. Flow (vph) 20 417 0 0 2013 494 0 0 341 0 0 572
RTOR Reduction (vph)000001460000010
Lane Group Flow (vph) 20 417 0 0 2013 348 0 0 341 0 0 562
Turn Type Prot NA NA Perm Free Over
Protected Phases 5 2 6 5
Permitted Phases 6 Free
Actuated Green, G (s) 52.0 140.0 78.0 78.0 140.0 52.0
Effective Green, g (s) 53.0 140.0 79.0 79.0 140.0 53.0
Actuated g/C Ratio 0.38 1.00 0.56 0.56 1.00 0.38
Clearance Time (s) 5.0 5.0 5.0 5.0 5.0
Vehicle Extension (s) 3.0 3.0 3.0 3.0 3.0
Lane Grp Cap (vph) 613 3241 2021 818 1476 558
v/s Ratio Prot 0.01 0.13 c0.56 c0.38
v/s Ratio Perm 0.24 0.23
v/c Ratio 0.03 0.13 1.00 0.43 0.23 1.01
Uniform Delay, d1 27.4 0.0 30.3 17.5 0.0 43.5
Progression Factor 1.58 1.00 0.65 0.33 1.00 1.00
Incremental Delay, d2 0.0 0.0 16.3 1.2 0.4 39.9
Delay (s) 43.3 0.0 36.0 7.0 0.4 83.4
Level of Service D A D A A F
Approach Delay (s) 2.0 30.3 0.4 83.4
Approach LOS A C A F
Intersection Summary
HCM 2000 Control Delay 32.3 HCM 2000 Level of Service C
HCM 2000 Volume to Capacity ratio 1.00
Actuated Cycle Length (s) 140.0 Sum of lost time (s) 8.0
Intersection Capacity Utilization 77.3% ICU Level of Service D
Analysis Period (min) 15
Description: SR 169/I-405 NB On-Ramp
c Critical Lane Group
+&06LJQDOL]HG,QWHUVHFWLRQ6XPPDU\
65 6KDUL
V'ULYHZD\10/30/2018
Cedar River Apartments 10/29/2018 AM Peak 2021 Phase 1 Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBU EBL EBT WBT WBR SBL SBR
Lane Configurations
Traffic Volume (veh/h) 57 36 685 2143 7 3 57
Future Volume (veh/h) 57 36 685 2143 7 3 57
Number 5 2 6 16 7 14
Initial Q (Qb), veh 0 0 0000
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1765 1765 1800 1765 1800
Adj Flow Rate, veh/h 40 761 2381 8 3 63
Adj No. of Lanes 134000
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222200
Cap, veh/h 62 3251 4424 15 4 93
Arrive On Green 0.07 1.00 1.00 1.00 0.07 0.06
Sat Flow, veh/h 1681 4235 5978 18 68 1420
Grp Volume(v), veh/h 40 761 1619 770 67 0
Grp Sat Flow(s),veh/h/ln 1681 1235 1235 1761 1511 0
Q Serve(g_s), s 3.2 0.0 0.0 0.0 6.1 0.0
Cycle Q Clear(g_c), s 3.2 0.0 0.0 0.0 6.1 0.0
Prop In Lane 1.00 0.01 0.04 0.94
Lane Grp Cap(c), veh/h 62 3251 3009 1430 99 0
V/C Ratio(X) 0.65 0.23 0.54 0.54 0.68 0.00
Avail Cap(c_a), veh/h 132 3251 3009 1430 183 0
HCM Platoon Ratio 2.00 2.00 2.00 2.00 1.00 1.00
Upstream Filter(I) 0.99 0.99 0.71 0.71 1.00 0.00
Uniform Delay (d), s/veh 64.0 0.0 0.0 0.0 64.4 0.0
Incr Delay (d2), s/veh 10.7 0.2 0.5 1.0 7.8 0.0
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 1.7 0.1 0.1 0.4 2.8 0.0
LnGrp Delay(d),s/veh 74.6 0.2 0.5 1.0 72.2 0.0
LnGrp LOS EAAAE
Approach Vol, veh/h 801 2389 67
Approach Delay, s/veh 3.9 0.7 72.2
Approach LOS A A E
Timer 12345678
Assigned Phs 2 4 5 6
Phs Duration (G+Y+Rc), s 126.8 13.2 9.2 117.7
Change Period (Y+Rc), s 5.0 5.0 5.0 5.0
Max Green Setting (Gmax), s 114.0 16.0 10.0 99.0
Max Q Clear Time (g_c+I1), s 2.0 8.1 5.2 2.0
Green Ext Time (p_c), s 43.0 0.1 0.0 41.2
Intersection Summary
HCM 2010 Ctrl Delay 2.9
HCM 2010 LOS A
Notes
+&06LJQDOL]HG,QWHUVHFWLRQ6XPPDU\
&HGDU5LYHU3DUN'U 6510/30/2018
Cedar River Apartments 10/29/2018 AM Peak 2021 Phase 1 Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBT EBR WBL WBT NBL NBR
Lane Configurations
Traffic Volume (veh/h) 648 82 12 2065 86 6
Future Volume (veh/h) 648 82 12 2065 86 6
Number 21216318
Initial Q (Qb), veh 0 0 0 0 0 0
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1800 1765 1765 1765 1765
Adj Flow Rate, veh/h 720 91 13 2294 96 7
Adj No. of Lanes 301311
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222222
Cap, veh/h 2762 347 27 3568 252 225
Arrive On Green 1.00 1.00 0.02 0.79 0.15 0.15
Sat Flow, veh/h 4219 464 1681 4765 1681 1500
Grp Volume(v), veh/h 481 330 13 2294 96 7
Grp Sat Flow(s),veh/h/ln 1235 1683 1681 1500 1681 1500
Q Serve(g_s), s 0.0 0.0 1.1 30.2 7.2 0.6
Cycle Q Clear(g_c), s 0.0 0.0 1.1 30.2 7.2 0.6
Prop In Lane 0.28 1.00 1.00 1.00
Lane Grp Cap(c), veh/h 1849 1260 27 3568 252 225
V/C Ratio(X) 0.26 0.26 0.49 0.64 0.38 0.03
Avail Cap(c_a), veh/h 1849 1260 84 3568 252 225
HCM Platoon Ratio 2.00 2.00 1.00 1.00 1.00 1.00
Upstream Filter(I) 0.98 0.98 1.00 1.00 1.00 1.00
Uniform Delay (d), s/veh 0.0 0.0 68.3 6.1 53.6 50.8
Incr Delay (d2), s/veh 0.3 0.5 13.1 0.9 4.3 0.3
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 0.1 0.2 0.6 12.6 3.7 0.2
LnGrp Delay(d),s/veh 0.3 0.5 81.5 7.0 58.0 51.1
LnGrp LOS A A F A E D
Approach Vol, veh/h 811 2307 103
Approach Delay, s/veh 0.4 7.4 57.5
Approach LOS A A E
Timer 12345678
Assigned Phs 1 2 6 8
Phs Duration (G+Y+Rc), s 6.2 108.8 115.0 25.0
Change Period (Y+Rc), s 5.0 5.0 5.0 5.0
Max Green Setting (Gmax), s 6.0 99.0 110.0 20.0
Max Q Clear Time (g_c+I1), s 3.1 2.0 32.2 9.2
Green Ext Time (p_c), s 0.0 41.0 37.8 0.2
Intersection Summary
HCM 2010 Ctrl Delay 7.3
HCM 2010 LOS A
+&07:6&
6LWH(DVW$FFHVV 6510/29/2018
Cedar River Apartments 10/29/2018 AM Peak 2021 Phase 1 Synchro 9 Light Report
BPJ; William Popp Associates
Intersection
Int Delay, s/veh 0
Movement EBT EBR WBL WBT NBL NBR
Lane Configurations
Traffic Vol, veh/h 655 0 3 2077 0 10
Future Vol, veh/h 655 0 3 2077 0 10
Conflicting Peds, #/hr 000000
Sign Control Free Free Free Free Stop Stop
RT Channelized - None - None - None
Storage Length - 0 150 - 150 0
Veh in Median Storage, # 0 - - 0 0 -
Grade, % 0 - - 0 0 -
Peak Hour Factor 90 90 90 90 90 90
Heavy Vehicles, %222222
Mvmt Flow 728 0 3 2308 0 11
Major/Minor Major1 Major2 Minor1
Conflicting Flow All 0 0 728 0 1658 364
Stage 1 - - - - 728 -
Stage 2 - - - - 930 -
Critical Hdwy - - 4.14 - 6.29 6.94
Critical Hdwy Stg 1 - - - - 5.84 -
Critical Hdwy Stg 2 - - - - 6.04 -
Follow-up Hdwy - - 2.22 - 3.67 3.32
Pot Cap-1 Maneuver - - 871 - 112 633
Stage 1 - - - - 427 -
Stage 2 - - - - 319 -
Platoon blocked, % - - -
Mov Cap-1 Maneuver - - 871 - 112 633
Mov Cap-2 Maneuver - - - - 112 -
Stage 1 - - - - 427 -
Stage 2 - - - - 318 -
Approach EB WB NB
HCM Control Delay, s 0 0 10.8
HCM LOS B
Minor Lane/Major Mvmt NBLn1NBLn2 EBT EBR WBL WBT
Capacity (veh/h) - 633 - - 871 -
HCM Lane V/C Ratio - 0.018 - - 0.004 -
HCM Control Delay (s) 0 10.8 - - 9.1 -
HCM Lane LOS A B - - A -
HCM 95th %tile Q(veh) - 0.1 - - 0 -
+&06LJQDOL]HG,QWHUVHFWLRQ6XPPDU\
,6%2Q5DPS6XQVHW%OYG %URQVRQ:D\6510/30/2018
Cedar River Apartments 10/29/2018 2021 Phase 2 AM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Traffic Volume (veh/h) 415 114 49 847 621 975000297897461
Future Volume (veh/h) 415 114 49 847 621 975 0 0 0 297 897 461
Number 5 2 12 1 6 16 7 4 14
Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1765 1800 1765 1765 1765 1765 1765 1765
Adj Flow Rate, veh/h 461 127 0 941 690 1083 330 997 512
Adj No. of Lanes 220121 121
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222222 222
Cap, veh/h 396 407 0 768 1533 1189 564 1185 686
Arrive On Green 0.12 0.12 0.00 0.61 0.61 0.61 0.34 0.34 0.34
Sat Flow, veh/h 3261 3441 0 1681 3353 1500 1681 3529 1500
Grp Volume(v), veh/h 461 127 0 941 690 1083 330 997 512
Grp Sat Flow(s),veh/h/ln 1630 1676 0 1681 1676 1500 1681 1765 1500
Q Serve(g_s), s 17.0 4.8 0.0 64.0 15.5 64.0 22.7 36.6 39.4
Cycle Q Clear(g_c), s 17.0 4.8 0.0 64.0 15.5 64.0 22.7 36.6 39.4
Prop In Lane 1.00 0.00 1.00 1.00 1.00 1.00
Lane Grp Cap(c), veh/h 396 407 0 768 1533 1189 564 1185 686
V/C Ratio(X) 1.16 0.31 0.00 1.22 0.45 0.91 0.58 0.84 0.75
Avail Cap(c_a), veh/h 396 407 0 768 1533 1189 564 1185 686
HCM Platoon Ratio 1.00 1.00 1.00 1.33 1.33 1.33 1.00 1.00 1.00
Upstream Filter(I) 1.00 1.00 0.00 0.09 0.09 0.09 0.40 0.40 0.40
Uniform Delay (d), s/veh 61.5 56.2 0.0 27.4 17.9 7.0 38.4 43.1 31.3
Incr Delay (d2), s/veh 98.2 0.4 0.0 102.3 0.0 1.2 1.8 3.1 3.0
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 13.0 2.3 0.0 51.1 7.2 42.1 10.8 18.4 20.3
LnGrp Delay(d),s/veh 159.7 56.6 0.0 129.7 18.0 8.1 40.2 46.1 34.3
LnGrp LOS F E F B A D D C
Approach Vol, veh/h 588 2714 1839
Approach Delay, s/veh 137.4 52.8 41.8
Approach LOS F D D
Timer 12345678
Assigned Phs 2 4 6
Phs Duration (G+Y+Rc), s 21.0 51.0 68.0
Change Period (Y+Rc), s 5.0 5.0 5.0
Max Green Setting (Gmax), s 16.0 46.0 63.0
Max Q Clear Time (g_c+I1), s 19.0 41.4 66.0
Green Ext Time (p_c), s 0.0 3.4 0.0
Intersection Summary
HCM 2010 Ctrl Delay 58.5
HCM 2010 LOS E
Notes
+&06LJQDOL]HG,QWHUVHFWLRQ&DSDFLW\$QDO\VLV
,1%2II5DPS,1%2Q5DPS 6510/29/2018
Cedar River Apartments 10/29/2018 2021 Phase 2 AM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Traffic Volume (vph) 18 394 0 0 1872 465 0 0 316 0 0 520
Future Volume (vph) 18 394 0 0 1872 465 0 0 316 0 0 520
Ideal Flow (vphpl) 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800
Total Lost time (s) 4.0 4.0 4.0 4.0 4.0 4.0
Lane Util. Factor 1.00 0.95 *0.70 1.00 1.00 1.00
Frt 1.00 1.00 1.00 0.85 0.86 0.86
Flt Protected 0.95 1.00 1.00 1.00 1.00 1.00
Satd. Flow (prot) 1621 3241 3582 1450 1476 1476
Flt Permitted 0.95 1.00 1.00 1.00 1.00 1.00
Satd. Flow (perm) 1621 3241 3582 1450 1476 1476
Peak-hour factor, PHF 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90
Adj. Flow (vph) 20 438 0 0 2080 517 0 0 351 0 0 578
RTOR Reduction (vph)000001480000010
Lane Group Flow (vph) 20 438 0 0 2080 369 0 0 351 0 0 568
Turn Type Prot NA NA Perm Free Perm
Protected Phases 5 2 6
Permitted Phases 6 Free 5
Actuated Green, G (s) 50.0 140.0 80.0 80.0 140.0 50.0
Effective Green, g (s) 51.0 140.0 81.0 81.0 140.0 51.0
Actuated g/C Ratio 0.36 1.00 0.58 0.58 1.00 0.36
Clearance Time (s) 5.0 5.0 5.0 5.0 5.0
Vehicle Extension (s) 3.0 3.0 3.0 3.0 3.0
Lane Grp Cap (vph) 590 3241 2072 838 1476 537
v/s Ratio Prot 0.01 0.14 c0.58
v/s Ratio Perm 0.25 0.24 c0.38
v/c Ratio 0.03 0.14 1.00 0.44 0.24 1.06
Uniform Delay, d1 28.6 0.0 29.5 16.7 0.0 44.5
Progression Factor 1.57 1.00 0.60 0.35 1.00 1.00
Incremental Delay, d2 0.0 0.0 17.7 1.3 0.4 54.9
Delay (s) 44.9 0.0 35.4 7.1 0.4 99.4
Level of Service D A D A A F
Approach Delay (s) 2.0 29.7 0.4 99.4
Approach LOS A C A F
Intersection Summary
HCM 2000 Control Delay 34.1 HCM 2000 Level of Service C
HCM 2000 Volume to Capacity ratio 1.02
Actuated Cycle Length (s) 140.0 Sum of lost time (s) 8.0
Intersection Capacity Utilization 78.8% ICU Level of Service D
Analysis Period (min) 15
Description: SR 169/I-405 NB On-Ramp
c Critical Lane Group
+&06LJQDOL]HG,QWHUVHFWLRQ6XPPDU\
65 6KDUL
V'ULYHZD\10/30/2018
Cedar River Apartments 10/29/2018 2021 Phase 2 AM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBU EBL EBT WBT WBR SBL SBR
Lane Configurations
Traffic Volume (veh/h) 58 37 713 2222 7 3 58
Future Volume (veh/h) 58 37 713 2222 7 3 58
Number 5 2 6 16 7 14
Initial Q (Qb), veh 0 0 0000
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1765 1765 1800 1765 1800
Adj Flow Rate, veh/h 41 792 2469 8 3 64
Adj No. of Lanes 134000
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222200
Cap, veh/h 63 3249 4416 14 4 94
Arrive On Green 0.08 1.00 1.00 1.00 0.07 0.06
Sat Flow, veh/h 1681 4235 5979 18 67 1422
Grp Volume(v), veh/h 41 792 1679 798 68 0
Grp Sat Flow(s),veh/h/ln 1681 1235 1235 1762 1510 0
Q Serve(g_s), s 3.3 0.0 0.0 0.0 6.2 0.0
Cycle Q Clear(g_c), s 3.3 0.0 0.0 0.0 6.2 0.0
Prop In Lane 1.00 0.01 0.04 0.94
Lane Grp Cap(c), veh/h 63 3249 3003 1427 100 0
V/C Ratio(X) 0.65 0.24 0.56 0.56 0.68 0.00
Avail Cap(c_a), veh/h 216 3249 3003 1427 183 0
HCM Platoon Ratio 2.00 2.00 2.00 2.00 1.00 1.00
Upstream Filter(I) 0.99 0.99 0.65 0.65 1.00 0.00
Uniform Delay (d), s/veh 63.8 0.0 0.0 0.0 64.4 0.0
Incr Delay (d2), s/veh 10.4 0.2 0.5 1.0 7.8 0.0
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 1.7 0.1 0.1 0.4 2.8 0.0
LnGrp Delay(d),s/veh 74.2 0.2 0.5 1.0 72.2 0.0
LnGrp LOS EAAAE
Approach Vol, veh/h 833 2477 68
Approach Delay, s/veh 3.8 0.7 72.2
Approach LOS A A E
Timer 12345678
Assigned Phs 2 4 5 6
Phs Duration (G+Y+Rc), s 126.7 13.3 9.3 117.4
Change Period (Y+Rc), s 5.0 5.0 5.0 5.0
Max Green Setting (Gmax), s 114.0 16.0 17.0 92.0
Max Q Clear Time (g_c+I1), s 2.0 8.2 5.3 2.0
Green Ext Time (p_c), s 47.2 0.1 0.1 43.6
Intersection Summary
HCM 2010 Ctrl Delay 2.9
HCM 2010 LOS A
Notes
+&06LJQDOL]HG,QWHUVHFWLRQ6XPPDU\
&HGDU5LYHU3DUN'U 6510/30/2018
Cedar River Apartments 10/29/2018 2021 Phase 2 AM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBT EBR WBL WBT NBL NBR
Lane Configurations
Traffic Volume (veh/h) 660 99 13 2085 142 6
Future Volume (veh/h) 660 99 13 2085 142 6
Number 21216318
Initial Q (Qb), veh 0 0 0 0 0 0
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1800 1765 1765 1765 1765
Adj Flow Rate, veh/h 733 110 14 2317 158 7
Adj No. of Lanes 301311
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222222
Cap, veh/h 2540 379 28 3375 324 289
Arrive On Green 1.00 1.00 0.02 0.75 0.19 0.19
Sat Flow, veh/h 4133 537 1681 4765 1681 1500
Grp Volume(v), veh/h 501 342 14 2317 158 7
Grp Sat Flow(s),veh/h/ln 1235 1670 1681 1500 1681 1500
Q Serve(g_s), s 0.0 0.0 1.2 37.1 11.7 0.5
Cycle Q Clear(g_c), s 0.0 0.0 1.2 37.1 11.7 0.5
Prop In Lane 0.32 1.00 1.00 1.00
Lane Grp Cap(c), veh/h 1741 1177 28 3375 324 289
V/C Ratio(X) 0.29 0.29 0.50 0.69 0.49 0.02
Avail Cap(c_a), veh/h 1741 1177 60 3375 324 289
HCM Platoon Ratio 2.00 2.00 1.00 1.00 1.00 1.00
Upstream Filter(I) 0.97 0.97 1.00 1.00 1.00 1.00
Uniform Delay (d), s/veh 0.0 0.0 68.3 9.0 50.3 45.8
Incr Delay (d2), s/veh 0.4 0.6 13.2 1.2 5.2 0.2
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 0.1 0.2 0.6 15.6 5.9 0.2
LnGrp Delay(d),s/veh 0.4 0.6 81.5 10.2 55.5 46.0
LnGrp LOS A A F B E D
Approach Vol, veh/h 843 2331 165
Approach Delay, s/veh 0.5 10.6 55.1
Approach LOS A B E
Timer 12345678
Assigned Phs 1 2 6 8
Phs Duration (G+Y+Rc), s 6.3 102.7 109.0 31.0
Change Period (Y+Rc), s 5.0 5.0 5.0 5.0
Max Green Setting (Gmax), s 4.0 95.0 104.0 26.0
Max Q Clear Time (g_c+I1), s 3.2 2.0 39.1 13.7
Green Ext Time (p_c), s 0.0 42.1 36.0 0.4
Intersection Summary
HCM 2010 Ctrl Delay 10.2
HCM 2010 LOS B
+&07:6&
6LWH(DVW$FFHVV 6510/29/2018
Cedar River Apartments 10/29/2018 2021 Phase 2 AM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Intersection
Int Delay, s/veh 0.1
Movement EBT EBR WBL WBT NBL NBR
Lane Configurations
Traffic Vol, veh/h 661 5 8 2103 0 20
Future Vol, veh/h 661 5 8 2103 0 20
Conflicting Peds, #/hr 000000
Sign Control Free Free Free Free Stop Stop
RT Channelized - None - None - None
Storage Length - 0 150 - 150 0
Veh in Median Storage, # 0 - - 0 0 -
Grade, % 0 - - 0 0 -
Peak Hour Factor 90 90 90 90 90 90
Heavy Vehicles, %222222
Mvmt Flow 734 6 9 2337 0 22
Major/Minor Major1 Major2 Minor1
Conflicting Flow All 0 0 734 0 1686 367
Stage 1 - - - - 734 -
Stage 2 - - - - 952 -
Critical Hdwy - - 4.14 - 6.29 6.94
Critical Hdwy Stg 1 - - - - 5.84 -
Critical Hdwy Stg 2 - - - - 6.04 -
Follow-up Hdwy - - 2.22 - 3.67 3.32
Pot Cap-1 Maneuver - - 867 - 108 630
Stage 1 - - - - 424 -
Stage 2 - - - - 310 -
Platoon blocked, % - - -
Mov Cap-1 Maneuver - - 867 - 107 630
Mov Cap-2 Maneuver - - - - 107 -
Stage 1 - - - - 424 -
Stage 2 - - - - 307 -
Approach EB WB NB
HCM Control Delay, s 0 0 10.9
HCM LOS B
Minor Lane/Major Mvmt NBLn1NBLn2 EBT EBR WBL WBT
Capacity (veh/h) - 630 - - 867 -
HCM Lane V/C Ratio - 0.035 - - 0.01 -
HCM Control Delay (s) 0 10.9 - - 9.2 -
HCM Lane LOS A B - - A -
HCM 95th %tile Q(veh) - 0.1 - - 0 -
+&06LJQDOL]HG,QWHUVHFWLRQ6XPPDU\
,6%2Q5DPS6XQVHW%OYG %URQVRQ:D\6510/30/2018
Cedar River Apartments 10/29/2018 2021 Phase 3 AM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Traffic Volume (veh/h) 419 120 50 857 628 988000323905466
Future Volume (veh/h) 419 120 50 857 628 988 0 0 0 323 905 466
Number 5 2 12 1 6 16 7 4 14
Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1765 1800 1765 1765 1765 1765 1765 1765
Adj Flow Rate, veh/h 466 133 0 952 698 1098 359 1006 518
Adj No. of Lanes 220121 121
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222222 222
Cap, veh/h 396 407 0 768 1533 1189 564 1185 686
Arrive On Green 0.12 0.12 0.00 0.61 0.61 0.61 0.34 0.34 0.34
Sat Flow, veh/h 3261 3441 0 1681 3353 1500 1681 3529 1500
Grp Volume(v), veh/h 466 133 0 952 698 1098 359 1006 518
Grp Sat Flow(s),veh/h/ln 1630 1676 0 1681 1676 1500 1681 1765 1500
Q Serve(g_s), s 17.0 5.1 0.0 64.0 15.8 64.0 25.3 37.1 40.1
Cycle Q Clear(g_c), s 17.0 5.1 0.0 64.0 15.8 64.0 25.3 37.1 40.1
Prop In Lane 1.00 0.00 1.00 1.00 1.00 1.00
Lane Grp Cap(c), veh/h 396 407 0 768 1533 1189 564 1185 686
V/C Ratio(X) 1.18 0.33 0.00 1.24 0.46 0.92 0.64 0.85 0.76
Avail Cap(c_a), veh/h 396 407 0 768 1533 1189 564 1185 686
HCM Platoon Ratio 1.00 1.00 1.00 1.33 1.33 1.33 1.00 1.00 1.00
Upstream Filter(I) 1.00 1.00 0.00 0.09 0.09 0.09 0.40 0.40 0.40
Uniform Delay (d), s/veh 61.5 56.3 0.0 27.4 18.0 7.0 39.3 43.2 31.5
Incr Delay (d2), s/veh 103.0 0.5 0.0 108.7 0.0 1.4 2.2 3.2 3.1
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 13.3 2.4 0.0 52.5 7.3 42.8 12.0 18.6 20.6
LnGrp Delay(d),s/veh 164.5 56.7 0.0 136.1 18.0 8.3 41.5 46.4 34.6
LnGrp LOS F E F B A D D C
Approach Vol, veh/h 599 2748 1883
Approach Delay, s/veh 140.6 55.1 42.2
Approach LOS F E D
Timer 12345678
Assigned Phs 2 4 6
Phs Duration (G+Y+Rc), s 21.0 51.0 68.0
Change Period (Y+Rc), s 5.0 5.0 5.0
Max Green Setting (Gmax), s 16.0 46.0 63.0
Max Q Clear Time (g_c+I1), s 19.0 42.1 66.0
Green Ext Time (p_c), s 0.0 3.0 0.0
Intersection Summary
HCM 2010 Ctrl Delay 60.2
HCM 2010 LOS E
Notes
+&06LJQDOL]HG,QWHUVHFWLRQ&DSDFLW\$QDO\VLV
,1%2II5DPS,1%2Q5DPS 6510/29/2018
Cedar River Apartments 10/29/2018 2021 Phase 3 AM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Traffic Volume (vph) 18 426 0 0 1897 472 0 0 329 0 0 525
Future Volume (vph) 18 426 0 0 1897 472 0 0 329 0 0 525
Ideal Flow (vphpl) 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800
Total Lost time (s) 4.0 4.0 4.0 4.0 4.0 4.0
Lane Util. Factor 1.00 0.95 *0.70 1.00 1.00 1.00
Frt 1.00 1.00 1.00 0.85 0.86 0.86
Flt Protected 0.95 1.00 1.00 1.00 1.00 1.00
Satd. Flow (prot) 1621 3241 3582 1450 1476 1476
Flt Permitted 0.95 1.00 1.00 1.00 1.00 1.00
Satd. Flow (perm) 1621 3241 3582 1450 1476 1476
Peak-hour factor, PHF 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90
Adj. Flow (vph) 20 473 0 0 2108 524 0 0 366 0 0 583
RTOR Reduction (vph)000001480000010
Lane Group Flow (vph) 20 473 0 0 2108 377 0 0 366 0 0 573
Turn Type Prot NA NA Perm Free Perm
Protected Phases 5 2 6
Permitted Phases 6 Free 5
Actuated Green, G (s) 50.0 140.0 80.0 80.0 140.0 50.0
Effective Green, g (s) 51.0 140.0 81.0 81.0 140.0 51.0
Actuated g/C Ratio 0.36 1.00 0.58 0.58 1.00 0.36
Clearance Time (s) 5.0 5.0 5.0 5.0 5.0
Vehicle Extension (s) 3.0 3.0 3.0 3.0 3.0
Lane Grp Cap (vph) 590 3241 2072 838 1476 537
v/s Ratio Prot 0.01 0.15 c0.59
v/s Ratio Perm 0.26 0.25 c0.39
v/c Ratio 0.03 0.15 1.02 0.45 0.25 1.07
Uniform Delay, d1 28.6 0.0 29.5 16.8 0.0 44.5
Progression Factor 1.61 1.00 0.61 0.38 1.00 1.00
Incremental Delay, d2 0.0 0.0 21.2 1.3 0.4 57.8
Delay (s) 46.1 0.0 39.2 7.7 0.4 102.3
Level of Service D A D A A F
Approach Delay (s) 1.9 32.9 0.4 102.3
Approach LOS A C A F
Intersection Summary
HCM 2000 Control Delay 36.2 HCM 2000 Level of Service D
HCM 2000 Volume to Capacity ratio 1.04
Actuated Cycle Length (s) 140.0 Sum of lost time (s) 8.0
Intersection Capacity Utilization 79.7% ICU Level of Service D
Analysis Period (min) 15
Description: SR 169/I-405 NB On-Ramp
c Critical Lane Group
+&06LJQDOL]HG,QWHUVHFWLRQ6XPPDU\
65 6KDUL
V'ULYHZD\10/30/2018
Cedar River Apartments 10/29/2018 2021 Phase 3 AM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBU EBL EBT WBT WBR SBL SBR
Lane Configurations
Traffic Volume (veh/h) 58 37 758 2252 7 3 58
Future Volume (veh/h) 58 37 758 2252 7 3 58
Number 5 2 6 16 7 14
Initial Q (Qb), veh 0 0 0000
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1765 1765 1800 1765 1800
Adj Flow Rate, veh/h 41 842 2502 8 3 64
Adj No. of Lanes 134000
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222200
Cap, veh/h 63 3249 4416 14 4 94
Arrive On Green 0.08 1.00 1.00 1.00 0.07 0.06
Sat Flow, veh/h 1681 4235 5980 17 67 1422
Grp Volume(v), veh/h 41 842 1701 809 68 0
Grp Sat Flow(s),veh/h/ln 1681 1235 1235 1762 1510 0
Q Serve(g_s), s 3.3 0.0 0.0 0.0 6.2 0.0
Cycle Q Clear(g_c), s 3.3 0.0 0.0 0.0 6.2 0.0
Prop In Lane 1.00 0.01 0.04 0.94
Lane Grp Cap(c), veh/h 63 3249 3003 1427 100 0
V/C Ratio(X) 0.65 0.26 0.57 0.57 0.68 0.00
Avail Cap(c_a), veh/h 204 3249 3003 1427 183 0
HCM Platoon Ratio 2.00 2.00 2.00 2.00 1.00 1.00
Upstream Filter(I) 0.99 0.99 0.64 0.64 1.00 0.00
Uniform Delay (d), s/veh 63.8 0.0 0.0 0.0 64.4 0.0
Incr Delay (d2), s/veh 10.4 0.2 0.5 1.0 7.8 0.0
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 1.7 0.1 0.1 0.4 2.8 0.0
LnGrp Delay(d),s/veh 74.2 0.2 0.5 1.0 72.2 0.0
LnGrp LOS EAAAE
Approach Vol, veh/h 883 2510 68
Approach Delay, s/veh 3.6 0.7 72.2
Approach LOS A A E
Timer 12345678
Assigned Phs 2 4 5 6
Phs Duration (G+Y+Rc), s 126.7 13.3 9.3 117.4
Change Period (Y+Rc), s 5.0 5.0 5.0 5.0
Max Green Setting (Gmax), s 114.0 16.0 16.0 93.0
Max Q Clear Time (g_c+I1), s 2.0 8.2 5.3 2.0
Green Ext Time (p_c), s 50.1 0.1 0.1 46.2
Intersection Summary
HCM 2010 Ctrl Delay 2.8
HCM 2010 LOS A
Notes
+&06LJQDOL]HG,QWHUVHFWLRQ6XPPDU\
&HGDU5LYHU3DUN'U 6510/30/2018
Cedar River Apartments 10/29/2018 2021 Phase 3 AM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBT EBR WBL WBT NBL NBR
Lane Configurations
Traffic Volume (veh/h) 682 123 16 2106 153 7
Future Volume (veh/h) 682 123 16 2106 153 7
Number 21216318
Initial Q (Qb), veh 0 0 0 0 0 0
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1800 1765 1765 1765 1765
Adj Flow Rate, veh/h 758 137 18 2340 170 8
Adj No. of Lanes 301311
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222222
Cap, veh/h 2429 436 33 3343 336 300
Arrive On Green 1.00 1.00 0.02 0.74 0.20 0.20
Sat Flow, veh/h 4026 628 1681 4765 1681 1500
Grp Volume(v), veh/h 534 361 18 2340 170 8
Grp Sat Flow(s),veh/h/ln 1235 1654 1681 1500 1681 1500
Q Serve(g_s), s 0.0 0.0 1.5 39.0 12.6 0.6
Cycle Q Clear(g_c), s 0.0 0.0 1.5 39.0 12.6 0.6
Prop In Lane 0.38 1.00 1.00 1.00
Lane Grp Cap(c), veh/h 1716 1149 33 3343 336 300
V/C Ratio(X) 0.31 0.31 0.54 0.70 0.51 0.03
Avail Cap(c_a), veh/h 1716 1149 72 3343 336 300
HCM Platoon Ratio 2.00 2.00 1.00 1.00 1.00 1.00
Upstream Filter(I) 0.97 0.97 1.00 1.00 1.00 1.00
Uniform Delay (d), s/veh 0.0 0.0 68.0 9.6 49.8 45.0
Incr Delay (d2), s/veh 0.5 0.7 13.2 1.2 5.4 0.2
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 0.1 0.2 0.8 16.2 6.4 0.3
LnGrp Delay(d),s/veh 0.5 0.7 81.2 10.9 55.2 45.2
LnGrp LOS A A F B E D
Approach Vol, veh/h 895 2358 178
Approach Delay, s/veh 0.6 11.4 54.7
Approach LOS A B D
Timer 12345678
Assigned Phs 1 2 6 8
Phs Duration (G+Y+Rc), s 6.8 101.2 108.0 32.0
Change Period (Y+Rc), s 5.0 5.0 5.0 5.0
Max Green Setting (Gmax), s 5.0 93.0 103.0 27.0
Max Q Clear Time (g_c+I1), s 3.5 2.0 41.0 14.6
Green Ext Time (p_c), s 0.0 43.8 36.5 0.5
Intersection Summary
HCM 2010 Ctrl Delay 10.8
HCM 2010 LOS B
+&07:6&
6LWH(DVW$FFHVV 6510/29/2018
Cedar River Apartments 10/29/2018 2021 Phase 3 AM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Intersection
Int Delay, s/veh 0.2
Movement EBT EBR WBL WBT NBL NBR
Lane Configurations
Traffic Vol, veh/h 669 21 18 2127 0 22
Future Vol, veh/h 669 21 18 2127 0 22
Conflicting Peds, #/hr 000000
Sign Control Free Free Free Free Stop Stop
RT Channelized - None - None - None
Storage Length - 0 150 - 150 0
Veh in Median Storage, # 0 - - 0 0 -
Grade, % 0 - - 0 0 -
Peak Hour Factor 90 90 90 90 90 90
Heavy Vehicles, %222222
Mvmt Flow 743 23 20 2363 0 24
Major/Minor Major1 Major2 Minor1
Conflicting Flow All 0 0 743 0 1728 372
Stage 1 - - - - 743 -
Stage 2 - - - - 985 -
Critical Hdwy - - 4.14 - 6.29 6.94
Critical Hdwy Stg 1 - - - - 5.84 -
Critical Hdwy Stg 2 - - - - 6.04 -
Follow-up Hdwy - - 2.22 - 3.67 3.32
Pot Cap-1 Maneuver - - 860 - 102 625
Stage 1 - - - - 419 -
Stage 2 - - - - 298 -
Platoon blocked, % - - -
Mov Cap-1 Maneuver - - 860 - 100 625
Mov Cap-2 Maneuver - - - - 100 -
Stage 1 - - - - 419 -
Stage 2 - - - - 291 -
Approach EB WB NB
HCM Control Delay, s 0 0.1 11
HCM LOS B
Minor Lane/Major Mvmt NBLn1NBLn2 EBT EBR WBL WBT
Capacity (veh/h) - 625 - - 860 -
HCM Lane V/C Ratio - 0.039 - - 0.023 -
HCM Control Delay (s) 0 11 - - 9.3 -
HCM Lane LOS A B - - A -
HCM 95th %tile Q(veh) - 0.1 - - 0.1 -
+&06LJQDOL]HG,QWHUVHFWLRQ6XPPDU\
,6%2Q5DPS6XQVHW%OYG %URQVRQ:D\6510/30/2018
Cedar River Apartments 10/30/2018 2021 Phase 3 AM Peak -- with dual WBL Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Traffic Volume (veh/h) 419 120 50 857 628 988000323905466
Future Volume (veh/h) 419 120 50 857 628 988 0 0 0 323 905 466
Number 5 2 12 1 6 16 7 4 14
Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1765 1800 1765 1765 1765 1765 1765 1765
Adj Flow Rate, veh/h 466 133 0 952 698 1098 359 1006 518
Adj No. of Lanes 220211 121
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222222 222
Cap, veh/h 396 407 0 1537 807 1189 564 1185 686
Arrive On Green 0.12 0.12 0.00 0.61 0.61 0.61 0.34 0.34 0.34
Sat Flow, veh/h 3261 3441 0 3361 1765 1500 1681 3529 1500
Grp Volume(v), veh/h 466 133 0 952 698 1098 359 1006 518
Grp Sat Flow(s),veh/h/ln 1630 1676 0 1681 1765 1500 1681 1765 1500
Q Serve(g_s), s 17.0 5.1 0.0 24.9 45.8 64.0 25.3 37.1 40.1
Cycle Q Clear(g_c), s 17.0 5.1 0.0 24.9 45.8 64.0 25.3 37.1 40.1
Prop In Lane 1.00 0.00 1.00 1.00 1.00 1.00
Lane Grp Cap(c), veh/h 396 407 0 1537 807 1189 564 1185 686
V/C Ratio(X) 1.18 0.33 0.00 0.62 0.87 0.92 0.64 0.85 0.76
Avail Cap(c_a), veh/h 396 407 0 1537 807 1189 564 1185 686
HCM Platoon Ratio 1.00 1.00 1.00 1.33 1.33 1.33 1.00 1.00 1.00
Upstream Filter(I) 1.00 1.00 0.00 0.09 0.09 0.09 0.40 0.40 0.40
Uniform Delay (d), s/veh 61.5 56.3 0.0 19.8 23.9 7.0 39.3 43.2 31.5
Incr Delay (d2), s/veh 103.0 0.5 0.0 0.1 1.0 1.4 2.2 3.2 3.1
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 13.3 2.4 0.0 11.5 22.2 42.8 12.0 18.6 20.6
LnGrp Delay(d),s/veh 164.5 56.7 0.0 19.9 24.9 8.3 41.5 46.4 34.6
LnGrp LOS F E B C A D D C
Approach Vol, veh/h 599 2748 1883
Approach Delay, s/veh 140.6 16.5 42.2
Approach LOS F B D
Timer 12345678
Assigned Phs 2 4 6
Phs Duration (G+Y+Rc), s 21.0 51.0 68.0
Change Period (Y+Rc), s 5.0 5.0 5.0
Max Green Setting (Gmax), s 16.0 46.0 63.0
Max Q Clear Time (g_c+I1), s 19.0 42.1 66.0
Green Ext Time (p_c), s 0.0 3.0 0.0
Intersection Summary
HCM 2010 Ctrl Delay 40.0
HCM 2010 LOS D
Notes
+&06LJQDOL]HG,QWHUVHFWLRQ6XPPDU\
,6%2Q5DPS6XQVHW%OYG %URQVRQ:D\6510/29/2018
Cedar River Apartments 10/26/2018 2017 existing PM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Traffic Volume (veh/h) 673 520 65 334 236 7700001145 745 638
Future Volume (veh/h) 673 520 65 334 236 770 0 0 0 1145 745 638
Number 5 2 12 1 6 16 7 4 14
Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1765 1800 1765 1765 1765 1765 1765 1765
Adj Flow Rate, veh/h 748 578 0 371 262 856 1272 828 709
Adj No. of Lanes 220211 211
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222222 222
Cap, veh/h 582 599 0 624 328 1104 1849 971 1093
Arrive On Green 0.18 0.18 0.00 0.06 0.06 0.06 0.55 0.55 0.55
Sat Flow, veh/h 3261 3441 0 3361 1765 1500 3361 1765 1500
Grp Volume(v), veh/h 748 578 0 371 262 856 1272 828 709
Grp Sat Flow(s),veh/h/ln 1630 1676 0 1681 1765 1500 1681 1765 1500
Q Serve(g_s), s 25.0 24.0 0.0 15.1 20.5 26.0 38.4 55.7 34.1
Cycle Q Clear(g_c), s 25.0 24.0 0.0 15.1 20.5 26.0 38.4 55.7 34.1
Prop In Lane 1.00 0.00 1.00 1.00 1.00 1.00
Lane Grp Cap(c), veh/h 582 599 0 624 328 1104 1849 971 1093
V/C Ratio(X) 1.28 0.97 0.00 0.59 0.80 0.78 0.69 0.85 0.65
Avail Cap(c_a), veh/h 582 599 0 624 328 1104 1849 971 1093
HCM Platoon Ratio 1.00 1.00 1.00 0.33 0.33 0.33 1.00 1.00 1.00
Upstream Filter(I) 1.00 1.00 0.00 0.61 0.61 0.61 0.40 0.40 0.40
Uniform Delay (d), s/veh 57.5 57.1 0.0 60.6 63.1 9.6 22.8 26.7 9.8
Incr Delay (d2), s/veh 140.8 28.2 0.0 0.9 8.4 2.2 0.8 4.0 1.2
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 22.6 13.4 0.0 7.1 10.8 33.9 17.9 28.0 23.6
LnGrp Delay(d),s/veh 198.3 85.3 0.0 61.5 71.5 11.8 23.7 30.7 11.0
LnGrp LOS F F E E B C C B
Approach Vol, veh/h 1326 1489 2809
Approach Delay, s/veh 149.0 34.7 22.5
Approach LOS F C C
Timer 12345678
Assigned Phs 2 4 6
Phs Duration (G+Y+Rc), s 29.0 81.0 30.0
Change Period (Y+Rc), s 5.0 5.0 5.0
Max Green Setting (Gmax), s 24.0 76.0 25.0
Max Q Clear Time (g_c+I1), s 27.0 57.7 28.0
Green Ext Time (p_c), s 0.0 14.3 0.0
Intersection Summary
HCM 2010 Ctrl Delay 55.6
HCM 2010 LOS E
Notes
+&06LJQDOL]HG,QWHUVHFWLRQ&DSDFLW\$QDO\VLV
,1%2II5DPS,1%2Q5DPS 6510/29/2018
Cedar River Apartments 10/26/2018 2017 existing PM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Traffic Volume (vph) 61 1604 0 0 704 246 0 0 771 0 0 672
Future Volume (vph) 61 1604 0 0 704 246 0 0 771 0 0 672
Ideal Flow (vphpl) 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800
Total Lost time (s) 4.0 4.0 4.0 4.0 4.0 4.0
Lane Util. Factor 1.00 0.95 *0.70 1.00 1.00 1.00
Frt 1.00 1.00 1.00 0.85 0.86 0.86
Flt Protected 0.95 1.00 1.00 1.00 1.00 1.00
Satd. Flow (prot) 1621 3241 3582 1450 1476 1476
Flt Permitted 0.95 1.00 1.00 1.00 1.00 1.00
Satd. Flow (perm) 1621 3241 3582 1450 1476 1476
Peak-hour factor, PHF 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90
Adj. Flow (vph) 68 1782 0 0 782 273 0 0 857 0 0 747
RTOR Reduction (vph)000001780000014
Lane Group Flow (vph) 68 1782 0 0 782 95 0 0 857 0 0 733
Turn Type Prot NA NA Perm Free Perm
Protected Phases 5 2 6
Permitted Phases 6 Free 5
Actuated Green, G (s) 82.3 140.0 47.7 47.7 140.0 82.3
Effective Green, g (s) 83.3 140.0 48.7 48.7 140.0 83.3
Actuated g/C Ratio 0.59 1.00 0.35 0.35 1.00 0.59
Clearance Time (s) 5.0 5.0 5.0 5.0 5.0
Vehicle Extension (s) 3.0 3.0 3.0 3.0 3.0
Lane Grp Cap (vph) 964 3241 1246 504 1476 878
v/s Ratio Prot 0.04 0.55 0.22
v/s Ratio Perm 0.07 c0.58 c0.50
v/c Ratio 0.07 0.55 0.63 0.19 0.58 0.83
Uniform Delay, d1 12.0 0.0 38.1 31.9 0.0 22.8
Progression Factor 1.31 1.00 0.85 0.41 1.00 1.00
Incremental Delay, d2 0.0 0.1 2.3 0.8 1.7 6.9
Delay (s) 15.7 0.1 34.8 13.8 1.7 29.7
Level of Service B A C B A C
Approach Delay (s) 0.6 29.4 1.7 29.7
Approach LOS A C A C
Intersection Summary
HCM 2000 Control Delay 12.4 HCM 2000 Level of Service B
HCM 2000 Volume to Capacity ratio 0.76
Actuated Cycle Length (s) 140.0 Sum of lost time (s) 8.0
Intersection Capacity Utilization 64.9% ICU Level of Service C
Analysis Period (min) 15
Description: SR 169/I-405 NB On-Ramp
c Critical Lane Group
+&06LJQDOL]HG,QWHUVHFWLRQ6XPPDU\
65 6KDUL
V'ULYHZD\10/29/2018
Cedar River Apartments 10/26/2018 2017 existing PM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBU EBL EBT WBT WBR SBL SBR
Lane Configurations
Traffic Volume (veh/h) 15 41 2118 935 13 4 31
Future Volume (veh/h) 15 41 2118 935 13 4 31
Number 5 2 6 16 7 14
Initial Q (Qb), veh 0 0 0000
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1765 1765 1800 1765 1800
Adj Flow Rate, veh/h 46 2353 1039 14 4 34
Adj No. of Lanes 134000
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222200
Cap, veh/h 69 3320 4448 60 7 62
Arrive On Green 0.08 1.00 1.00 1.00 0.05 0.04
Sat Flow, veh/h 1681 4235 5915 72 156 1327
Grp Volume(v), veh/h 46 2353 715 338 39 0
Grp Sat Flow(s),veh/h/ln 1681 1235 1235 1752 1523 0
Q Serve(g_s), s 3.7 0.0 0.0 0.0 3.5 0.0
Cycle Q Clear(g_c), s 3.7 0.0 0.0 0.0 3.5 0.0
Prop In Lane 1.00 0.04 0.10 0.87
Lane Grp Cap(c), veh/h 69 3320 3061 1447 71 0
V/C Ratio(X) 0.66 0.71 0.23 0.23 0.55 0.00
Avail Cap(c_a), veh/h 132 3320 3061 1447 185 0
HCM Platoon Ratio 2.00 2.00 1.33 1.33 1.00 1.00
Upstream Filter(I) 0.81 0.81 0.97 0.97 1.00 0.00
Uniform Delay (d), s/veh 63.3 0.0 0.0 0.0 65.7 0.0
Incr Delay (d2), s/veh 8.4 1.1 0.2 0.4 6.3 0.0
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 1.9 0.3 0.0 0.1 1.6 0.0
LnGrp Delay(d),s/veh 71.7 1.1 0.2 0.4 72.0 0.0
LnGrp LOS EAAAE
Approach Vol, veh/h 2399 1053 39
Approach Delay, s/veh 2.4 0.2 72.0
Approach LOS A A E
Timer 12345678
Assigned Phs 2 4 5 6
Phs Duration (G+Y+Rc), s 129.4 10.6 9.8 119.6
Change Period (Y+Rc), s 5.0 5.0 5.0 5.0
Max Green Setting (Gmax), s 114.0 16.0 10.0 99.0
Max Q Clear Time (g_c+I1), s 2.0 5.5 5.7 2.0
Green Ext Time (p_c), s 57.5 0.1 0.0 53.8
Intersection Summary
HCM 2010 Ctrl Delay 2.5
HCM 2010 LOS A
Notes
+&06LJQDOL]HG,QWHUVHFWLRQ6XPPDU\
&HGDU5LYHU3DUN'U 6510/29/2018
Cedar River Apartments 10/26/2018 2017 existing PM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBT EBR WBL WBT NBL NBR
Lane Configurations
Traffic Volume (veh/h) 2082 36 12 910 38 66
Future Volume (veh/h) 2082 36 12 910 38 66
Number 21216318
Initial Q (Qb), veh 0 0 0 0 0 0
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1800 1765 1765 1765 1765
Adj Flow Rate, veh/h 2313 40 13 1011 42 73
Adj No. of Lanes 301311
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222222
Cap, veh/h 3225 56 27 3696 204 182
Arrive On Green 1.00 1.00 0.02 0.82 0.12 0.12
Sat Flow, veh/h 4680 72 1681 4765 1681 1500
Grp Volume(v), veh/h 1375 978 13 1011 42 73
Grp Sat Flow(s),veh/h/ln 1235 1752 1681 1500 1681 1500
Q Serve(g_s), s 0.0 0.0 1.1 7.2 3.2 6.3
Cycle Q Clear(g_c), s 0.0 0.0 1.1 7.2 3.2 6.3
Prop In Lane 0.04 1.00 1.00 1.00
Lane Grp Cap(c), veh/h 1920 1361 27 3696 204 182
V/C Ratio(X) 0.72 0.72 0.49 0.27 0.21 0.40
Avail Cap(c_a), veh/h 1920 1361 48 3696 204 182
HCM Platoon Ratio 2.00 2.00 1.00 1.00 1.00 1.00
Upstream Filter(I) 0.60 0.60 1.00 1.00 1.00 1.00
Uniform Delay (d), s/veh 0.0 0.0 68.3 2.9 55.4 56.8
Incr Delay (d2), s/veh 1.4 2.0 13.1 0.2 2.3 6.5
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 0.4 0.8 0.6 3.0 1.6 2.9
LnGrp Delay(d),s/veh 1.4 2.0 81.5 3.1 57.7 63.3
LnGrp LOS A A F A E E
Approach Vol, veh/h 2353 1024 115
Approach Delay, s/veh 1.7 4.1 61.2
Approach LOS A A E
Timer 12345678
Assigned Phs 1 2 6 8
Phs Duration (G+Y+Rc), s 6.2 112.8 119.0 21.0
Change Period (Y+Rc), s 5.0 5.0 5.0 5.0
Max Green Setting (Gmax), s 3.0 106.0 114.0 16.0
Max Q Clear Time (g_c+I1), s 3.1 2.0 9.2 8.3
Green Ext Time (p_c), s 0.0 49.3 49.5 0.2
Intersection Summary
HCM 2010 Ctrl Delay 4.3
HCM 2010 LOS A
+&06LJQDOL]HG,QWHUVHFWLRQ6XPPDU\
,6%2Q5DPS6XQVHW%OYG %URQVRQ:D\6510/29/2018
Cedar River Apartments 10/29/2018 2021 without Project PM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Traffic Volume (veh/h) 700 541 68 348 246 8010001191 775 664
Future Volume (veh/h) 700 541 68 348 246 801 0 0 0 1191 775 664
Number 5 2 12 1 6 16 7 4 14
Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1765 1800 1765 1765 1765 1765 1765 1765
Adj Flow Rate, veh/h 778 601 0 387 273 890 1323 861 738
Adj No. of Lanes 220121 211
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222222 222
Cap, veh/h 606 623 0 300 599 1093 1849 971 1104
Arrive On Green 0.19 0.19 0.00 0.06 0.06 0.06 0.55 0.55 0.55
Sat Flow, veh/h 3261 3441 0 1681 3353 1500 3361 1765 1500
Grp Volume(v), veh/h 778 601 0 387 273 890 1323 861 738
Grp Sat Flow(s),veh/h/ln 1630 1676 0 1681 1676 1500 1681 1765 1500
Q Serve(g_s), s 26.0 24.9 0.0 25.0 11.0 25.0 40.9 60.0 35.8
Cycle Q Clear(g_c), s 26.0 24.9 0.0 25.0 11.0 25.0 40.9 60.0 35.8
Prop In Lane 1.00 0.00 1.00 1.00 1.00 1.00
Lane Grp Cap(c), veh/h 606 623 0 300 599 1093 1849 971 1104
V/C Ratio(X) 1.28 0.97 0.00 1.29 0.46 0.81 0.72 0.89 0.67
Avail Cap(c_a), veh/h 606 623 0 300 599 1093 1849 971 1104
HCM Platoon Ratio 1.00 1.00 1.00 0.33 0.33 0.33 1.00 1.00 1.00
Upstream Filter(I) 1.00 1.00 0.00 0.56 0.56 0.56 0.40 0.40 0.40
Uniform Delay (d), s/veh 57.0 56.6 0.0 65.9 59.3 9.8 23.4 27.7 9.6
Incr Delay (d2), s/veh 140.4 27.5 0.0 143.8 0.3 2.8 1.0 5.2 1.3
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 23.5 13.9 0.0 23.6 5.1 35.4 19.2 30.6 25.6
LnGrp Delay(d),s/veh 197.4 84.0 0.0 209.6 59.6 12.6 24.3 32.9 10.9
LnGrp LOS F F F E B C C B
Approach Vol, veh/h 1379 1550 2922
Approach Delay, s/veh 148.0 70.1 23.5
Approach LOS F E C
Timer 12345678
Assigned Phs 2 4 6
Phs Duration (G+Y+Rc), s 30.0 81.0 29.0
Change Period (Y+Rc), s 5.0 5.0 5.0
Max Green Setting (Gmax), s 25.0 76.0 24.0
Max Q Clear Time (g_c+I1), s 28.0 62.0 27.0
Green Ext Time (p_c), s 0.0 11.7 0.0
Intersection Summary
HCM 2010 Ctrl Delay 65.2
HCM 2010 LOS E
Notes
+&06LJQDOL]HG,QWHUVHFWLRQ&DSDFLW\$QDO\VLV
,1%2II5DPS,1%2Q5DPS 6510/29/2018
Cedar River Apartments 10/29/2018 2021 without Project PM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Traffic Volume (vph) 63 1669 0 0 733 256 0 0 802 0 0 699
Future Volume (vph) 63 1669 0 0 733 256 0 0 802 0 0 699
Ideal Flow (vphpl) 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800
Total Lost time (s) 4.0 4.0 4.0 4.0 4.0 4.0
Lane Util. Factor 1.00 0.95 *0.70 1.00 1.00 1.00
Frt 1.00 1.00 1.00 0.85 0.86 0.86
Flt Protected 0.95 1.00 1.00 1.00 1.00 1.00
Satd. Flow (prot) 1621 3241 3582 1450 1476 1476
Flt Permitted 0.95 1.00 1.00 1.00 1.00 1.00
Satd. Flow (perm) 1621 3241 3582 1450 1476 1476
Peak-hour factor, PHF 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90
Adj. Flow (vph) 70 1854 0 0 814 284 0 0 891 0 0 777
RTOR Reduction (vph)000001880000012
Lane Group Flow (vph) 70 1854 0 0 814 96 0 0 891 0 0 765
Turn Type Prot NA NA Perm Free Over
Protected Phases 5 2 6 5
Permitted Phases 6 Free
Actuated Green, G (s) 83.8 140.0 46.2 46.2 140.0 83.8
Effective Green, g (s) 84.8 140.0 47.2 47.2 140.0 84.8
Actuated g/C Ratio 0.61 1.00 0.34 0.34 1.00 0.61
Clearance Time (s) 5.0 5.0 5.0 5.0 5.0
Vehicle Extension (s) 3.0 3.0 3.0 3.0 3.0
Lane Grp Cap (vph) 981 3241 1207 488 1476 894
v/s Ratio Prot 0.04 0.57 c0.23 c0.52
v/s Ratio Perm 0.07 0.60
v/c Ratio 0.07 0.57 0.67 0.20 0.60 0.86
Uniform Delay, d1 11.4 0.0 39.8 32.9 0.0 22.6
Progression Factor 1.31 1.00 0.85 0.39 1.00 1.00
Incremental Delay, d2 0.0 0.1 2.9 0.9 1.8 8.1
Delay (s) 14.9 0.1 36.6 13.6 1.8 30.7
Level of Service B A D B A C
Approach Delay (s) 0.6 30.7 1.8 30.7
Approach LOS A C A C
Intersection Summary
HCM 2000 Control Delay 12.9 HCM 2000 Level of Service B
HCM 2000 Volume to Capacity ratio 0.79
Actuated Cycle Length (s) 140.0 Sum of lost time (s) 8.0
Intersection Capacity Utilization 67.3% ICU Level of Service C
Analysis Period (min) 15
Description: SR 169/I-405 NB On-Ramp
c Critical Lane Group
+&06LJQDOL]HG,QWHUVHFWLRQ6XPPDU\
65 6KDUL
V'ULYHZD\10/29/2018
Cedar River Apartments 10/29/2018 2021 without Project PM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBU EBL EBT WBT WBR SBL SBR
Lane Configurations
Traffic Volume (veh/h) 16 43 2204 973 14 4 32
Future Volume (veh/h) 16 43 2204 973 14 4 32
Number 5 2 6 16 7 14
Initial Q (Qb), veh 0 0 0000
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1765 1765 1800 1765 1800
Adj Flow Rate, veh/h 48 2449 1081 16 4 36
Adj No. of Lanes 134000
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222200
Cap, veh/h 72 3315 4426 65 7 64
Arrive On Green 0.09 1.00 1.00 1.00 0.05 0.04
Sat Flow, veh/h 1681 4235 5906 80 148 1336
Grp Volume(v), veh/h 48 2449 745 352 41 0
Grp Sat Flow(s),veh/h/ln 1681 1235 1235 1751 1522 0
Q Serve(g_s), s 3.9 0.0 0.0 0.0 3.7 0.0
Cycle Q Clear(g_c), s 3.9 0.0 0.0 0.0 3.7 0.0
Prop In Lane 1.00 0.05 0.10 0.88
Lane Grp Cap(c), veh/h 72 3315 3051 1441 73 0
V/C Ratio(X) 0.67 0.74 0.24 0.24 0.56 0.00
Avail Cap(c_a), veh/h 144 3315 3051 1441 185 0
HCM Platoon Ratio 2.00 2.00 1.33 1.33 1.00 1.00
Upstream Filter(I) 0.79 0.79 0.97 0.97 1.00 0.00
Uniform Delay (d), s/veh 63.0 0.0 0.0 0.0 65.6 0.0
Incr Delay (d2), s/veh 8.1 1.2 0.2 0.4 6.5 0.0
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 1.9 0.4 0.1 0.2 1.7 0.0
LnGrp Delay(d),s/veh 71.1 1.2 0.2 0.4 72.1 0.0
LnGrp LOS EAAAE
Approach Vol, veh/h 2497 1097 41
Approach Delay, s/veh 2.5 0.3 72.1
Approach LOS A A E
Timer 12345678
Assigned Phs 2 4 5 6
Phs Duration (G+Y+Rc), s 129.2 10.8 10.0 119.2
Change Period (Y+Rc), s 5.0 5.0 5.0 5.0
Max Green Setting (Gmax), s 114.0 16.0 11.0 98.0
Max Q Clear Time (g_c+I1), s 2.0 5.7 5.9 2.0
Green Ext Time (p_c), s 63.1 0.1 0.0 58.1
Intersection Summary
HCM 2010 Ctrl Delay 2.6
HCM 2010 LOS A
Notes
+&06LJQDOL]HG,QWHUVHFWLRQ6XPPDU\
&HGDU5LYHU3DUN'U 6510/29/2018
Cedar River Apartments 10/29/2018 2021 without Project PM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBT EBR WBL WBT NBL NBR
Lane Configurations
Traffic Volume (veh/h) 2167 37 12 947 40 69
Future Volume (veh/h) 2167 37 12 947 40 69
Number 21216318
Initial Q (Qb), veh 0 0 0 0 0 0
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1800 1765 1765 1765 1765
Adj Flow Rate, veh/h 2408 41 13 1052 44 77
Adj No. of Lanes 301311
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222222
Cap, veh/h 3197 54 27 3664 216 193
Arrive On Green 1.00 1.00 0.02 0.81 0.13 0.13
Sat Flow, veh/h 4682 71 1681 4765 1681 1500
Grp Volume(v), veh/h 1431 1018 13 1052 44 77
Grp Sat Flow(s),veh/h/ln 1235 1752 1681 1500 1681 1500
Q Serve(g_s), s 0.0 0.0 1.1 7.9 3.3 6.6
Cycle Q Clear(g_c), s 0.0 0.0 1.1 7.9 3.3 6.6
Prop In Lane 0.04 1.00 1.00 1.00
Lane Grp Cap(c), veh/h 1902 1349 27 3664 216 193
V/C Ratio(X) 0.75 0.75 0.49 0.29 0.20 0.40
Avail Cap(c_a), veh/h 1902 1349 48 3664 216 193
HCM Platoon Ratio 2.00 2.00 1.00 1.00 1.00 1.00
Upstream Filter(I) 0.56 0.56 1.00 1.00 1.00 1.00
Uniform Delay (d), s/veh 0.0 0.0 68.3 3.2 54.6 56.0
Incr Delay (d2), s/veh 1.6 2.2 13.1 0.2 2.1 6.1
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 0.4 0.8 0.6 3.3 1.7 3.1
LnGrp Delay(d),s/veh 1.6 2.2 81.5 3.3 56.7 62.1
LnGrp LOS A A F A E E
Approach Vol, veh/h 2449 1065 121
Approach Delay, s/veh 1.9 4.3 60.1
Approach LOS A A E
Timer 12345678
Assigned Phs 1 2 6 8
Phs Duration (G+Y+Rc), s 6.2 111.8 118.0 22.0
Change Period (Y+Rc), s 5.0 5.0 5.0 5.0
Max Green Setting (Gmax), s 3.0 105.0 113.0 17.0
Max Q Clear Time (g_c+I1), s 3.1 2.0 9.9 8.6
Green Ext Time (p_c), s 0.0 54.1 54.1 0.2
Intersection Summary
HCM 2010 Ctrl Delay 4.5
HCM 2010 LOS A
+&06LJQDOL]HG,QWHUVHFWLRQ6XPPDU\
,6%2Q5DPS6XQVHW%OYG %URQVRQ:D\6510/29/2018
Cedar River Apartments 10/26/2018 2021 with Phase 1 Project PM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Traffic Volume (veh/h) 700 547 68 358 250 8110001222 775 664
Future Volume (veh/h) 700 547 68 358 250 811 0 0 0 1222 775 664
Number 5 2 12 1 6 16 7 4 14
Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1765 1800 1765 1765 1765 1765 1765 1765
Adj Flow Rate, veh/h 778 608 0 398 278 901 1358 861 738
Adj No. of Lanes 220121 211
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222222 222
Cap, veh/h 606 623 0 300 599 1093 1849 971 1104
Arrive On Green 0.19 0.19 0.00 0.18 0.18 0.18 0.55 0.55 0.55
Sat Flow, veh/h 3261 3441 0 1681 3353 1500 3361 1765 1500
Grp Volume(v), veh/h 778 608 0 398 278 901 1358 861 738
Grp Sat Flow(s),veh/h/ln 1630 1676 0 1681 1676 1500 1681 1765 1500
Q Serve(g_s), s 26.0 25.3 0.0 25.0 10.4 25.0 42.7 60.0 35.8
Cycle Q Clear(g_c), s 26.0 25.3 0.0 25.0 10.4 25.0 42.7 60.0 35.8
Prop In Lane 1.00 0.00 1.00 1.00 1.00 1.00
Lane Grp Cap(c), veh/h 606 623 0 300 599 1093 1849 971 1104
V/C Ratio(X) 1.28 0.98 0.00 1.33 0.46 0.82 0.73 0.89 0.67
Avail Cap(c_a), veh/h 606 623 0 300 599 1093 1849 971 1104
HCM Platoon Ratio 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
Upstream Filter(I) 1.00 1.00 0.00 0.55 0.55 0.55 0.40 0.40 0.40
Uniform Delay (d), s/veh 57.0 56.7 0.0 57.5 51.5 8.6 23.8 27.7 9.6
Incr Delay (d2), s/veh 140.4 30.1 0.0 159.0 0.3 2.9 1.1 5.2 1.3
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 23.5 14.3 0.0 24.8 4.9 35.7 20.1 30.6 25.6
LnGrp Delay(d),s/veh 197.4 86.8 0.0 216.5 51.8 11.5 24.8 32.9 10.9
LnGrp LOS F F F D B C C B
Approach Vol, veh/h 1386 1577 2957
Approach Delay, s/veh 148.9 70.4 23.7
Approach LOS F E C
Timer 12345678
Assigned Phs 2 4 6
Phs Duration (G+Y+Rc), s 30.0 81.0 29.0
Change Period (Y+Rc), s 5.0 5.0 5.0
Max Green Setting (Gmax), s 25.0 76.0 24.0
Max Q Clear Time (g_c+I1), s 28.0 62.0 27.0
Green Ext Time (p_c), s 0.0 11.8 0.0
Intersection Summary
HCM 2010 Ctrl Delay 65.4
HCM 2010 LOS E
Notes
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,1%2II5DPS,1%2Q5DPS 6510/29/2018
Cedar River Apartments 10/29/2018 2021 Phase 1 PM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Traffic Volume (vph) 63 1706 0 0 757 266 0 0 818 0 0 699
Future Volume (vph) 63 1706 0 0 757 266 0 0 818 0 0 699
Ideal Flow (vphpl) 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800
Total Lost time (s) 4.0 4.0 4.0 4.0 4.0 4.0
Lane Util. Factor 1.00 0.95 *0.70 1.00 1.00 1.00
Frt 1.00 1.00 1.00 0.85 0.86 0.86
Flt Protected 0.95 1.00 1.00 1.00 1.00 1.00
Satd. Flow (prot) 1621 3241 3582 1450 1476 1476
Flt Permitted 0.95 1.00 1.00 1.00 1.00 1.00
Satd. Flow (perm) 1621 3241 3582 1450 1476 1476
Peak-hour factor, PHF 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90
Adj. Flow (vph) 70 1896 0 0 841 296 0 0 909 0 0 777
RTOR Reduction (vph)000001960000011
Lane Group Flow (vph) 70 1896 0 0 841 100 0 0 909 0 0 766
Turn Type Prot NA NA Perm Free Over
Protected Phases 5 2 6 5
Permitted Phases 6 Free
Actuated Green, G (s) 83.9 140.0 46.1 46.1 140.0 83.9
Effective Green, g (s) 84.9 140.0 47.1 47.1 140.0 84.9
Actuated g/C Ratio 0.61 1.00 0.34 0.34 1.00 0.61
Clearance Time (s) 5.0 5.0 5.0 5.0 5.0
Vehicle Extension (s) 3.0 3.0 3.0 3.0 3.0
Lane Grp Cap (vph) 983 3241 1205 487 1476 895
v/s Ratio Prot 0.04 0.58 c0.23 c0.52
v/s Ratio Perm 0.07 0.62
v/c Ratio 0.07 0.59 0.70 0.20 0.62 0.86
Uniform Delay, d1 11.3 0.0 40.3 33.1 0.0 22.6
Progression Factor 1.31 1.00 0.81 0.28 1.00 1.00
Incremental Delay, d2 0.0 0.1 3.3 0.9 1.9 8.1
Delay (s) 14.9 0.1 35.9 10.1 1.9 30.6
Level of Service B A D B A C
Approach Delay (s) 0.6 29.2 1.9 30.6
Approach LOS A C A C
Intersection Summary
HCM 2000 Control Delay 12.5 HCM 2000 Level of Service B
HCM 2000 Volume to Capacity ratio 0.80
Actuated Cycle Length (s) 140.0 Sum of lost time (s) 8.0
Intersection Capacity Utilization 67.8% ICU Level of Service C
Analysis Period (min) 15
Description: SR 169/I-405 NB On-Ramp
c Critical Lane Group
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65 6KDUL
V'ULYHZD\10/29/2018
Cedar River Apartments 10/26/2018 2021 with Phase 1 Project PM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBU EBL EBT WBT WBR SBL SBR
Lane Configurations
Traffic Volume (veh/h) 16 43 2258 1007 14 4 32
Future Volume (veh/h) 16 43 2258 1007 14 4 32
Number 5 2 6 16 7 14
Initial Q (Qb), veh 0 0 0000
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1765 1765 1800 1765 1800
Adj Flow Rate, veh/h 48 2509 1119 16 4 36
Adj No. of Lanes 134000
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222200
Cap, veh/h 73 3315 4427 63 7 64
Arrive On Green 0.04 0.89 1.00 1.00 0.05 0.04
Sat Flow, veh/h 1681 4235 5910 77 148 1336
Grp Volume(v), veh/h 48 2509 770 365 41 0
Grp Sat Flow(s),veh/h/ln 1681 1235 1235 1751 1522 0
Q Serve(g_s), s 3.9 30.9 0.0 0.0 3.7 0.0
Cycle Q Clear(g_c), s 3.9 30.9 0.0 0.0 3.7 0.0
Prop In Lane 1.00 0.04 0.10 0.88
Lane Grp Cap(c), veh/h 73 3315 3049 1441 73 0
V/C Ratio(X) 0.66 0.76 0.25 0.25 0.56 0.00
Avail Cap(c_a), veh/h 144 3315 3049 1441 185 0
HCM Platoon Ratio 1.00 1.00 1.33 1.33 1.00 1.00
Upstream Filter(I) 0.33 0.33 0.96 0.96 1.00 0.00
Uniform Delay (d), s/veh 66.0 2.4 0.0 0.0 65.6 0.0
Incr Delay (d2), s/veh 3.4 0.6 0.2 0.4 6.5 0.0
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 1.9 10.2 0.1 0.2 1.7 0.0
LnGrp Delay(d),s/veh 69.3 3.0 0.2 0.4 72.1 0.0
LnGrp LOS EAAAE
Approach Vol, veh/h 2557 1135 41
Approach Delay, s/veh 4.2 0.3 72.1
Approach LOS A A E
Timer 12345678
Assigned Phs 2 4 5 6
Phs Duration (G+Y+Rc), s 129.2 10.8 10.0 119.2
Change Period (Y+Rc), s 5.0 5.0 5.0 5.0
Max Green Setting (Gmax), s 114.0 16.0 11.0 98.0
Max Q Clear Time (g_c+I1), s 32.9 5.7 5.9 2.0
Green Ext Time (p_c), s 55.0 0.1 0.0 61.1
Intersection Summary
HCM 2010 Ctrl Delay 3.8
HCM 2010 LOS A
Notes
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&HGDU5LYHU3DUN'U 6510/29/2018
Cedar River Apartments 10/26/2018 2021 with Phase 1 Project PM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBT EBR WBL WBT NBL NBR
Lane Configurations
Traffic Volume (veh/h) 2167 91 17 947 75 69
Future Volume (veh/h) 2167 91 17 947 75 69
Number 21216318
Initial Q (Qb), veh 0 0 0 0 0 0
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1800 1765 1765 1765 1765
Adj Flow Rate, veh/h 2408 101 19 1052 83 77
Adj No. of Lanes 301311
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222222
Cap, veh/h 3118 130 34 3696 204 182
Arrive On Green 1.00 1.00 0.02 0.82 0.12 0.12
Sat Flow, veh/h 4567 168 1681 4765 1681 1500
Grp Volume(v), veh/h 1469 1040 19 1052 83 77
Grp Sat Flow(s),veh/h/ln 1235 1735 1681 1500 1681 1500
Q Serve(g_s), s 0.0 0.0 1.6 7.6 6.4 6.7
Cycle Q Clear(g_c), s 0.0 0.0 1.6 7.6 6.4 6.7
Prop In Lane 0.10 1.00 1.00 1.00
Lane Grp Cap(c), veh/h 1908 1340 34 3696 204 182
V/C Ratio(X) 0.77 0.78 0.55 0.28 0.41 0.42
Avail Cap(c_a), veh/h 1908 1340 48 3696 204 182
HCM Platoon Ratio 2.00 2.00 1.00 1.00 1.00 1.00
Upstream Filter(I) 0.53 0.53 1.00 1.00 1.00 1.00
Uniform Delay (d), s/veh 0.0 0.0 67.9 2.9 56.8 57.0
Incr Delay (d2), s/veh 1.6 2.4 13.1 0.2 5.9 7.0
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 0.4 0.9 0.9 3.2 3.3 3.1
LnGrp Delay(d),s/veh 1.6 2.4 81.1 3.1 62.8 64.0
LnGrp LOS A A F A E E
Approach Vol, veh/h 2509 1071 160
Approach Delay, s/veh 2.0 4.5 63.4
Approach LOS A A E
Timer 12345678
Assigned Phs 1 2 6 8
Phs Duration (G+Y+Rc), s 6.9 112.1 119.0 21.0
Change Period (Y+Rc), s 5.0 5.0 5.0 5.0
Max Green Setting (Gmax), s 3.0 106.0 114.0 16.0
Max Q Clear Time (g_c+I1), s 3.6 2.0 9.6 8.7
Green Ext Time (p_c), s 0.0 57.0 57.1 0.3
Intersection Summary
HCM 2010 Ctrl Delay 5.3
HCM 2010 LOS A
+&07:6&
6LWH(DVW$FFHVV 6510/29/2018
Cedar River Apartments 10/29/2018 2021 Phase 1 PM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Intersection
Int Delay, s/veh 0.1
Movement EBT EBR WBL WBT NBL NBR
Lane Configurations
Traffic Vol, veh/h 2235 1 5 964 0 6
Future Vol, veh/h 2235 1 5 964 0 6
Conflicting Peds, #/hr 000000
Sign Control Free Free Free Free Stop Stop
RT Channelized - None - None - None
Storage Length - 0 150 - 150 0
Veh in Median Storage, # 0 - - 0 0 -
Grade, % 0 - - 0 0 -
Peak Hour Factor 90 90 90 90 90 90
Heavy Vehicles, %222222
Mvmt Flow 2483 1 6 1071 0 7
Major/Minor Major1 Major2 Minor1
Conflicting Flow All 0 0 2483 0 2923 1242
Stage 1 - - - - 2483 -
Stage 2 - - - - 440 -
Critical Hdwy - - 4.14 - 6.29 6.94
Critical Hdwy Stg 1 - - - - 5.84 -
Critical Hdwy Stg 2 - - - - 6.04 -
Follow-up Hdwy - - 2.22 - 3.67 3.32
Pot Cap-1 Maneuver - - 182 - 19 166
Stage 1 - - - - 48 -
Stage 2 - - - - 582 -
Platoon blocked, % - - -
Mov Cap-1 Maneuver - - 182 - 18 166
Mov Cap-2 Maneuver - - - - 18 -
Stage 1 - - - - 48 -
Stage 2 - - - - 563 -
Approach EB WB NB
HCM Control Delay, s 0 0.1 27.6
HCM LOS D
Minor Lane/Major Mvmt NBLn1NBLn2 EBT EBR WBL WBT
Capacity (veh/h) - 166 - - 182 -
HCM Lane V/C Ratio - 0.04 - - 0.031 -
HCM Control Delay (s) 0 27.6 - - 25.4 -
HCM Lane LOS A D - - D -
HCM 95th %tile Q(veh) - 0.1 - - 0.1 -
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,6%2Q5DPS6XQVHW%OYG %URQVRQ:D\6510/29/2018
Cedar River Apartments 10/29/2018 2022 with Phase 2 Project PM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Traffic Volume (veh/h) 707 560 68 372 256 8290001269 783 671
Future Volume (veh/h) 707 560 68 372 256 829 0 0 0 1269 783 671
Number 5 2 12 1 6 16 7 4 14
Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1765 1800 1765 1765 1765 1765 1765 1765
Adj Flow Rate, veh/h 786 622 0 413 284 921 1410 870 746
Adj No. of Lanes 220121 211
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222222 222
Cap, veh/h 582 599 0 312 623 1104 1849 971 1093
Arrive On Green 0.18 0.18 0.00 0.06 0.06 0.06 0.55 0.55 0.55
Sat Flow, veh/h 3261 3441 0 1681 3353 1500 3361 1765 1500
Grp Volume(v), veh/h 786 622 0 413 284 921 1410 870 746
Grp Sat Flow(s),veh/h/ln 1630 1676 0 1681 1676 1500 1681 1765 1500
Q Serve(g_s), s 25.0 25.0 0.0 26.0 11.5 26.0 45.5 61.3 37.6
Cycle Q Clear(g_c), s 25.0 25.0 0.0 26.0 11.5 26.0 45.5 61.3 37.6
Prop In Lane 1.00 0.00 1.00 1.00 1.00 1.00
Lane Grp Cap(c), veh/h 582 599 0 312 623 1104 1849 971 1093
V/C Ratio(X) 1.35 1.04 0.00 1.32 0.46 0.83 0.76 0.90 0.68
Avail Cap(c_a), veh/h 582 599 0 312 623 1104 1849 971 1093
HCM Platoon Ratio 1.00 1.00 1.00 0.33 0.33 0.33 1.00 1.00 1.00
Upstream Filter(I) 1.00 1.00 0.00 0.51 0.51 0.51 0.40 0.40 0.40
Uniform Delay (d), s/veh 57.5 57.5 0.0 65.7 58.9 9.6 24.4 28.0 10.3
Incr Delay (d2), s/veh 168.6 47.2 0.0 156.7 0.3 3.0 1.2 5.7 1.4
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 24.9 15.5 0.0 25.7 5.4 36.7 21.3 31.3 26.1
LnGrp Delay(d),s/veh 226.1 104.7 0.0 222.4 59.1 12.6 25.6 33.6 11.7
LnGrp LOS F F F E B C C B
Approach Vol, veh/h 1408 1618 3026
Approach Delay, s/veh 172.5 74.3 24.5
Approach LOS F E C
Timer 12345678
Assigned Phs 2 4 6
Phs Duration (G+Y+Rc), s 29.0 81.0 30.0
Change Period (Y+Rc), s 5.0 5.0 5.0
Max Green Setting (Gmax), s 24.0 76.0 25.0
Max Q Clear Time (g_c+I1), s 27.0 63.3 28.0
Green Ext Time (p_c), s 0.0 11.0 0.0
Intersection Summary
HCM 2010 Ctrl Delay 72.2
HCM 2010 LOS E
Notes
+&06LJQDOL]HG,QWHUVHFWLRQ&DSDFLW\$QDO\VLV
,1%2II5DPS,1%2Q5DPS 6510/29/2018
Cedar River Apartments 10/29/2018 2022 with Phase 2 Project PM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Traffic Volume (vph) 64 1764 0 0 789 280 0 0 843 0 0 706
Future Volume (vph) 64 1764 0 0 789 280 0 0 843 0 0 706
Ideal Flow (vphpl) 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800
Total Lost time (s) 4.0 4.0 4.0 4.0 4.0 4.0
Lane Util. Factor 1.00 0.95 *0.70 1.00 1.00 1.00
Frt 1.00 1.00 1.00 0.85 0.86 0.86
Flt Protected 0.95 1.00 1.00 1.00 1.00 1.00
Satd. Flow (prot) 1621 3241 3582 1450 1476 1476
Flt Permitted 0.95 1.00 1.00 1.00 1.00 1.00
Satd. Flow (perm) 1621 3241 3582 1450 1476 1476
Peak-hour factor, PHF 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90
Adj. Flow (vph) 71 1960 0 0 877 311 0 0 937 0 0 784
RTOR Reduction (vph)000002030000010
Lane Group Flow (vph) 71 1960 0 0 877 108 0 0 937 0 0 774
Turn Type Prot NA NA Perm Free Over
Protected Phases 5 2 6 5
Permitted Phases 6 Free
Actuated Green, G (s) 83.4 140.0 46.6 46.6 140.0 83.4
Effective Green, g (s) 84.4 140.0 47.6 47.6 140.0 84.4
Actuated g/C Ratio 0.60 1.00 0.34 0.34 1.00 0.60
Clearance Time (s) 5.0 5.0 5.0 5.0 5.0
Vehicle Extension (s) 3.0 3.0 3.0 3.0 3.0
Lane Grp Cap (vph) 977 3241 1217 493 1476 889
v/s Ratio Prot 0.04 0.60 c0.24 c0.52
v/s Ratio Perm 0.07 0.64
v/c Ratio 0.07 0.60 0.72 0.22 0.63 0.87
Uniform Delay, d1 11.5 0.0 40.4 33.0 0.0 23.2
Progression Factor 1.31 1.00 0.78 0.20 1.00 1.00
Incremental Delay, d2 0.0 0.1 3.6 1.0 2.1 9.3
Delay (s) 15.2 0.1 35.0 7.6 2.1 32.5
Level of Service B A D A A C
Approach Delay (s) 0.6 27.8 2.1 32.5
Approach LOS A C A C
Intersection Summary
HCM 2000 Control Delay 12.5 HCM 2000 Level of Service B
HCM 2000 Volume to Capacity ratio 0.82
Actuated Cycle Length (s) 140.0 Sum of lost time (s) 8.0
Intersection Capacity Utilization 68.9% ICU Level of Service C
Analysis Period (min) 15
Description: SR 169/I-405 NB On-Ramp
c Critical Lane Group
+&06LJQDOL]HG,QWHUVHFWLRQ6XPPDU\
65 6KDUL
V'ULYHZD\10/29/2018
Cedar River Apartments 10/29/2018 2022 with Phase 2 Project PM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBU EBL EBT WBT WBR SBL SBR
Lane Configurations
Traffic Volume (veh/h) 16 43 2339 1053 14 4 33
Future Volume (veh/h) 16 43 2339 1053 14 4 33
Number 5 2 6 16 7 14
Initial Q (Qb), veh 0 0 0000
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1765 1765 1800 1765 1800
Adj Flow Rate, veh/h 48 2599 1170 16 4 37
Adj No. of Lanes 134000
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222200
Cap, veh/h 72 3313 4428 61 7 66
Arrive On Green 0.09 1.00 1.00 1.00 0.05 0.04
Sat Flow, veh/h 1681 4235 5913 74 145 1340
Grp Volume(v), veh/h 48 2599 805 381 42 0
Grp Sat Flow(s),veh/h/ln 1681 1235 1235 1752 1521 0
Q Serve(g_s), s 3.9 0.0 0.0 0.0 3.8 0.0
Cycle Q Clear(g_c), s 3.9 0.0 0.0 0.0 3.8 0.0
Prop In Lane 1.00 0.04 0.10 0.88
Lane Grp Cap(c), veh/h 72 3313 3048 1441 74 0
V/C Ratio(X) 0.67 0.78 0.26 0.26 0.56 0.00
Avail Cap(c_a), veh/h 144 3313 3048 1441 185 0
HCM Platoon Ratio 2.00 2.00 1.33 1.33 1.00 1.00
Upstream Filter(I) 0.75 0.75 0.95 0.95 1.00 0.00
Uniform Delay (d), s/veh 63.0 0.0 0.0 0.0 65.6 0.0
Incr Delay (d2), s/veh 7.7 1.5 0.2 0.4 6.5 0.0
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 1.9 0.5 0.1 0.2 1.7 0.0
LnGrp Delay(d),s/veh 70.8 1.5 0.2 0.4 72.1 0.0
LnGrp LOS EAAAE
Approach Vol, veh/h 2647 1186 42
Approach Delay, s/veh 2.7 0.3 72.1
Approach LOS A A E
Timer 12345678
Assigned Phs 2 4 5 6
Phs Duration (G+Y+Rc), s 129.1 10.9 10.0 119.2
Change Period (Y+Rc), s 5.0 5.0 5.0 5.0
Max Green Setting (Gmax), s 114.0 16.0 11.0 98.0
Max Q Clear Time (g_c+I1), s 2.0 5.8 5.9 2.0
Green Ext Time (p_c), s 72.1 0.1 0.0 65.4
Intersection Summary
HCM 2010 Ctrl Delay 2.7
HCM 2010 LOS A
Notes
+&06LJQDOL]HG,QWHUVHFWLRQ6XPPDU\
&HGDU5LYHU3DUN'U 6510/29/2018
Cedar River Apartments 10/29/2018 2022 with Phase 2 Project PM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBT EBR WBL WBT NBL NBR
Lane Configurations
Traffic Volume (veh/h) 2196 142 23 956 112 69
Future Volume (veh/h) 2196 142 23 956 112 69
Number 21216318
Initial Q (Qb), veh 0 0 0 0 0 0
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1800 1765 1765 1765 1765
Adj Flow Rate, veh/h 2440 158 26 1062 124 77
Adj No. of Lanes 301311
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222222
Cap, veh/h 3020 194 44 3696 204 182
Arrive On Green 1.00 1.00 0.03 0.82 0.12 0.12
Sat Flow, veh/h 4468 253 1681 4765 1681 1500
Grp Volume(v), veh/h 1522 1076 26 1062 124 77
Grp Sat Flow(s),veh/h/ln 1235 1720 1681 1500 1681 1500
Q Serve(g_s), s 0.0 0.0 2.1 7.7 9.8 6.7
Cycle Q Clear(g_c), s 0.0 0.0 2.1 7.7 9.8 6.7
Prop In Lane 0.15 1.00 1.00 1.00
Lane Grp Cap(c), veh/h 1895 1319 44 3696 204 182
V/C Ratio(X) 0.80 0.82 0.60 0.29 0.61 0.42
Avail Cap(c_a), veh/h 1895 1319 48 3696 204 182
HCM Platoon Ratio 2.00 2.00 1.00 1.00 1.00 1.00
Upstream Filter(I) 0.48 0.48 1.00 1.00 1.00 1.00
Uniform Delay (d), s/veh 0.0 0.0 67.5 2.9 58.3 57.0
Incr Delay (d2), s/veh 1.8 2.8 15.7 0.2 12.7 7.0
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 0.5 1.0 1.2 3.2 5.3 3.1
LnGrp Delay(d),s/veh 1.8 2.8 83.2 3.1 71.1 64.0
LnGrp LOS A A F A E E
Approach Vol, veh/h 2598 1088 201
Approach Delay, s/veh 2.2 5.0 68.4
Approach LOS A A E
Timer 12345678
Assigned Phs 1 2 6 8
Phs Duration (G+Y+Rc), s 7.6 111.4 119.0 21.0
Change Period (Y+Rc), s 5.0 5.0 5.0 5.0
Max Green Setting (Gmax), s 3.0 106.0 114.0 16.0
Max Q Clear Time (g_c+I1), s 4.1 2.0 9.7 11.8
Green Ext Time (p_c), s 0.0 61.0 61.1 0.3
Intersection Summary
HCM 2010 Ctrl Delay 6.4
HCM 2010 LOS A
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Cedar River Apartments 10/29/2018 2022 with Phase 2 Project PM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Intersection
Int Delay, s/veh 0.2
Movement EBT EBR WBL WBT NBL NBR
Lane Configurations
Traffic Vol, veh/h 2258 8 10 979 0 13
Future Vol, veh/h 2258 8 10 979 0 13
Conflicting Peds, #/hr 000000
Sign Control Free Free Free Free Stop Stop
RT Channelized - None - None - None
Storage Length - 0 150 - 150 0
Veh in Median Storage, # 0 - - 0 0 -
Grade, % 0 - - 0 0 -
Peak Hour Factor 90 90 90 90 90 90
Heavy Vehicles, %222222
Mvmt Flow 2509 9 11 1088 0 14
Major/Minor Major1 Major2 Minor1
Conflicting Flow All 0 0 2509 0 2966 1254
Stage 1 - - - - 2509 -
Stage 2 - - - - 457 -
Critical Hdwy - - 4.14 - 6.29 6.94
Critical Hdwy Stg 1 - - - - 5.84 -
Critical Hdwy Stg 2 - - - - 6.04 -
Follow-up Hdwy - - 2.22 - 3.67 3.32
Pot Cap-1 Maneuver - - 178 - 18 163
Stage 1 - - - - 46 -
Stage 2 - - - - 570 -
Platoon blocked, % - - -
Mov Cap-1 Maneuver - - 178 - 17 163
Mov Cap-2 Maneuver - - - - 17 -
Stage 1 - - - - 46 -
Stage 2 - - - - 535 -
Approach EB WB NB
HCM Control Delay, s 0 0.3 29.2
HCM LOS D
Minor Lane/Major Mvmt NBLn1NBLn2 EBT EBR WBL WBT
Capacity (veh/h) - 163 - - 178 -
HCM Lane V/C Ratio - 0.089 - - 0.062 -
HCM Control Delay (s) 0 29.2 - - 26.6 -
HCM Lane LOS A D - - D -
HCM 95th %tile Q(veh) - 0.3 - - 0.2 -
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BPJ; William Popp Associates
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Traffic Volume (veh/h) 714 567 69 387 265 8530001290 791 677
Future Volume (veh/h) 714 567 69 387 265 853 0 0 0 1290 791 677
Number 5 2 12 1 6 16 7 4 14
Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1765 1800 1765 1765 1765 1765 1765 1765
Adj Flow Rate, veh/h 793 630 0 430 294 948 1433 879 752
Adj No. of Lanes 220121 211
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222222 222
Cap, veh/h 582 599 0 312 623 1104 1849 971 1093
Arrive On Green 0.18 0.18 0.00 0.06 0.06 0.06 0.55 0.55 0.55
Sat Flow, veh/h 3261 3441 0 1681 3353 1500 3361 1765 1500
Grp Volume(v), veh/h 793 630 0 430 294 948 1433 879 752
Grp Sat Flow(s),veh/h/ln 1630 1676 0 1681 1676 1500 1681 1765 1500
Q Serve(g_s), s 25.0 25.0 0.0 26.0 11.9 26.0 46.8 62.5 38.2
Cycle Q Clear(g_c), s 25.0 25.0 0.0 26.0 11.9 26.0 46.8 62.5 38.2
Prop In Lane 1.00 0.00 1.00 1.00 1.00 1.00
Lane Grp Cap(c), veh/h 582 599 0 312 623 1104 1849 971 1093
V/C Ratio(X) 1.36 1.05 0.00 1.38 0.47 0.86 0.78 0.91 0.69
Avail Cap(c_a), veh/h 582 599 0 312 623 1104 1849 971 1093
HCM Platoon Ratio 1.00 1.00 1.00 0.33 0.33 0.33 1.00 1.00 1.00
Upstream Filter(I) 1.00 1.00 0.00 0.48 0.48 0.48 0.40 0.40 0.40
Uniform Delay (d), s/veh 57.5 57.5 0.0 65.7 59.1 9.6 24.7 28.2 10.3
Incr Delay (d2), s/veh 173.8 51.3 0.0 179.5 0.3 3.5 1.3 6.2 1.4
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 25.3 15.8 0.0 27.7 5.5 37.9 22.0 31.9 26.5
LnGrp Delay(d),s/veh 231.3 108.8 0.0 245.2 59.3 13.1 26.0 34.4 11.8
LnGrp LOS F F F E B C C B
Approach Vol, veh/h 1423 1672 3064
Approach Delay, s/veh 177.1 80.9 24.9
Approach LOS F F C
Timer 12345678
Assigned Phs 2 4 6
Phs Duration (G+Y+Rc), s 29.0 81.0 30.0
Change Period (Y+Rc), s 5.0 5.0 5.0
Max Green Setting (Gmax), s 24.0 76.0 25.0
Max Q Clear Time (g_c+I1), s 27.0 64.5 28.0
Green Ext Time (p_c), s 0.0 10.1 0.0
Intersection Summary
HCM 2010 Ctrl Delay 75.3
HCM 2010 LOS E
Notes
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Cedar River Apartments 10/29/2018 2023 with Phase 3 Project PM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Traffic Volume (vph) 65 1793 0 0 829 293 0 0 856 0 0 713
Future Volume (vph) 65 1793 0 0 829 293 0 0 856 0 0 713
Ideal Flow (vphpl) 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800 1800
Total Lost time (s) 4.0 4.0 4.0 4.0 4.0 4.0
Lane Util. Factor 1.00 0.95 *0.70 1.00 1.00 1.00
Frt 1.00 1.00 1.00 0.85 0.86 0.86
Flt Protected 0.95 1.00 1.00 1.00 1.00 1.00
Satd. Flow (prot) 1621 3241 3582 1450 1476 1476
Flt Permitted 0.95 1.00 1.00 1.00 1.00 1.00
Satd. Flow (perm) 1621 3241 3582 1450 1476 1476
Peak-hour factor, PHF 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90
Adj. Flow (vph) 72 1992 0 0 921 326 0 0 951 0 0 792
RTOR Reduction (vph)00000204000009
Lane Group Flow (vph) 72 1992 0 0 921 122 0 0 951 0 0 783
Turn Type Prot NA NA Perm Free Over
Protected Phases 5 2 6 5
Permitted Phases 6 Free
Actuated Green, G (s) 83.0 140.0 47.0 47.0 140.0 83.0
Effective Green, g (s) 84.0 140.0 48.0 48.0 140.0 84.0
Actuated g/C Ratio 0.60 1.00 0.34 0.34 1.00 0.60
Clearance Time (s) 5.0 5.0 5.0 5.0 5.0
Vehicle Extension (s) 3.0 3.0 3.0 3.0 3.0
Lane Grp Cap (vph) 972 3241 1228 497 1476 885
v/s Ratio Prot 0.04 0.61 c0.26 c0.53
v/s Ratio Perm 0.08 0.64
v/c Ratio 0.07 0.61 0.75 0.25 0.64 0.88
Uniform Delay, d1 11.7 0.0 40.7 33.0 0.0 23.9
Progression Factor 1.31 1.00 0.74 0.16 1.00 1.00
Incremental Delay, d2 0.0 0.1 4.1 1.1 2.2 10.5
Delay (s) 15.3 0.1 34.3 6.4 2.2 34.4
Level of Service B A C A A C
Approach Delay (s) 0.6 27.0 2.2 34.4
Approach LOS A C A C
Intersection Summary
HCM 2000 Control Delay 12.7 HCM 2000 Level of Service B
HCM 2000 Volume to Capacity ratio 0.84
Actuated Cycle Length (s) 140.0 Sum of lost time (s) 8.0
Intersection Capacity Utilization 70.2% ICU Level of Service C
Analysis Period (min) 15
Description: SR 169/I-405 NB On-Ramp
c Critical Lane Group
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Cedar River Apartments 10/29/2018 2023 with Phase 3 Project PM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBU EBL EBT WBT WBR SBL SBR
Lane Configurations
Traffic Volume (veh/h) 16 44 2377 1107 14 4 33
Future Volume (veh/h) 16 44 2377 1107 14 4 33
Number 5 2 6 16 7 14
Initial Q (Qb), veh 0 0 0000
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1765 1765 1800 1765 1800
Adj Flow Rate, veh/h 49 2641 1230 16 4 37
Adj No. of Lanes 134000
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222200
Cap, veh/h 73 3313 4428 58 7 66
Arrive On Green 0.09 1.00 1.00 1.00 0.05 0.04
Sat Flow, veh/h 1681 4235 5918 70 145 1340
Grp Volume(v), veh/h 49 2641 846 400 42 0
Grp Sat Flow(s),veh/h/ln 1681 1235 1235 1752 1521 0
Q Serve(g_s), s 4.0 0.0 0.0 0.0 3.8 0.0
Cycle Q Clear(g_c), s 4.0 0.0 0.0 0.0 3.8 0.0
Prop In Lane 1.00 0.04 0.10 0.88
Lane Grp Cap(c), veh/h 73 3313 3045 1440 74 0
V/C Ratio(X) 0.67 0.80 0.28 0.28 0.56 0.00
Avail Cap(c_a), veh/h 144 3313 3045 1440 185 0
HCM Platoon Ratio 2.00 2.00 1.33 1.33 1.00 1.00
Upstream Filter(I) 0.74 0.74 0.93 0.93 1.00 0.00
Uniform Delay (d), s/veh 62.9 0.0 0.0 0.0 65.6 0.0
Incr Delay (d2), s/veh 7.6 1.6 0.2 0.4 6.5 0.0
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 2.0 0.5 0.1 0.2 1.7 0.0
LnGrp Delay(d),s/veh 70.5 1.6 0.2 0.4 72.1 0.0
LnGrp LOS EAAAE
Approach Vol, veh/h 2690 1246 42
Approach Delay, s/veh 2.8 0.3 72.1
Approach LOS A A E
Timer 12345678
Assigned Phs 2 4 5 6
Phs Duration (G+Y+Rc), s 129.1 10.9 10.1 119.0
Change Period (Y+Rc), s 5.0 5.0 5.0 5.0
Max Green Setting (Gmax), s 114.0 16.0 11.0 98.0
Max Q Clear Time (g_c+I1), s 2.0 5.8 6.0 2.0
Green Ext Time (p_c), s 75.4 0.1 0.0 68.1
Intersection Summary
HCM 2010 Ctrl Delay 2.8
HCM 2010 LOS A
Notes
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Cedar River Apartments 10/29/2018 2023 with Phase 3 Project PM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBT EBR WBL WBT NBL NBR
Lane Configurations
Traffic Volume (veh/h) 2224 153 24 966 157 73
Future Volume (veh/h) 2224 153 24 966 157 73
Number 21216318
Initial Q (Qb), veh 0 0 0 0 0 0
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1800 1765 1765 1765 1765
Adj Flow Rate, veh/h 2471 170 27 1073 174 81
Adj No. of Lanes 301311
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222222
Cap, veh/h 2976 202 45 3664 216 193
Arrive On Green 1.00 1.00 0.03 0.81 0.13 0.13
Sat Flow, veh/h 4451 267 1681 4765 1681 1500
Grp Volume(v), veh/h 1547 1094 27 1073 174 81
Grp Sat Flow(s),veh/h/ln 1235 1718 1681 1500 1681 1500
Q Serve(g_s), s 0.0 0.0 2.2 8.1 14.1 7.0
Cycle Q Clear(g_c), s 0.0 0.0 2.2 8.1 14.1 7.0
Prop In Lane 0.16 1.00 1.00 1.00
Lane Grp Cap(c), veh/h 1875 1304 45 3664 216 193
V/C Ratio(X) 0.82 0.84 0.60 0.29 0.81 0.42
Avail Cap(c_a), veh/h 1875 1304 48 3664 216 193
HCM Platoon Ratio 2.00 2.00 1.00 1.00 1.00 1.00
Upstream Filter(I) 0.46 0.46 1.00 1.00 1.00 1.00
Uniform Delay (d), s/veh 0.0 0.0 67.4 3.2 59.3 56.2
Incr Delay (d2), s/veh 2.0 3.2 17.2 0.2 26.5 6.6
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 0.5 1.1 1.3 3.3 8.1 3.2
LnGrp Delay(d),s/veh 2.0 3.2 84.6 3.4 85.8 62.8
LnGrp LOS A A F A F E
Approach Vol, veh/h 2641 1100 255
Approach Delay, s/veh 2.5 5.4 78.5
Approach LOS A A E
Timer 12345678
Assigned Phs 1 2 6 8
Phs Duration (G+Y+Rc), s 7.7 110.3 118.0 22.0
Change Period (Y+Rc), s 5.0 5.0 5.0 5.0
Max Green Setting (Gmax), s 3.0 105.0 113.0 17.0
Max Q Clear Time (g_c+I1), s 4.2 2.0 10.1 16.1
Green Ext Time (p_c), s 0.0 62.8 62.7 0.1
Intersection Summary
HCM 2010 Ctrl Delay 8.1
HCM 2010 LOS A
+&07:6&
6LWH(DVW$FFHVV 6510/29/2018
Cedar River Apartments 10/29/2018 2023 with Phase 3 Project PM Peak Synchro 9 Light Report
BPJ; William Popp Associates
Intersection
Int Delay, s/veh 0.4
Movement EBT EBR WBL WBT NBL NBR
Lane Configurations
Traffic Vol, veh/h 2283 14 14 990 0 25
Future Vol, veh/h 2283 14 14 990 0 25
Conflicting Peds, #/hr 000000
Sign Control Free Free Free Free Stop Stop
RT Channelized - None - None - None
Storage Length - 0 150 - 150 0
Veh in Median Storage, # 0 - - 0 0 -
Grade, % 0 - - 0 0 -
Peak Hour Factor 90 90 90 90 90 90
Heavy Vehicles, %222222
Mvmt Flow 2537 16 16 1100 0 28
Major/Minor Major1 Major2 Minor1
Conflicting Flow All 0 0 2537 0 3008 1268
Stage 1 - - - - 2537 -
Stage 2 - - - - 471 -
Critical Hdwy - - 4.14 - 6.29 6.94
Critical Hdwy Stg 1 - - - - 5.84 -
Critical Hdwy Stg 2 - - - - 6.04 -
Follow-up Hdwy - - 2.22 - 3.67 3.32
Pot Cap-1 Maneuver - - 173 - 16 160
Stage 1 - - - - 45 -
Stage 2 - - - - 560 -
Platoon blocked, % - - -
Mov Cap-1 Maneuver - - 173 - 15 160
Mov Cap-2 Maneuver - - - - 15 -
Stage 1 - - - - 45 -
Stage 2 - - - - 508 -
Approach EB WB NB
HCM Control Delay, s 0 0.4 32.2
HCM LOS D
Minor Lane/Major Mvmt NBLn1NBLn2 EBT EBR WBL WBT
Capacity (veh/h) - 160 - - 173 -
HCM Lane V/C Ratio - 0.174 - - 0.09 -
HCM Control Delay (s) 0 32.2 - - 27.9 -
HCM Lane LOS A D - - D -
HCM 95th %tile Q(veh) - 0.6 - - 0.3 -
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Cedar River Apartments 10/30/2018 2023 with Phase 3 Project PM Peak -- dual WBL Synchro 9 Light Report
BPJ; William Popp Associates
Movement EBL EBT EBR WBL WBT WBR NBL NBT NBR SBL SBT SBR
Lane Configurations
Traffic Volume (veh/h) 714 567 69 387 265 8530001290 791 677
Future Volume (veh/h) 714 567 69 387 265 853 0 0 0 1290 791 677
Number 5 2 12 1 6 16 7 4 14
Initial Q (Qb), veh 0 0 0 0 0 0 0 0 0
Ped-Bike Adj(A_pbT) 1.00 1.00 1.00 1.00 1.00 1.00
Parking Bus, Adj 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
Adj Sat Flow, veh/h/ln 1765 1765 1800 1765 1765 1765 1765 1765 1765
Adj Flow Rate, veh/h 793 630 0 430 294 948 1433 879 752
Adj No. of Lanes 220211 211
Peak Hour Factor 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90 0.90
Percent Heavy Veh, % 222222 222
Cap, veh/h 582 599 0 624 328 1104 1849 971 1093
Arrive On Green 0.18 0.18 0.00 0.06 0.06 0.06 0.55 0.55 0.55
Sat Flow, veh/h 3261 3441 0 3361 1765 1500 3361 1765 1500
Grp Volume(v), veh/h 793 630 0 430 294 948 1433 879 752
Grp Sat Flow(s),veh/h/ln 1630 1676 0 1681 1765 1500 1681 1765 1500
Q Serve(g_s), s 25.0 25.0 0.0 17.6 23.2 26.0 46.8 62.5 38.2
Cycle Q Clear(g_c), s 25.0 25.0 0.0 17.6 23.2 26.0 46.8 62.5 38.2
Prop In Lane 1.00 0.00 1.00 1.00 1.00 1.00
Lane Grp Cap(c), veh/h 582 599 0 624 328 1104 1849 971 1093
V/C Ratio(X) 1.36 1.05 0.00 0.69 0.90 0.86 0.78 0.91 0.69
Avail Cap(c_a), veh/h 582 599 0 624 328 1104 1849 971 1093
HCM Platoon Ratio 1.00 1.00 1.00 0.33 0.33 0.33 1.00 1.00 1.00
Upstream Filter(I) 1.00 1.00 0.00 0.48 0.48 0.48 0.40 0.40 0.40
Uniform Delay (d), s/veh 57.5 57.5 0.0 61.7 64.4 9.6 24.7 28.2 10.3
Incr Delay (d2), s/veh 173.8 51.3 0.0 1.5 14.6 3.5 1.3 6.2 1.4
Initial Q Delay(d3),s/veh 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
%ile BackOfQ(50%),veh/ln 25.3 15.8 0.0 8.3 12.7 37.9 22.0 31.9 26.5
LnGrp Delay(d),s/veh 231.3 108.8 0.0 63.3 79.0 13.1 26.0 34.4 11.8
LnGrp LOS F F E E B C C B
Approach Vol, veh/h 1423 1672 3064
Approach Delay, s/veh 177.1 37.6 24.9
Approach LOS F D C
Timer 12345678
Assigned Phs 2 4 6
Phs Duration (G+Y+Rc), s 29.0 81.0 30.0
Change Period (Y+Rc), s 5.0 5.0 5.0
Max Green Setting (Gmax), s 24.0 76.0 25.0
Max Q Clear Time (g_c+I1), s 27.0 64.5 28.0
Green Ext Time (p_c), s 0.0 10.1 0.0
Intersection Summary
HCM 2010 Ctrl Delay 63.5
HCM 2010 LOS E
Notes
Exhibit 2
Opinion on Proposed Cleanup of the following Site, July 19, 2018,
Department of Ecology.
Mr. Jimmy Blais
July 19, 2018
Page 2
x Gasoline-, diesel-, and oil-range petroleum hydrocarbons (TPH-G, TPH-D, and TPH-O), and
formaldehyde into Soil.
x Formaldehyde, arsenic, and highly alkaline pH into Ground Water.
Enclosure A includes a detailed description and diagram of the Site, as currently known to
Ecology.
Please note a parcel of real property can be affected by multiple sites. At this time, we have no
information that the parcel(s) associated with this Site are affected by other sites.
Basis for the Opinion
This opinion is based on the information contained in the documents listed in Enclosure B.
Those documents are kept in the Central Files of the Northwest Regional Office of Ecology
(NWRO) for review by appointment only. You can make an appointment by completing a
Request for Public Record form (https://www.ecology.wa.gov/About-us/Accountability-
transparency/Public-records-requests) and emailing it to PublicRecordsOfficer@ecy.wa.gov, or
contacting the Public Records Officer at 360-407-6040. A number of these documents are
accessible in electronic form from the Site web page
(https://fortress.wa.gov/ecy/gsp/Sitepage.aspx?csid=2121).
This opinion is void if any of the information contained in those documents is materially false or
misleading.
Analysis of the Cleanup
Ecology has concluded that, upon completion of your proposed cleanup, no further remedial
action will likely be necessary to clean up contamination at the Site. That conclusion is based on
the following analysis:
1. Characterization of the Site.
Ecology has determined your characterization of the Site is sufficient to establish cleanup
standards and select a cleanup action. The Site is described above and in Enclosure A.
The lateral and vertical extent of soil and ground water impacted by contaminant releases
at the Site have been adequately defined by completion of Site investigations conducted
from September 1998 through July 2017. Also, the additional analysis provided in the
March 7, 2018 “Request for Written Opinion, Focused Feasibility Study and
Disproportionate Cost Analysis” addressed the Site characterization data gaps cited in the
August 31, 2017 “Further Action Opinion Letter” from Ecology.
Mr. Jimmy Blais
July 19, 2018
Page 3
Electronic submittal of all sampling data into Ecology’s electronic Environmental
Information Management (EIM) database is a requirement in order to receive a NFA
opinion from Ecology for this Site. EIM guidance can be found on the following
Ecology web page:https://ecology.wa.gov/Research-Data/Data-
resources/Environmental-Information-Management-database . Erica Fot (email
Efot461@ecy.wa.gov, telephone 360-407-6692) is Ecology’s contact and resource on
entering data into EIM.
2. Establishment of cleanup standards.
Soil
Cleanup Levels: The proposed future use of the Site (residential) does not meet the MTCA
definition of an industrial property; therefore, soil cleanup levels suitable for unrestricted
land use are appropriate. Soil cleanup levels based on protection of ground water are
appropriate. The MTCA Method A cleanup levels (TPH-G, TPH-D, and TPH-O) and
Method B cleanup levels (formaldehyde) are considered appropriate for soil at the Site and
are protective of human health and the environment.
Soil cleanup levels protective of terrestrial ecological receptors are not necessary because
the Site meets the Terrestrial Ecological Evaluation (TEE) exclusion criteria (MTCA WAC
173-340-7491). The results of the TEE Evaluation Form worksheet indicated that a TEE
exclusion is applicable and that protective cleanup levels based on TEE factors are not
required for this Site.
Point of Compliance: For soil cleanup levels based on the protection of ground water, the
point of compliance is defined as Site-wide throughout the soil profile and may extend
below the water table. This is the appropriate point of compliance for the Site.
Soil Vapor
Formaldehyde in soil vapor was evaluated as a potential vapor intrusion (VI) issue, based
on detections of this chemical in soil vapor samples conducted at the Site in 2016. This
soil vapor sampling occurred after completion of the on-site removal and in-situ treatment
of formaldehyde-contaminated soil in 2010 (see Enclosure A), after confirmation soil and
ground water sampling showed concentrations below the Method B cleanup levels.
Formaldehyde does not have soil or ground water VI screening levels in the current
Ecology VI guidance. Based on this information and data, soil vapor was eliminated as a
contaminated media for this Site.
Mr. Jimmy Blais
July 19, 2018
Page 4
Ground Water
Cleanup Levels: MTCA Method A cleanup levels for arsenic and formaldehyde are the
applicable ground water cleanup levels for this Site. A ground water cleanup level for pH
does not exist; however, the maximum reported pH value in Site ground water (12.54) was
above the characteristic dangerous waste threshold of 12.5; therefore, pH is considered to
be a water quality parameter of concern at the Site.
Point of Compliance: Ecology has determined the conditional point of compliance
proposed for ground water at the Site (western Property boundary) is appropriate for the
Site, given the following:
x Data documenting a consistent ground water flow direction away from the Cedar
River to the northwest has been provided to Ecology, and
x It is not practicable to meet the cleanup level for arsenic and an acceptable
concentration of pH in ground water throughout the Site within a reasonable
restoration time frame, per WAC 173-340(8)(c), due to presence of high pH soils
in inaccessible Site areas.
3. Selection of cleanup action.
Ecology has determined the cleanup action you proposed for the Site meets the
substantive requirements of MTCA. The focused feasibility study and disproportionate
cost analysis (Farallon Consulting 2018) documented the rationale for accepting the
interim cleanup actions as the final cleanup action. Interim cleanup actions completed to
date at the Site are summarized in Enclosure A.
The FS and DCA conclude that an environmental covenant (EC) will be required to
support a No Further Action determination for the Site, and Ecology concurs. The
environmental covenant will include an operation and maintenance (O&M) plan and a
confirmational monitoring plan.
In order to adequately monitor ground water along the western property boundary
(conditional point of compliance), Ecology will require installation of an additional
downgradient monitoring well, between existing monitoring wells MW-1 and EPI-MW-
1. Monitoring of ground water at this point of compliance is especially important
because the Site is located within the 1-year time-of-travel wellhead protection zone of
City of Renton water supply Well 8 and Well 9. These water wells are located
approximately 700 to 800 feet west of the western Property boundary.
Mr. Jimmy Blais
July 19, 2018
Page 5
Links to Ecology guidance regarding environmental covenants can be found on our web
site: https://fortress.wa.gov/ecy/publications/SummaryPages/1509054.html .
Limitations of the Opinion
1. Opinion does not settle liability with the state.
Liable persons are strictly liable, jointly and severally, for all remedial action costs and
for all natural resource damages resulting from the release or releases of hazardous
substances at the Site. This opinion does not:
x Resolve or alter a person’s liability to the state.
x Protect liable persons from contribution claims by third parties.
To settle liability with the state and obtain protection from contribution claims, a person
must enter into a consent decree with Ecology under RCW 70.105D.040(4).
2. Opinion does not constitute a determination of substantial equivalence.
To recover remedial action costs from other liable persons under MTCA, one must
demonstrate that the action is the substantial equivalent of an Ecology-conducted or
Ecology-supervised action. This opinion does not determine whether the action you
proposed will be substantially equivalent. Courts make that determination. See RCW
70.105D.080 and WAC 173-340-545.
3. Opinion is limited to proposed cleanup.
This letter does not provide an opinion on whether further remedial action will actually
be necessary at the Site upon completion of your proposed cleanup. To obtain such an
opinion, you must submit a report to Ecology upon completion of your cleanup and
request an opinion under the VCP.
4. State is immune from liability.
The state, Ecology, and its officers and employees are immune from all liability, and no
cause of action of any nature may arise from any act or omission in providing this
opinion.See RCW 70.105D.030(1)(i).
Contact Information
Thank you for choosing to clean up the Site under the Voluntary Cleanup Program (VCP). As
Enclosure A
Description and Diagrams of the Site
Site Description
This section provides Ecology’s understanding and interpretation of Site conditions, and is the
basis for the opinions expressed in the body of this letter.
Site:Stoneway Concrete is located on King County parcel 1723059026 (the Property), which
occupies 12.54 acres situated between the Cedar River and SE Maple Valley Highway (Figure
1). The Site boundaries generally follow the Property boundaries.
Site History and Current Use: Historical records indicate that the Property was developed in
the 1930s as Stoneway Dock Company. The facility name changed to Stoneway Sand and Gravel
in the 1950s. During the 1950s and 1960s, the Property was reportedly leased by many
businesses, including an asphalt manufacturing company. By 1966, the Property was owned and
operated by Stoneway Concrete and in 1985 was purchased by Don Merlino.
The Property was most recently occupied by a concrete batch plant, along with associated
support activities (Figure 2). Operations on the Property ceased prior to October 2002 in order
to conform with the City of Renton aquifer protection ordinance, which precludes industrial
activities that use, handle, or store hazardous substances in Aquifer Protection Area Zone 1.
Sources of Contamination: Petroleum hydrocarbons were detected in soil due to historic
surface spillage and historic releases from underground storage tanks that have been removed.
Formaldehyde in soil and ground water is attributed to spills of a chemical additive associated
with the concrete batch process. Arsenic, detected in ground water above the cleanup level, was
not found in soil at concentrations exceeding natural background concentrations.
Physiographic Setting: The Site is relatively flat and slopes from an elevation of 50 feet above
mean sea level (amsl) adjacent to State Route 169 on the north to 40 feet amsl at the Cedar River
on the south. The Cedar River valley is very narrow in the Site vicinity and is bounded on the
north and south by steep valley walls that attain elevations of 300 to 400 feet amsl.
Surface/Storm Water System: The majority of the Property is currently paved with concrete
that is 4 - 12 inches thick. Unpaved areas are located in the eastern and western portions of the
Property. Storm sewer control is in place in the upper portion of the Property and the Property
has a storm water permit. Storm water in the lower portion of the Property drains to on-site
settlement ponds for infiltration. There are no point source discharges to the Cedar River.
Ecological Setting: Most of the Property’s river frontage is protected with erosion control
features such as riprap, cast-in-place concrete walls, "Ecology" blocks, and a poured concrete
veneer over the native soils. Very little of the original low bank frontage remains and there does
not appear to be a riparian habitat on the Property.
Geology: The Site is underlain by coarse sands and gravels deposited in the valley of the Cedar
River. The Cedar River valley is very narrow in the Site vicinity and is bounded by steep-sided
valley walls comprised of glacial till overlying bedrock. The surface of the Site has been graded
over time and includes varying thicknesses of fill. The sand and gravel alluvium has been
observed in borings to a depth of 50 feet below ground surface (bgs), the deepest exploration on
the Site.
Ground Water: Ground water occurs under unconfined conditions in the sand and gravel
alluvium beneath the Site, in the regional, USEPA-designated Sole Source Cedar Valley Aquifer.
The City of Renton obtains the majority of the water supply from well fields in this aquifer,
located upstream and downstream from the Site. Local well logs indicate that this aquifer
extends to depths up to 72 feet bgs near the Site.
Depths to ground water at the Site range from 10 to 20 feet bgs. Data from detailed studies of
the aquifer by the City of Renton, and monitoring wells on the Site, confirm a consistent
northwesterly flow direction across the Site, away from the Cedar River. This reach of the Cedar
River loses a significant volume of surface water through the riverbed into the aquifer, resulting
in the down-valley ground water gradient to the northwest. Aquifer tests conducted in the City
of Renton wellfield (located within 700 feet northwest of the western Property boundary)
document that this prevailing ground water flow direction is not measurably affected by
pumpage in the well field.
Extent of Contamination and Remedial Actions: From 2005 through 2010, numerous
remedial actions regarding soil contamination have taken place at the Property (Figure 5), which
are summarized as follows:
x Work Area 1- Former Small Settling Pond (southwest corner of Property). High pH soil
was present in this area. At total of 200 cubic yards was removed to a depth of 6 feet,
with the southwest area excavated to 8 feet. Sixteen performance samples indicated pH
at limits of excavation (sidewalls and floor) was 6.0-8.0.
x Work Area 2 - Large Settling Ponds. The settling ponds are concrete lined and
approximately 15 feet deep. Approximately 2,200 cubic yards of high pH soil were
removed from within the settling ponds. Excavation was completed when the concrete
sidewalls and bottom were exposed. Because the Site was excavated to concrete, no
performance samples were collected. A small amount of high pH soil may remain below
and around the concrete settling ponds. Removing this material would involve
excavating in and adjacent to the Cedar River, which may pose a risk to salmon spawning
habitat and erosion of the bulkheads.
x Work Area 3 - Shallow Petroleum Impacted Area. COCs for this area were TPHo and
TPHd. Impacted soil in this area was excavated to a depth of 4 feet. Approximately 190
cubic yards of TPHo contaminated soil were removed. Twelve performance samples
indicated TPHo and TPHd were below cleanup levels (ranging from less than detection
limits to 410 mg/kg).
x Work Area 4 - Formaldehyde Impacted Area. This area is the largest on the Site and
covers a major portion of the central area of the Property. The final size of this area at the
completion of soil excavation was 1.4 acres. The depth of excavation was to
approximately 11 feet bgs. Approximately 21,000 cubic yards of material were excavated
from the area, of which 13,000 cubic yards were bioremediated on-Site and the remainder
disposed off-Site.
Performance samples were collected and areas over excavated if a performance sample
was above the formaldehyde cleanup level. A total of 447 performance samples were
collected and analyzed from this area, with 238 samples representing final performance
samples. All final performance samples were below the cleanup level.
x Work Area 5 - Heating oil UST. A 600-gallon UST was removed from this area. 300
cubic yards were removed from this area (24 feet x 24 feet) to a depth of 23 feet bgs.
During the remediation effort, approximately 3,000 gallons of water that accumulated in
the pit was removed. Eleven performance samples were collected. Only one of the
performance samples was above analytical detection levels, but below the cleanup level.
TPHd levels in the water that accumulated in the pit were 320 μg/L, below the ground
water cleanup level.
Concentrations of COCs in ground water are shown on Figure 5. As mentioned in the text of
this opinion letter, the present status of formaldehyde in ground water cannot be assessed,
because the laboratory detection limits for the most recent sampling events were greater than the
cleanup level of 5 μg/L. Elevated pH has been observed in monitoring well MW-10 since
January 2012 (ranging from 11.02 to 12.54).
Site Diagrams
Checked By: JR Disc Reference:
FARALLON PN: 266-008
SITE LOCATION
Copyright:© 2013 National Geographic Society, i-cubed
³SITE VICINITY MAP
OLD STONEWAY CONCRETE SITE
1915 SOUTHEAST MAPLE VALLEY HIGHWAY
RENTON, WASHINGTON
Washington
Issaquah | Bellingham | Seattle
Oregon
Portland | Bend | Baker City
California
Oakland | Sacramento | IrvineCONSULTING
Quality Service for Environmental Solutions | farallonconsulting.com
Farallon
Date: 4/13/2017Drawn By: pemahiser
Document Path: Q:\Projects\266 Gary Merlino\008 Old Stoneway\FIGURE 1_SITE VICINITY MAP.mxd
FIGURE 1
REFERENCE: 7.5 MINUTE USGS QUADRANGLE RENTON, WASHINGTON, DATED 2011
0 2,000
SCALE IN FEET
RENTON
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Drawn By: pemahiser Checked By: JR Date: 4/13/2017
FIGURE 2
Disc Reference:
!<
!<
!<;
!<!<;
!<
!<;
!<;
!<MAPLE VALLEY HIGHWAYCEDAR RIVERGFORMER AGGREGATE
STORAGE AREA GFORMER AGGREGATE
STORAGE AREA
GFORMER SETTLING BASINGFORMER SERVICE PIT
GFORMER WAREHOUSE G
FORMER SCALE
G
FORMER MAIN OFFICE
GFORMER BATCH PLANTGFORMER ADMIXTURE STORAGE
GFORMER SETTLING PONDG
FORMER TRUCK WASHOUTGFORMER PUMPHOUSE
G
FORMER AGGREGATE STORAGE
GFORMER WELDING
AND CARPENTER SHOP
G
FORMER TRUCK SHOP
GFORMER WASTE OIL AST
GFORMER OFFICES
MW-10
EPI-MW-7
EPI-MW-6
EPI-MW-9EPI-MW-8
EPI-MW-1
MW-41
EPI-MW-5
MW-1
Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/Airbus DS,
USDA, USGS, AeroGRID, IGN, and the GIS User Community
³SITE PLAN
OLD STONEWAY CONCRETE SITE
1915 SOUTHEAST MAPLE VALLEY HIGHWAY
RENTON, WASHINGTONCONSULTING
Quality Service for Environmental Solutions | farallonconsulting.com
Farallon
Washington
Issaquah | Bellingham | Seattle
Oregon
Portland | Bend | Baker City
California
Oakland | Sacramento | Irvine
Document Path: Q:\Projects\266 Gary Merlino\008 Old Stoneway\FIGURE 2_SITE PLAN.mxd
FARALLON PN: 266-0080200
SCALE IN FEET
LEGEND
!<MONITORING WELL (INSTALLED
BY EPI AND OTHERS)
!<;ABANDONED MONITORING WELL
APPROXIMATE SITE BOUNDARY
HISTORIC SITE FEATURES
&ODMPTVSF"
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!<!<!<;!<!<;!<!<;!<;!<CEDAR RIVERGROUNDWATERFLOW DIRECTIONMW-10(NC)EPI-MW-7(30.82)EPI-MW-6EPI-MW-9(29.93)EPI-MW-8EPI-MW-1(28.38)MW-41EPI-MW-5MW-1(28.02)28.0028.0030.5030.0028.5029.0029.5030.5030.0029.0029.5028.50³CONSULTINGChecked By: JRDisc Reference:FIGURE 3GROUNDWATER ELEVATION CONTOURS AND FLOW DIRECTION FOR SEPTEMBER 15, 2016OLD STONEWAY CONCRETE SITE1915 SOUTHEAST MAPLE VALLEY HIGHWAYRENTON, WASHINGTONQuality Service for Environmental Solutions | farallonconsulting.comFarallon060SCALE IN FEETWashingtonIssaquah | Bellingham | SeattleOregonPortland | Bend | Baker CityCaliforniaOakland | Sacramento | IrvineDate: 4/13/2017Drawn By: pemahiserDocument Path: Q:\Projects\266 Gary Merlino\008 Old Stoneway\Figure 3_Contour_pee.mxdFARALLON PN: 266-008LEGENDAPPROXIMATE SITE BOUNDARY!<MONITORING WELL (INSTALLED BY EPI AND OTHERS)!<;ABANDONED MONITORING WELL(28.38)GROUNDWATER ELEVATION (9/15/16) MEASURED IN FEETABOVE MEAN SEA LEVEL RELATIVE TO NORTH AMERICANVERTICAL DATUM 1988 (MONITORING WELL SURVEY DATAPROVIDED BY ENVIRONMENTAL PARTNERS INC.)GROUNDWATER ELEVATION CONTOUR (DASHED WHERE INFERRED)29.50GROUNDWATER FLOW DIRECTION1 " = 3,000 'MAP LOCATOR(NC)GROUNDWATER ELEVATION NOT CALCULATED. MONITORING WELL SURVEY DATA WAS NOT AVAILABLE&ODMPTVSF"
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!<!<!<;!<!<;!<!<;!<;!<CEDAR RIVERMW-10EPI-MW-7EPI-MW-6EPI-MW-9EPI-MW-8EPI-MW-1MW-41EPI-MW-5MW-1³CONSULTINGChecked By: JRDisc Reference:FIGURE 4GROUNDWATER ANALYTICAL RESULTSOLD STONEWAY CONCRETE SITE1915 SOUTHEAST MAPLE VALLEY HIGHWAYRENTON, WASHINGTONQuality Service for Environmental Solutions | farallonconsulting.comFarallon080SCALE IN FEETWashingtonIssaquah | Bellingham | SeattleOregonPortland | Bend | Baker CityCaliforniaOakland | Sacramento | IrvineDate: 4/13/2017Drawn By: shaynesDocument Path: Q:\Projects\266 Gary Merlino\008 Old Stoneway\Figure 4_gwAnalyticalData_pee.mxdFARALLON PN: 266-008LEGENDAPPROXIMATE SITE BOUNDARY!<MONITORING WELL (INSTALLED BY EPI AND OTHERS)!<;ABANDONED MONITORING WELLNOTES:DISSOLVED ARSENIC AND FORMALDEHYDE UNITS ARE IN MICROGRAMS PER LITER (g/L) pH AT 25 DEGREES CELSIUS BOLD = DENOTES CONCENTRATIONS THAT EXCEED MODEL TOXICS CONTROL ACT (MTCA) CLEANUP LEVEL. < = DENOTES ANALYTE NOT DETECTED AT OR EXCEEDING THE REPORTED LIMIT LISTED. NA = NOT APPLICABLE6/8/2009 10.827<59/29/2009 11.435.8<512/14/2009 10.347.7<53/3/2010 8.585.7<56/1/2010 11.41 4.9 169/14/2010 9.357.3<512/14/2010 9.33 4.8 <53/2/2011 8.315.2<51/27/2012 9.405.9NA5/15/2012 8.455.7<610/9/2012 8.529.7<51/17/2013 7.656.5NA4/23/2013 9.05 4.2 <57/30/2013 7.707.3NA10/21/2013 8.39 4.7 <11/23/2014 7.415.2NA7/14/2014 8.855.6<11/12/2015 8.77 3.7 <24/13/2015 7.90 4.3 67/20/2015 7.595.1<210/13/2015 8.85 4.2 <1001/13/2016 7.73 3.9 <1009/15/2016 7.75.2<100DATE pHDISSOLVED ARSENICFORMALDEHYDEEPI-MW-79/29/2009 NA6.2<512/14/2009 NA7.7<53/3/2010 NA 4.0 <56/1/2010 NA 4.8 189/14/2010 NA7.1<51/9/2012 10.2717<51/17/2013 11.946.8NA4/23/2013 11.44 3.8 <57/30/2013 11.365.9NA10/21/2013 11.696.0<11/23/2014 11.4 4.3 NA7/14/2014 11.83 4.1 <11/12/2015 11.02 2.5 <24/13/2015 11.32 2.7 87/20/2015 11.83 3.6<20001/13/2016 12.54 3.1 <1009/15/2016 11.55<100DATE pHDISSOLVED ARSENICFORMALDEHYDEMW-103/18/2009 7.29 <5 <56/8/2009 7.13 <5 <59/29/2009 7.06 <1 612/14/2009 7.74 1.1 <53/3/2010 8.04 <1.8 <56/1/2010 7.48 <1.8 <59/14/2010 7.09 <1.8 <512/14/2010 7.8 <1.8 <53/2/2011 6.65 <1.8 <55/15/2012 6.6 <1.0 NA10/9/2012 6.27 1 NA4/23/2013 7.36 <1.0 <510/21/2013 6.95 <1.0 NA1/23/2014 7.16 1.3 NA7/14/2014 6.88 <1.0 <11/12/2015 6.59 <1.0 NA4/13/2015 6.98 1.3 <47/20/2015 7.09 <1.0 <210/13/2015 6.55 <1.0 <1001/13/2015 7.19 <1.0 <1009/15/2016 7.4 <3.0 <100DISSOLVED ARSENICFORMALDEHYDEMW-1DATE pH3/18/2009 7.28 <5 <56/8/2009 6.96 <5 <59/29/2009 7.24 1.7 <512/14/2009 7.42 1.6 <53/3/2010 7.86 2.4 <56/1/2010 7.66 <1.8 <59/14/2010 7.14 2.1 <512/14/2010 7.58 <1.8 <53/2/2011 7.11 2.5 <55/15/2012 6.94 1.1 NA10/9/2012 6.43 1.4 NA4/23/2013 7.64 <1.0 <510/21/2013 7.1 1.5 NA1/23/2014 7.14 1.5 NA7/14/2014 7.24 1.6 <11/12/2015 7.65 <1.0 NA4/13/2015 6.6 <1.0 <47/20/2015 6.96 <1.0 <210/13/2015 6.52 <1.0 <1001/13/2016 7.09 1.3 <1009/15/2016 7.3 <3.0 <100DISSOLVED ARSENICFORMALDEHYDEEPI-MW-1DATE pH3/18/2009 6.46 <5 <56/8/2009 6.31 <5 <59/29/2009 6.47 <1 <512/14/2009 6.34 <1 <53/3/2010 7.72 <1 <56/1/2010 6.63 <1.8 <59/14/2010 6.75 <1.8 <5DATE pHDISSOLVED ARSENICFORMALDEHYDEEPI-MW-53/18/2009 NA NA NA6/8/2009 8.18 <5 <59/29/2009 8.30 3.8 <512/14/2009 8.22 3.9 <53/3/2010 8.16 3.9 <56/1/2010 8.19 2.8 <59/14/2010 7.96 4.4 <5DISSOLVED ARSENICFORMALDEHYDEEPI-MW-6DATE pH3/18/2009 NA NA NA6/8/2009 8.15 <5 <59/29/2009 8.36 3.9 512/14/2009 8.58 4.2 <53/3/2010 8.25 4.7 <56/1/2010 8.93 3.1 <59/14/2010 7.98 4.7 <5pHDISSOLVED ARSENICFORMALDEHYDEEPI-MW-8DATE6/8/2009 7.987.0<59/29/2009 7.955.7<512/14/2009 8.265.8<53/3/2010 8.006.6<56/1/2010 8.586.459/14/2010 8.126.6<512/14/2010 8.236.3<53/2/2011 7.997.8<51/27/2012 9.256.6NA5/15/2012 7.228.1NA10/9/2012 7.477.6<51/17/2013 8.836.6NA4/23/2013 8.535.9<57/30/2013 8.427.5NA10/21/2013 8.186.6<11/23/2014 7.35.9NA7/14/2014 8.066.0<11/12/2015 8.26 3.9 <24/13/2015 6.16 3.9 <47/20/2015 7.09 4.2 <210/13/2016 7.26 4.2 <1001/13/2016 7.24 3.1 <1009/15/2016 7.8 4.7 <100DATE pHDISSOLVED ARSENICFORMALDEHYDEEPI-MW-93/18/2009 NA NA NA6/8/2009 5.87 <5 <59/29/2009 6.65 <1 <512/14/2009 6.58 <1 <53/3/2010 7.77 <1.8 <56/1/2010 6.65 <1.8 <59/14/2010 7.11 <1.8 <5DATE pHDISSOLVED ARSENICFORMALDEHYDEMW-41&ODMPTVSF"
'JHVSF
Enclosure B
Basis for the Opinion:
List of Documents
1. March 7, 2018. Request for Written Opinion, Focused Feasibility Study and
Disproportionate Cost Analysis, Old Stoneway Renton Property, 1915 Southeast Maple
Valley Highway, Renton, Washington, VCP Project No. NW1702. Farallon Consulting.
2. August 31, 2017. Further Action Opinion Letter, Stoneway Concrete, 1915 SE Maple
Valley Highway, Renton, WA, VCP NW1702. Washington State Department of Ecology.
3. April 13, 2017. Cleanup Status and Permanent Cleanup Action, Old Stoneway Renton
Property, 1915 Southeast Maple Valley Highway, Renton, WA. Farallon Consulting.
4. August 11, 2015. Cleanup Status, Former Stoneway Concrete Batch Plant, 1915 SE
Maple Valley Highway, Renton, Washington. Environmental Partners, Inc.
5. December 29, 2011. Further Action Opinion Letter, Stoneway Concrete, 1915 SE Maple
Valley Highway, Renton, WA, VCP NW1702. Washington State Department of Ecology.
6. October 12, 2011. Interim Action Report Volume 1, Former Stoneway Batch Plant, 1915
SE Maple Valley Highway, Renton Washington, WA. Environmental Partners, Inc.
7. May 9, 2011. Further Action Opinion Letter on Interim Action Report, Stoneway
Concrete, 1915 SE Maple Valley Highway, Renton, WA, VCP NW1702. Washington
State Department of Ecology.
8. February 7, 2011. Interim Action Report, Volumes 1 and 2, Former Stoneway Batch
plant, 1915 SE Maple Valley Highway, Renton Washington, WA. Environmental
Partners, Inc.
9. April 30, 2009. Opinion on Proposed Cleanup of the following Site: Former Stoneway
Batch Plant, 1915 SE Maple Valley Highway, Renton Washington, WA, VCP NW1702.
Washington State Department of Ecology.
10. March 9, 2009. Cleanup Action Plan, Stoneway Concrete, 1915 SE Maple Valley
Highway, Renton, WA, Environmental Partners, Inc.
11. October 30, 2007. Ex Situ Soil Bioremediation Treatability Study, Stoneway Concrete,
1915 SE Maple Valley Highway, Renton, WA, Environmental Partners, Inc.
12. September 17, 2007. Interim Remedial Action Letter Report, Stoneway Concrete, 1915
SE Maple Valley Highway, Renton, WA, Environmental Partners, Inc.
13. May 5, 2006. Remedial Investigation Report, Stoneway Concrete, 1915 SE Maple Valley
Highway, Renton, WA, Environmental Partners, Inc.
14. April 17, 2001. Department of Ecology Memorandum from Joanne Polayes to file.
Discontinuation of groundwater monitoring for tetrachloroethene at Stoneway Concrete,
Renton.
15. September 20, 1998. Final Report, Stoneway Tetrachloroethene (PCE) Assessment
Renton, Washington. Pacific Groundwater Group.
Exhibit 3
Environmental Covenant, Draft 10-3-2018
1
DRAFT 10-3-2018
After Recording Return
Original Signed Covenant to:
Michael Warfel, VCP Site Manager
Toxics Cleanup Program
Washington State Department of Ecology
Northwest Regional Office
3190 160th Avenue Southeast
Bellevue, Washington 98008-5452
Environmental Covenant
Grantor:SRMRENTON LLC
Grantee:State of Washington, Department of Ecology (hereafter “Ecology”)
Brief Legal Description:POR OF SE 17-23-05 BEING KNOWN AS REV LEGAL DESC OF
EXHIBIT E OF BOUNDARY LINE AGREEMENT REC #20090112001505 APPROVED BY
CITY OF RENTON DAVID CHRISTENSEN DATED 01-22-09 SEE SURVEY
20090112900011
Tax Parcel Nos.:King County 172305-9026
Cross Reference:No Further Action Opinion at a Site, VCP Project NW1702, FSID 62244377,
CSID 2121, Stoneway Concrete Renton, 1915 Maple Valley Highway, Renton WA 98055,
Month 2018.
RECITALS
a.This document is an environmental (restrictive) covenant (hereafter “Covenant”) executed
pursuant to the Model Toxics Control Act (“MTCA”), chapter 70.105D RCW, and Uniform
Environmental Covenants Act (“UECA”), chapter 64.70 RCW.
b.The Property that is the subject of this Covenant is part or all of a MTCA site commonly
known as Stoneway Concrete Renton, Ecology Facility Site ID 62244377, Cleanup Site ID
2121, Voluntary Cleanup Program # NW1702.The Property is legally described in Exhibit A,
2
and illustrated in Exhibits B and C, both of which are attached (hereafter, “Property”). If there are
differences between these Exhibits, the legal description in Exhibit A shall prevail.
c.The Property is the subject of remedial action conducted under MTCA. This Covenant
is required because residual contamination remains on the Property after completion of remedial
actions. Specifically, the following principal contaminants remain on the Property:
Medium Principal Contaminants Present
Soil Highly alkaline pH
Groundwater Arsenic and highly alkaline pH
d.It is the purpose of this Covenant to restrict certain activities and uses of the Property to
protect human health and the environment and the integrity of remedial actions conducted at the
site. This Covenant includes the following Exhibits:
Exhibit A – Legal Description
Exhibit B – Property Map
Exhibit C – Maps Illustrating Locations of Restrictions
Exhibit D – Subordination Agreements
Exhibit E – Confirmational Groundwater Monitoring Plan
Exhibit F – Operation, Maintenance, and Contingency Plan
Records describing the extent of residual contamination, remedial actions conducted, and details
of post-remediation activities required by this Covenant are available through Ecology. This
includes the following documents:
Department of Ecology, Further Action Opinion Letter, Stoneway Concrete, 1915 SE
Maple Valley Highway, Renton, WA, VCP NW1702, August 31, 2017.
Farallon Consulting, Request for Written Opinion, Focused Feasibility Study and
Disproportionate Cost Analysis, Old Stoneway Renton Property, 1915 Southeast Maple
Valley Highway, Renton, Washington, VCP Project No. NW1702, March 7, 2018.
e.This Covenant grants Ecology certain rights under UECA and as specified in this
Covenant. As a Holder of this Covenant under UECA, Ecology has an interest in real property,
however, this is not an ownership interest which equates to liability under MTCA or the
Comprehensive Environmental Response, Compensation, and Liability Act, 42 U.S.C. § 9601 et
seq. The rights of Ecology as an “agency” under UECA, other than its’ right as a holder, are not
an interest in real property.
3
COVENANT
SRMRENTON LLC, as Grantor and owner of the Property, hereby grants to the Washington
State Department of Ecology, and its successors and assignees, the following covenants.
Furthermore, it is the intent of the Grantor that such covenants shall supersede any prior interests
the GRANTOR has in the property and run with the land and be binding on all current and future
owners of any portion of, or interest in, the Property.
Section 1. General Restrictions and Requirements.
The following general restrictions and requirements shall apply to the Property:
a. Interference with Remedial Action. The Grantor shall not engage in any activity on the
Property that may impact or interfere with the remedial action and any operation, maintenance,
inspection or monitoring of that remedial action without prior written approval from Ecology.
b. Protection of Human Health and the Environment. The Grantor shall not engage in
any activity on the Property that may threaten continued protection of human health or the
environment without prior written approval from Ecology. This includes, but is not limited to, any
activity that results in the release of residual contamination that was contained as a part of the
remedial action or that exacerbates or creates a new exposure to residual contamination remaining
immediately adjacent to the Property.
c. Continued Compliance Required.Grantor shall not convey any interest in any portion
of the Property without providing for the continued adequate and complete operation, maintenance
and monitoring of remedial actions and continued compliance with this Covenant.
d. Leases. Grantor shall restrict any lease for any portion of the Property to uses and activities
consistent with this Covenant and notify all lessees of the restrictions on the use of the Property.
e. Preservation of Reference Monuments.Grantor shall make a good faith effort to
preserve any reference monuments and boundary markers used to define the areal extent of
coverage of this Covenant. Should a monument or marker be damaged or destroyed, Grantor shall
have it replaced by a licensed professional surveyor within 30 days of discovery of the damage or
destruction.
Section 2. Specific Prohibitions and Requirements.
In addition to the general restrictions in Section 1 of this Covenant, the following additional
specific restrictions and requirements shall apply to the Property.
a. Containment of Soil.The remedial action for the Property is based on containing
contaminated soil beneath the Property, the estimated extent of which is illustrated in Exhibit C.
The Grantor shall not alter or remove all or a portion of existing or future structures on the Property
in any manner that would expose contaminated soil, result in a release to the environment of
4
contaminants, or create a new exposure pathway, without prior written approval of Ecology.
Should the Grantor propose to alter or remove all or a portion of existing or future structures so
that access to the underlying soil contamination is feasible, Ecology may require treatment or
removal of the underlying contaminated soil.
b. Containment of Groundwater.The remedial action for the Property is based on
containing contaminated groundwater beneath the Property, as illustrated in Exhibit C. Contact
with high pH groundwater in the four former concrete sedimentation basins shall be prevented by
filling the basins with clean inert material to ground surface. The Grantor shall not alter or remove
the existing structures on the Property, or construct new structures on the Property, in any manner
that would expose contaminated groundwater, result in a release to the environment of
contaminants, or create a new exposure pathway, without prior written approval of Ecology.
Should the Grantor propose activities on the Property such that access to the underlying
groundwater contamination is feasible, Ecology may require treatment or removal of the
contaminated groundwater.
c. Stormwater facilities. To minimize the potential for mobilization of contaminants
remaining in the soil on the Property, no stormwater infiltration facilities or ponds shall be
constructed within the area of the Property illustrated in Exhibit C. All stormwater catch basins,
conveyance systems, and other appurtenances located within this area shall be of watertight
construction. Three 48-inch-diameter, corrugated metal pipe (CMP) dry wells, located north of
and adjacent to the four former concrete sedimentation basins, shall be decommissioned in
accordance with WAC 173-160-381.
d. Groundwater Use. The groundwater beneath the Property shall not be extracted for any
purpose other than investigation, monitoring, or remediation performed in accordance with
requirements imposed by Ecology for the Property. Drilling of a well for any water supply purpose
on or beneath the Property is strictly prohibited. Groundwater extracted from the Property for any
purpose shall be considered potentially contaminated and any discharge of this water shall be done
in accordance with state and federal law.
e. Confirmational Groundwater Monitoring Plan.Monitoring of groundwater for the
Property shall be performed in accordance with the Confirmational Groundwater Monitoring Plan
that is attached as Exhibit E to this Covenant.
f. Operation, Maintenance, and Contingency Plan.
The integrity of the Site cleanup shall be protected in accordance with the Operation, Maintenance,
and Contingency Plan that is attached as Exhibit F to this Covenant. Any activity on the Property
that compromises the integrity of the Site cleanup (including drilling; digging; piercing with a
5
sampling device, post, stake or similar device; grading; excavation; or installation of underground
utilities) is prohibited without prior written approval by Ecology.
Section 3. Access.
a.The Grantor shall maintain clear access to all remedial action components necessary to
construct, operate, inspect, monitor and maintain the remedial action.
b.The Grantor freely and voluntarily grants Ecology and its authorized representatives, upon
reasonable notice, the right to enter the Property at reasonable times to evaluate the effectiveness
of this Covenant and associated remedial actions, and enforce compliance with this Covenant and
those actions, including the right to take samples, inspect any remedial actions conducted on the
Property, and to inspect related records.
c.No right of access or use by a third party to any portion of the Property is conveyed by this
instrument.
Section 4. Notice Requirements.
a. Conveyance of Any Interest.The Grantor, when conveying any interest in any part of the
Property, including but not limited to title, easement, leases, and security or other interests, must:
i. Provide written notice to Ecology of the intended conveyance at least thirty (30) days
in advance of the conveyance.
ii. Include in the conveying document a notice in substantially the following form, as well
as a complete copy of this Covenant:
NOTICE: THIS PROPERTY IS SUBJECT TO AN ENVIRONMENTAL
COVENANTGRANTEDTOTHEWASHINGTONSTATEDEPARTMENTOF
ECOLOGY ON [DATE] AND RECORDED WITH THE KING COUNTY
AUDITORUNDERRECORDINGNUMBER[RECORDING NUMBER]. USESAND
ACTIVITIES ON THIS PROPERTY MUST COMPLY WITH THAT
COVENANT, A COMPLETE COPY OF WHICH IS ATTACHED TO THIS
DOCUMENT.
iii.Unless otherwise agreed to in writing by Ecology, provide Ecology with a complete
copy of the executed document within thirty (30) days of the date of execution of such
document.
b. Reporting Violations.Should the Grantor become aware of any violation of this
Covenant, Grantor shall promptly report such violation in writing to Ecology.
c. Emergencies.For any emergency or significant change in site conditions due to Acts of
Nature (for example, flood or fire) resulting in a violation of this Covenant, the Grantor is
authorized to respond to such an event in accordance with state and federal law. The Grantor must
6
notify Ecology in writing of the event and response actions planned or taken as soon as practical
but no later than within 24 hours of the discovery of the event.
d. Notification procedure. Any required written notice, approval, reporting or other
communication shall be personally delivered or sent by first class mail to the following persons.
Any change in this contact information shall be submitted in writing to all parties to this Covenant.
Upon mutual agreement of the parties to this Covenant, an alternative to personal delivery or first
class mail, such as e-mail or other electronic means, may be used for these communications.
Insert Name of Corporate Officer
SRMRENTON LLC
Insert Address
Insert Phone Number
Insert Email Address
Environmental Covenants Coordinator
Washington State Department of Ecology
Toxics Cleanup Program
P.O. Box 47600
Olympia, Washington 98504-7600
360-407-6000
ToxicsCleanupProgramHQ@ecy.wa.gov
Section 5. Modification or Termination.
a.Grantor must provide written notice and obtain approval from Ecology at least sixty (60)
days in advance of any proposed activity or use of the Property in a manner that is inconsistent
with this Covenant. For any proposal that is inconsistent with this Covenant and permanently
modifies an activity or use restriction at the site:
i. Ecology must issue a public notice and provide an opportunity for the public to comment
on the proposal; and
ii. IfEcology approves of the proposal, the Covenant must be amended to reflect the change
before the activity or use can proceed.
b.If the conditions at the site requiring a Covenant have changed or no longer exist, then the
Grantor may submit a request to Ecology that this Covenant be amended or terminated. Any
amendment or termination of this Covenant must follow the procedures in MTCA and UECA and
any rules promulgated under these chapters.
c.By signing this agreement, per RCW 64.70.100, the original signatories to this agreement,
other than Ecology, agree to waive all rights to sign amendments to and termination of this
Covenant.
Section 6. Enforcement and Construction.
a.This Covenant is being freely and voluntarily granted by the Grantor.
7
b. Within ten (10) days of execution of this Covenant, Grantor shall provide Ecology with an
original signed Covenant and proof of recording and a copy of the Covenant and proof of recording
to others required by RCW 64.70.070.
c. Ecology shall be entitled to enforce the terms of this Covenant by resort to specific
performance or legal process. All remedies available in this Covenant shall be in addition to any
and all remedies at law or in equity, including MTCA and UECA. Enforcement of the terms of
this Covenant shall be at the discretion of Ecology, and any forbearance, delay or omission to
exercise its rights under this Covenant in the event of a breach of any term of this Covenant is not
a waiver by Ecology of that term or of any subsequent breach of that term, or any other term in
this Covenant, or of any rights of Ecology under this Covenant.
d.The Grantor shall be responsible for all costs associated with implementation of this
Covenant. Furthermore, the Grantor, upon request by Ecology, shall be obligated to pay for
Ecology’s costs to process a request for any modification or termination of this Covenant and any
approval required by this Covenant.
e.This Covenant shall be liberally construed to meet the intent of MTCA and UECA.
f.The provisions of this Covenant shall be severable. If any provision in this Covenant or its
application to any person or circumstance is held invalid, the remainder of this Covenant or its
application to any person or circumstance is not affected and shall continue in full force and effect
as though such void provision had not been contained herein.
g.A heading used at the beginning of any section or paragraph or exhibit of this Covenant
may be used to aid in the interpretation of that section or paragraph or exhibit but does not override
the specific requirements in that section or paragraph.
8
The undersigned Grantor warrants he/she holds the title to the Propertyand hasauthority to execute
this Covenant.
EXECUTED this ______ day of __________________, 2018.
___________________________________[SIGNATURE]
by: [PRINTED NAME]
Title: ______________________________
---------------------------------------------------------------------------------------------------------------------------
CORPORATE ACKNOWLEDGMENT
STATE OF ______________________
COUNTY OF ____________________
On this day of , 2018, I certify that
personally appeared before me, acknowledged that he/she is the
of the corporation that executed the within and foregoing instrument, and signed said instrument
by free and voluntary act and deed of said corporation, for the uses and purposes therein mentioned,
and on oath stated that he/she was authorized to execute said instrument for said corporation.
__________________________________________
Notary Public in and for the State of ______________
Residing at ________________________________
My appointment expires _____________________
9
The Department of Ecology,hereby accepts the status as GRANTEE and HOLDER of
the above Environmental Covenant pertaining to the Stoneway Concrete Renton, Ecology
Facility Site ID 62244377, Cleanup Site ID 2121, Voluntary Cleanup Program # NW1702.
STATE OF WASHINGTON
DEPARTMENT OF ECOLOGY
_________________________________[SIGNATURE]
by: [PRINTED NAME]
Title: Toxics Cleanup Program Section Manager
Dated: _____________________________
Exhibit A
LEGAL DESCRIPTION
THOSE PORTIONS OF GOVERNMENT LOTS 4, 6, AND 7, BEING A PORTION OF THE
SOUTHWEST QUARTER AND THE SOUTHEAST QUARTER OF SECTION 17,
TOWNSHIP 23 NORTH, RANGE 5 EAST, WILLAMETTE MERIDIAN, KING COUNTY
WASHINGTON, DESCRIBED AS FOLLOWS:
COMMENCING AT THE NORTHEAST CORNER OF SAID SOUTHEAST QUARTER OF
SECTION 17; THENCE NORTH 89°45'17" WEST, ALONG THE NORTH LINE OF SAID
SOUTHEAST QUARTER, A DISTANCE OF 1325.66 FEET TO THE NORTHEAST
CORNER OF SAID GOVERNMENT LOT 7; THENCE SOUTH 01°08’15" WEST, ALONG
THE EAST LINE OF GOVERNMENT LOT 7, A DISTANCE OF 561.54 FEET TO THE
SOUTHEAST CORNER OF THAT STRIP OF LAND CONVEYED TO THE CITY OF
RENTON BY DEED RECORDED UNDER RECORDING NUMBER 20070716001845,
RECORDS OF KING COUNTY, WASHINGTON AND THE POINT OF BEGINNING;
THENCE NORTHWESTERLY ALONG THE SOUTHERLY BOUNDARY OF SAID STRIP
OF LAND THE FOLLOWING COURSES AND DISTANCES:
NORTH 43°36'56" WEST A DISTANCE OF 45.84 FEET;
THENCE NORTH 45°13'07" WEST A DISTANCE OF 162.69 FEET;
THENCE NORTH 45°01'03" WEST A DISTANCE OF 71.93 FEET;
THENCE NORTH 44°48'32" WEST A DISTANCE OF 43.14 FEET;
THENCE SOUTH 44°34'17" WEST A DISTANCE OF 18.55 FEET;
THENCE NORTH 45°25'13" WEST A DISTANCE OF 97.58 FEET;
THENCE NORTH 44°37'55" EAST A DISTANCE OF 20.00 FEET;
THENCE NORTH 44°56'28" WEST A DISTANCE OF 33.44 FEET;
THENCE NORTH 44°05'34" WEST A DISTANCE OF 53.75 FEET;
THENCE SOUTH 45°14'28" WEST A DISTANCE OF 3.00 FEET;
THENCE NORTH 44°05’34" WEST A DISTANCE OF 10.00 FEET;
THENCE NORTH 45°14'28" EAST A DISTANCE OF 3.00 FEET;
THENCE NORTH 44°05’34" WEST A DISTANCE OF 58.64 FEET;
THENCE NORTH 43°03'39" WEST A DISTANCE OF 81.48 FEET;
THENCE NORTH 42°20'14" WEST A DISTANCE OF 9.80 FEET;
THENCE SOUTH 47°24'25" WEST A DISTANCE OF 3.04 FEET;
THENCE NORTH 42°28'13" WEST A DISTANCE OF 10.00 FEET;
THENCE NORTH 47°24'25" EAST A DISTANCE OF 3.02 FEET;
THENCE NORTH 42°20'15" WEST A DISTANCE OF 30.15 FEET;
THENCE SOUTH 47°56'38" WEST A DISTANCE OF 2.00 FEET;
THENCE NORTH 42°03'22" WEST A DISTANCE OF 15.04 FEET;
THENCE NORTH 47°56'38" EAST A DISTANCE OF 2.00 FEET;
THENCE NORTH 41°42'44" WEST A DISTANCE OF 52.17 FEET;
THENCE NORTH 86°11'31" WEST A DISTANCE OF 19.84 FEET TO THE
SOUTHEASTERLY BOUNDARY OF THAT PARCEL OF LAND CONVEYED TO THE
CITY OF RENTON BY DEED RECORDED UNDER RECORDING NUMBER
20060515000366, RECORDS OF KING COUNTY, WASHINGTON;
THENCE SOUTHWESTERLY, ALONG THE SOUTHEASTERLY BOUNDARY OF SAID
PARCEL AND THE SOUTHEASTERLY BOUNDARY OF THAT PARCEL OF LAND
CONVEYED TO THE CITY OF RENTON BY DEED RECORDED UNDER RECORDING
NUMBER 20060515000380 RECORDS OF KING COUNTY, WASHINGTON, ALONG THE
FOLLOWING COURSES AND DISTANCES:
SOUTH 47°51’06" WEST A DISTANCE OF 34.62 FEET;
THENCE NORTH 42°08'54" WEST A DISTANCE OF
10.48 FEET;
THENCE SOUTH 47°51'06" WEST A DISTANCE OF
3.44 FEET;
THENCE SOUTHWEST ALONG THE ARC OF A TANGENT CURVE TO THE RIGHT
HAVING A RADIUS OF 394.50 FEET THROUGH A CENTRAL ANGLE OF 04°35'00", A
DISTANCE OF 31.56 FEET.
THENCE NORTH 37°33'54" WEST A DISTANCE OF 4.50 FEET;
THENCE SOUTHWEST ALONG THE ARC OF A NON-TANGENT CURVE TO THE
RIGHT THE CENTER OF WHICH BEARS NORTH 37°33'54” WEST HAVING A RADIUS
OF 390.00 FEET THROUGH A CENTRAL ANGLE OF 18°08'11", A DISTANCE OF 123.45
FEET;
THENCE LEAVING SAID SOUTHEASTERLY BOUNDARIES SOUTH 47°51’38" WEST A
DISTANCE OF 31.45 FEET;
THENCE SOUTH 88°45'08" WEST A DISTANCE OF 251.95
FEET;
THENCE SOUTH 39°43'43" WEST A DISTANCE OF 73.20
FEET;
THENCE NORTH 78°45'32" WEST A DISTANCE OF 176.04
FEET;
THENCE SOUTH 28°17'28" WEST A DISTANCE OF 410.47 FEET, MORE OR LESS, TO
THE ORDINARY HIGH WATER LINE OF THE RIGHT BANK OF THE CEDAR RIVER;
THENCE EASTERLY, ALONG SAID ORDINARY HIGH WATER LINE, TO A POINT ON
THE EAST LINE OF SAID GOVERNMENT LOT 7 WHICH BEARS SOUTH 1°08'15"
WEST FROM THE POINT OF BEGINNING;
THENCE NORTH 01°08'15" EAST A DISTANCE OF 204.49 FEET TO THE POINT OF
BEGINNING.
COMMENCING AT THE EAST QUARTER CORNER OF SECTION 17, TOWNSHIP 23
NORTH, RANGE 5 EAST, W.M., KING COUNTY, WASHINGTON;
THENCE NORTH 89°45'17" EAST, ALONG THE NORTH LINE OF THE SOUTHEAST
QUARTER OF SAID SECTION 17, 1325.66 FEET TO THE NORTHEAST CORNER OF
GOVERNMENT LOT 7 OF SAID SECTION 17;
THENCE SOUTH 01°08'15" EAST, ALONG THE EAST LINE OF SAID LOT 7, 699.60
FEET TO THE TRUE POINT OF BEGINNING;
THENCE SOUTH 86°05'30" EAST, 8.05 FEET;
THENCE SOUTH 46°07'3" EAST, 10.07 FEET;
THENCE SOUTH 32°15'04" EAST, 9.90 FEET;
THENCE SOUTH 23°06'52" EAST, 20.37 FEET;
THENCE SOUTH 20°04'33" EAST, 10.70 FEET;
THENCE SOUTH 55°58'38" WEST, 9.81 FEET;
THENCE SOUTH 60°06'50" WEST, 10.27 FEET;
THENCE SOUTH 68°03'20° WEST, 9.72 FEET;
THENCE SOUTH 67°57’27" WEST, 8.01 FEET TO SAID EAST LINE OF
LOT 7;
THENCE NORTH 01°08'15" EAST, 61.95 FEET TO THE TRUE POINT OF
BEGINNING.
EXCEPT THAT PARCEL OF LAND THE BOUNDARY OF WHICH IS DESCRIBED AS
FOLLOWS:
COMMENCING AT THE EAST QUARTER CORNER OF SECTION 17, TOWNSHIP 23
NORTH, RANGE 5 EAST, W.M., KING COUNTY, WASHINGTON
THENCE NORTH 89°45'17" EAST, ALONG THE NORTH LINE OF THE SOUTHEAST
QUARTER OF SAID SECTION 17, 1325.66 FEET TO THE NORTHEAST CORNER OF
GOVERNMENT LOT 7 OF SAID SECTION 17;
THENCE SOUTH 01°08'15" EAST, ALONG THE EAST LINE OF SAID LOT 7, 561.54
FEET TO THE TRUE POINT OF BEGINNING;
THENCE, CONTINUING ALONG SAID EAST LINE, SOUTH 01°08'15” WEST 138.06
FEET;
THENCE NORTH 86°05'30" WEST, 3.63 FEET;
THENCE NORTH 28°28'36" WEST, 31.94 FEET;
THENCE NORTH 01°47'52" WEST, 32.22 FEET;
THENCE NORTH 00°40'25" WEST, 56.39 FEET;
THENCE NORTH 03°09'34" EAST, 24.54 FEET;
THENCENORTH03°48'48"WEST,21.14FEETTOTHESOUTHLINEOFTHATSTRIP
OF LAND CONVEYED TO THE CITY OF RENTON BY DEED RECORDED UNDER
RECORDING NUMBER 20070716001845, RECORDS OF KING COUNTY,
WASHINGTON;
THENCE SOUTH 43°36’56" EAST, ALONG SAID SOUTH LINE, 33.81 FEET TO THE
TRUE POINT OF BEGINNING
SITUATE IN THE CITY OF RENTON, COUNTY OF KING, STATE OF WASHINGTON.
Exhibit B
PROPERTY MAP
Notes (will not appear in the document)
Add Figure B-1, Property Map, including:
x Line drawing base map with scale and north arrow; aerial photo base maps do not scan
well
x Outline of Property Boundary from 7/10/2017 Boundary/Topographic Survey by D. R.
Strong Consulting Engineers
x Label: SR 169, Cedar River
x Please confirm the property/parcel boundary differences between the following maps in
the area of the four concrete sedimentation basins:
o King County parcel viewer for parcel 1723059026
o 7/10/2017 Boundary/Topographic Survey by D. R. Strong Consulting Engineers
o 3/21/2008 Revised Record of Survey for ANMARCO by Triad Associates, which
shows a claim of adverse possession for the area between the legal property
boundary and the north bank of the Cedar River
Exhibit C
MAPS ILLUSTRATING LOCATIONS OF RESTRICTIONS
Notes (will not appear in the document)
Add Figure C-1, Site Plan, including:
x Line drawing base map with scale and north arrow; aerial photo base maps do not scan
well
x Outline of Property Boundary from 7/10/2017 Boundary/Topographic Survey by D. R.
Strong Consulting Engineers Parcel boundaries
x Locations of MW-1, EPI-MW-1, EPI-MW-7, EPI-MW-9, EPI-MW-10, and a new
monitoring well to be installed between MW-1 and EPI-MW-1
x Outline of estimated area with groundwater arsenic concentrations above MTCA Method
A cleanup levels
x Outline of estimated area with groundwater pH above 8.5
x Outline of estimated area where high-pH soils remain in place
x Location of Figure C-2 cross section line
Add Figure C-2, Site Cross Section, using Figure 4 from the 3-7-2018 FFS/DCA report, with the
following modifications:
x Remove formaldehyde excavation area and formaldehyde soil and groundwater data
x Outline the estimated area with groundwater arsenic concentrations above MTCA
Method A cleanup levels
x Outline the estimated area with groundwater pH above 8.5
Exhibit D
Subordination Agreements
Notes (will not appear in the document)
Based on Ecology review of the title report, Subordination Agreements may be required from the
following entities and associated easement numbers, as listed under Schedule B, Special Exceptions, of
the Fidelity National Title Insurance Company Escrow Number 20377119-416-416 dated June 8, 2018:
Title
Insurance
Report
Schedule B
Number
Easement Grantor King County
Recording Number
Brief Description of
Easement Subject
15 Not specified 20080213002215
Notice of claim of adverse
possession
17 Not specified 2009011200505
Boundary line and
easement agreement
18 State of Washington none
Land which lies below the
line of ordinary high water
of the Cedar River
If detailed mapping of any of these easements confirms that they are not located where contaminated soil
and groundwater is present, then the requirement for a subordination agreement for that entity can be
eliminated.
SUBORDINATION AGREEMENT
KNOW ALL PERSONS, That __________, the owner and holder of that certain
_______________________________ bearing the date the _____ day of ___________, _____,
executed by ______________________________, _________________________________, and
recorded in the office of the County Auditor of ____________ County, State of Washington, on
_______________, under Auditor’s File Number ________________, does hereby agree that
said Instrument shall be subordinate to the interest of the State of Washington, Department of
Ecology, under the environmental covenant to which this Subordination Agreement is attached.
__________________________________
Signature
by: _______________________________
Printed Name
Title: ______________________________
Dated: _____________________________
CORPORATE ACKNOWLEDGMENT
STATE OF
COUNTY OF
On this day of , 20__, I certify that
personally appeared before me, acknowledged that he/she is the
of the corporation that executed the within and foregoing instrument, and signed said instrument
by free and voluntary act and deed of said corporation, for the uses and purposes therein mentioned,
and on oath stated that he/she was authorized to execute said instrument for said corporation.
___________________________________________
Notary Public in and for the State of ______________
Residing at
__________________________________
My appointment expires ______________________
Exhibit E
CONFIRMATIONAL GROUNDWATER MONITORING PLAN
Compliance groundwater monitoring will be conducted as part of the selected cleanup action.
The results of the groundwater monitoring events will be used to assess groundwater flow and
gradient, and groundwater quality at the Site to ensure that the MTCA Method A cleanup level
for arsenic is attained at the conditional points of compliance at the downgradient, northwestern
Site boundary.
The Confirmation Groundwater Monitoring Plan (CGMP) includes the following elements:
x Monitoring Locations
o MW-1, EPI-MW-1, EPI-MW-7, EPI-MW-9, EPI-MW-10, and a new monitoring well
to be installed between MW-1 and EPI-MW-1; see Figure C-1 in Exhibit C of this
Covenant
o If any of these wells must be decommissioned during Property development,
replacement monitoring wells shall be installed per WAC 173-160 standards, at the
same or similar locations approved by Ecology.
x Monitoring Data to be Collected:
o Water levels
o Samples to be tested for pH (field) and dissolved arsenic
x Monitoring Frequency
o Annually, beginning in xx 2019, for at least 5 years, the time of the first periodic
review by Ecology
o Subsequent monitoring will depend upon the results of the first periodic review.
x Sampling Procedures
o Groundwater samples will be collected in accordance with the Low Stress (Low
Flow) Purging and Sampling Procedure for the Collection of Groundwater Samples
fromMonitoring Wells dated January 19, 2010, prepared by EPA (2010).
Groundwater samples will be collected directly from thepump outlet following
stabilization ofthe geochemical parameters in accordance with theEPA (2010)
guidance for low-flow purging and sampling. Laboratory analytical results will be
uploaded to Ecology’s Environmental Information Management database.
x Reporting
o Submit report of water level measurements, sample analysis results, and a map
showing groundwater elevation contours, pH, and dissolved arsenic.
x The Grantor shall maintain clear access to the on-Property wells and protect them from
damage. The Grantor shall report to Ecology within forty-eight (48) hours of the discovery
of any damage to any monitoring well. Unless Ecology approves of an alternative plan in
writing, the Grantor shall promptly repair the damage to any of the on-Property wells and
submit a report documenting this work to Ecology within thirty (30) days of completing the
repairs.
Exhibit F
OPERATION,MAINTENANCE,AND CONTINGENCY PLAN
The Grantor shall maintain clear access to the monitoring wells and protect them from damage.
The Grantor shall report to Ecology within forty-eight (48) hours of the discovery of any damage
to any monitoring well. Unless Ecology approves of an alternative plan in writing, the Grantor
shall promptly repair the damage to any monitoring wells and submit a report documenting this
work to Ecology within thirty (30) days of completing the repairs.
The Grantor shall report to Ecology within forty-eight (48) hours of the discovery of any activity
that affects the integrity of the Site cleanup. Unless an alternative plan has been approved by
Ecology in writing, the Grantor shall promptly repair any damage to the integrity of the Site
cleanup and submit a report documenting this work to Ecology within thirty (30) days of
completing the repairs.
Exhibit 4
Review of Shoreline Stabilization Alternatives for the Cedar River
Apartments Project, in Renton, WA, October 30, 2018, Golder
Associates, Inc.
Golder Associates Inc.
18300 NE Union Hill Road, Suite 200, Redmond, Washington, USA 98052
T: +1 425 883-0777 F: +1 425 882-5498
Golder and the G logo are trademarks of Golder Associates Corporation golder.com
SRM Development (SRM) requested that Golder Associates Inc. (Golder) review available information related to
existing shoreline stabilization at a proposed site called the Cedar River Apartments Project (Project). The King
County assessor Parcel Number for the Project is 1723059026, which is generally located along the Maple Valley
highway just upstream of the intersection of Interstate 405 and the Cedar River in Renton, Washington. Our
review was limited to available studies and applicable technical documents and focused on confirming whether
bank stabilization is necessary at the site. In addition, Golder is providing preliminary input on the feasibility of
implementing bank stabilization as addressed in the Renton Municipal Code (Code) within the context of the
hierarchal alternatives process. No new technical assessments or investigations were completed as a part of this
work. Our scope includes the review as described above, a brief site visit (completed on September 4, 2018), and
development of this technical memorandum summarizing the initial conclusions and results.
1.0 BACKGROUND INFORMATION
We reviewed and/or considered the following information:
Project Site Plan, by RMA (Appendix A);
Project 100-year Flood Boundary delineation, by SRM (Appendix B);
“Cedar River Channel Migration Study”, King County Water and Land Resources Division, Department of
Natural Resources and Parks, lead author Terry Butler (now retired), dated April 2015 (available on-line at:
https://your.kingcounty.gov/dnrp/library/water-and-land/flooding/mapping/Cedar-
CMZ/Cedar_CMZ_study_&maps_April_2015.pdf);
Phone conversation with Jeanne Stypula, Managing Engineer (new contact for the Cedar River channel
migration study), King County River and Floodplain Management Section;
Historical documentation from Gary Merlino Construction Company (GMCC), the most recent batch plant
operator at the site, whereby the focus was on the historical site operations going back to the original site
operator, Stoneway Gravel Company;
Renton Municipal Code, 4-3-090 Shoreline Master Program Regulations, outlined in email from S.
Sandstrom to A. Kammereck dated October 3, 2018 (Appendix C);
TECHNICAL MEMORANDUM
DATE 10/30/2018 Project No. 18101829
TO Andy Loos
SRM Development
CC Sarah Sandstrom, The Watershed Company
FROM Andreas Kammereck, PE; Joe Mitzel, EIT EMAIL akammereck@golder.com,
jmitzel@golder.com
REVIEW OF SHORELINE STABILIZATION ALTERNATIVES FOR THE CEDAR RIVER APARTMENTS
PROJECT, IN RENTON, WA
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“Summary of Integrated Streambank Protection Guidelines”; abbreviated summary of the Integrated
Streambank Stabilization Protection Guidelines (ISPG) technical document developed by the Washington
State Department of Fish and Wildlife (WDFW) by lead authors Cramer, Bates, and Miller (Appendix D);
Project Shoreline Buffer Diagrammatic and Court Concept Plan, by SRM (Appendix E); and,
Example stream and river habitat restoration, enhancement, and bank stabilization projects (Appendix F).
2.0 SITE VISIT OBSERVATIONS
A brief site visit was completed on September 4, 2018 to observe and review riverine, fluvial geomorphic, and
floodplain conditions relative to the Project. The ground elevations throughout the parcel are generally flat and
elevated above the river active channel, generally matching the top of an existing concrete retaining wall that runs
along the rightbank (orientation looking downstream) edge of the main channel. The concrete retaining wall is
approximately 15-20 feet in height, with a vertical face extending from the general parcel ground elevation down
to river level.
Figure 2-1: View looking upstream (Left) and downstream (Right) along rightbank of the Cedar River
where it abuts the existing concrete retaining wall
The 100-year flood inundation limits (Appendix B) generally correspond with the right-bank side of the main active
channel where it runs along the concrete retaining wall on the upstream end of the project (the actual elevation is
likely somewhere along the face of the wall), and reaches further into the Project in the area around the settling
ponds (intersecting ground elevation where the site slopes away from the river and located approximately mid-
point along the river bank at the existing concrete bays). It then moves back towards the river and follows the
rightbank side of the main channel through the downstream end of the Project (elevation along the sloping bank).
Based on experience with similar projects, we assume the Ordinary High Water Mark (OHWM) follows closely
with the rightbank side of the main channel (and along the near vertical wall face).
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3.0 KING COUNTY CMZ STUDY
Review of the King County (2015) study of channel migration hazards along the Cedar river show the site is
located within an unconstrained channel migration zone (Figure 3-1) and define the channel migration zone
regulatory status covering much of the parcel as a “severe hazard area” (Figure 3-2). The unconstrained channel
migration zone does not account for the existing concrete retaining wall that runs along the rightbank side of the
channel through the parcel, which is standard of practice this these types of assessments; the term
“unconstrained” refers to the expected limits of the channel migration if no structure were there to impede the
river.
Figure 3-1: Unconstrained Channel Migration Map (Map 6, Panel 1 of 8)
Figure 3-2: Channel Migration Zone (Map 7, Panel 1 of 8)
The technical methods and approach for King County (2015) study were discussed briefly with Jeanne Stypula,
Managing Engineer in the King County River and Floodplain Management Section, who is the current point of
contact for the study because the lead author for the study has retired from the County. The approach and
methods used for the study represent the standard of practice for these type of assessments, and based on our
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review of the document and discussions with King County we do not envision that additional technical studies
would result in new or changed conclusions on the delineation of channel migration hazards for the site.
4.0 HISTORICAL SITE CONDITIONS
Historical information from the Gary Merlino Construction Company (GMCC), who was the most recent batch-
plant operator at the site, provides a summary of historical site conditions and changes in land use going back
decades for the Project site. The site was originally developed in the early 1930’s by the Stoneway Dock
Company with a concrete batch plant and rock crushing operation. The sand and gravel for the concrete batch
plant was dredged from the river. Figure 4-1 shows an aerial photo from the site in 1946. Note how the main
river channel reaches into the middle of the site in the area where the settling ponds (i.e. old concrete bays)
currently exist. Additionally, the active channel appears to be unconfined with no apparent in-channel control
structures. There appears to be gravel mining activities in the upstream portion of the site, presumably to support
the batch plant operations.
Figure 4-1: 1946 Aerial Photo
A newspaper clipping from 1954 shows an oblique view looking downstream of the site. The batch plant sits
predominately in the middle of the site and the central portion of the site has been filled and flattened. There is
evidence of a storage pond along the river edge toward the upstream end of the site. Around this time the
operating company name changed to the ‘Stoneway Sand and Gravel Company’.
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Figure 4-2: Newspaper Clipping from 1954
Figure 4-3 provides an oblique aerial view from 1961, while Figure 4-4 shows a plan view aerial photo from 1962.
At this time, the river channel ran close to the settling pond (reference photos) towards the upstream end of the
site. Comparison of the 1962 and 1977 aerial photos shows that site operations have pushed the river channel to
the south, presumably to expand the site area. Similarly, the historical channel alignment appears to have been
filled at the upstream end of the site for expansion of operations. While a long linear bank alignment through the
upstream end of the site is evident in the 1961 photo (Figure 4-3), there appears to be changes in the bank
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alignment even in the 1962 aerial photo (Figure 4-4); this may be explained by the photos showing different flow
conditions (i.e. 1962 may show lower flows that expose gravel bars along the rightbank side of the channel). No
retaining wall is evident in 1977 aerial photo (Figure 4-5).
Figure 4-3: Oblique Aerial Photo from 1961
Figure 4-4: Aerial Photo from 1962
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Figure 4-5: Aerial Photo from 1977
Figure 4-6: Aerial Photo from 1985
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Figure 4-7: Aerial Photo from 2002
Figure 4-8: Google Aerial Image from 2018
The 1985 aerial photo (Figure 4-6) shows a similar rightbank river bank alignment as the 1977 photo (Figure 4-5),
and no retaining wall is evident. By the 2002 (aerial photo Figure 4-7), the retaining wall is evident as a
pronounced line defining the rightbank side of the main river channel. Concrete mixer trucks are easily identified
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parked along the edge of the retaining wall (Figure 4-7). The bank line from 2002 appears unchanged with the
current bank line (Figure 4-8) seen in a Google Image from 2018.
5.0 RENTON MUNICIPAL CODE
SRM requested Golder look at the Renton Municipal Code (Code) with respect to bank stabilization for existing
structures (see Appendix C for highlighted Code sections for review). The Code outlines the need for repairing or
retaining bank stabilization and provides a process for prioritizing bank stabilization methods called the “Shoreline
Stabilization Alternatives Hierarchy”.
From 4-3-090F.4.c.iii.a; the Code requires a demonstrated need by “geotechnical analysis” to protect “principal
uses or structures from erosion…”. Based on review of available information and the results of the King County
(2015) study, there is a demonstrated need to protect against future erosion and scour that could threaten the
Project.
From 4-3-090F.4.a.iii.a.b.c.d.e; the Code outlines the “Shoreline Stabilization Alternatives Hierarchy”, which says
that structural stabilization measures should only be used when more natural, flexible, non-structural methods
such as vegetative stabilization and bio-engineered methods are not feasible. The alternative types and methods
of stabilization are defined in order of priority by the following hierarchy of preference (whereby (a) represents
increased priority):
(a) No Action (allow the shoreline to retreat naturally), increase building setbacks and relocate structures;
(b) Flexible defense works constructed of natural materials including measures such as soft shore
protection, bioengineering, including beach nourishment, protective berms, or vegetative stabilization;
(c) Flexible defense works, as described above, with rigid works, as described below, constructed as
protective measure at the buffer line;
(d) A combination of rigid works, as described below, and flexible defense works, as described above;
and,
(e) Rigid works constructed of artificial materials such as riprap or concrete.
The Code does not provide detailed guidance on the definition of “soft shore protection”, “bioengineering”, or
“vegetative stabilization”; based on previous project experience, we assume these references imply using bank
stabilization methods addressed and explained in state-of-the-practice guidance documents developed by the
Washington State Department of Fish and Wildlife (WDFW), such as the “Stream Habitat Restoration Guidelines”
(SHRG), dated April 2012, and available at: https://wdfw.wa.gov/publications/01374/ ); and “Integrated
Streambank Protection Guidelines” (ISPG) developed in 2002, and available at:
https://wdfw.wa.gov/publications/00046/.
An abbreviated summary of the ISPG (2002) developed by the primary authors (Cramer, Gates, and Miller) is
included in Appendix D and highlights the key components of current stream bank stabilization methods and
approaches with “selection and design of stream bank protection techniques that protect or restore aquatic and
riparian habitats” (Appendix D). The ISPG (2002) reflects the current trend and guiding principles of stream bank
stabilization work that need to be incorporated into any project planning and design effort, as follows (Appendix
D):
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x Erosion is a natural process that is essential to ecological health;
x Erosion is often exacerbated or caused by human activities;
x Causes of erosion (not just symptoms) must be solved when appropriate;
x Basin, reach, and meander belt management are essential to integrated streambank projects;
x Habitat protection must be assimilated into streambank projects;
x Mitigation sequencing must be integrated into streambank projects; and,
x Impacts to natural channel processes must be mitigated.
These guiding principles should be incorporated into project planning, design, permitting, and construction of
stream stabilization projects.
5.1 Feasibility of Hierarchal Alternatives
We understand the conceptual plan for the buffer zone along river bank is represented in the “Project Shoreline
Buffer Diagrammatic and Court Concept Plan” (Appendix E). In general, with regard to references in the
hierarchical alternatives process, we assume the reference to “flexible defense works” is consistent with the
standard-of-practice technical resources as described in ISPG (2002) and SHRG (2012) for “biotechnical bank
protection techniques” such as (but not limited to): woody plantings, herbaceous cover, soil reinforcement, riparian
buffers, coir and straw logs, bank reshaping, and buffer management. Similarly, “structural bank protection
techniques” refer to (but are not limited to): anchor points, roughness trees, large woody debris (LWD) riprap, log
toe, rock toe, crib walls, ballast, and manufactured retention systems. Additional measures such as “In-stream
flow redirection techniques” that could be used, that include (but are not limited to): groins, buried groins, barbs,
engineered debris jams (i.e. engineered log jams, a.k.a. ELJ’s), drop structures, and porous weirs.
Our initial review of these types of streambank protection measures relative to the Project and relative to the
hierarchical alternatives process finds the “No Action’ alternative is not feasible because it leaves no measures to
protect the Project area from future bank erosion, scour, and channel migration hazards.
The “Flexible Defense Works” alternative is not likely sufficient (and thereby not feasible) to establish a level of
protection commensurate with the proposed Project development, primarily because “soft” vegetative measures
assume that changes can and will occur over the long-term. The currently provided buffer zone of 100 feet is likely
not enough to provide the required offset for natural processes to occur while maintaining sufficient offset from the
developed portion of the site.
The “Flexible Defense Works with Rigid Defense Works constructed at the Buffer Line” is not likely feasible
because it would take more room than is available, i.e. there is little or no space to build streambank protection
measures landward of the buffer line, which is 100 feet offset from the river bank.
The “Combination of Rigid and Flexible Works” appears feasible and could provide the required level of
protection. This alternative would likely require much of the 100 foot buffer space to construct. This alternative
would likely include a combination of biotechnical and structural bank protection techniques as described above.
These techniques would need to be designed and constructed to meet current regulatory level-of-protection
requirements, which is typically the 100-year flood level of protection but may vary depending on the intent and
function of each component of the overall project and the level of corresponding risk. The work would likely entail
combining grading the bank area within the buffer to have a variable sloped and vegetated topography consistent
with typical floodplain regimes, LWD configured in single or multiple pieces, ELJ’s to replicate the function of
natural LWD and provide erosion and scour protection, riprap rock materials in targeted areas (mostly in bank tow
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areas), piles (steel and/or wood) to secure LWD and ELJ’s, and other structural components, or variations thereof,
needed to restore and enhance habitat and provide bank protection mitigation for expected erosion and scour
conditions. Examples of similar projects that include a combination of techniques are included in Appendix F.
These examples are presented to demonstrate there is a range of relevant applications that have been
successfully constructed in Pacific Northwest riverine systems. Please note there are numerous other project
examples out there that are applicable and would inform continued planning and discussion, and additional
planning and design would be needed to develop options that best fit the Project requirements.
The “Rigid works” alternative appears feasible, but has the lowest preference in the hierarchy of alternatives when
other alternatives (as described above) are feasible.
5.1.1 Relative Planning Level Costs
Costs should be included in feasibility review of bank stabilization alternatives for the site. Relative ranges of
costs for targeted streambank stabilization techniques are included in Table 5-1. Note, these costs are intended
for planning purposes only, to provide a relative order-of-magnitude understanding of costs. They represent low
and high unit costs from ISPG (2002) which have not been adjusted to current values. More detailed and
comprehensive costing assessments are needed to develop costs that are representative of Project site-specific
proposed stabilization measures.
Costs in Table 5-1 were developed assuming a project length of approximately 1,500 feet or approximately 0.30
mile (i.e. the approximate Project length of the bank along the rightbank side of the main channel), and consider
only materials and construction costs. Design costs including geologic assessments, geotechnical engineering
and investigations, hydrotechnical (i.e. hydrologic, hydraulic, and fluvial geomorphic) engineering, and civil design
and survey costs are not addressed.
Integrated Streambank
Protection Guidelines
Techniques (2002)
Description Estimated Cost
(Low to High)
Biotechnical bank
protection techniques
woody plantings, herbaceous cover,
sol reinforcement, riparian buffers,
coir and straw logs, bank reshaping,
and buffer management
~$40,000 to
~$200,000
Structural bank protection
techniques
anchor points, roughness trees,
riprap, log toe, rock toe, crib walls,
ballast, and manufactured retention
systems
~$100,000 to
~$200,000
In-stream flow (i.e. in the
bed or bank) redirection
techniques
groins, buried groins, barbs,
engineered debris jams (i.e. LWD and
ELJ’s), drop structures, and porous
weirs
~$200,000 to
~$2,000,000
Table 5-1: Relative Streambank Stabilization Technique Costs
Based on our experience from similar and recently completed project work, the ranges of estimated costs in Table
5-1 are likely low. Note also that some combination of biotechnical, structural, and in-stream structures may be
needed for restoration and stabilization at the Project site, so total costs could be the combination of costs for
respective techniques.
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Refer to Table 5-2 for a listing of comparable example streambank restoration and stabilization projects and
corresponding total project costs (note year of completion for adjusting costs to current value). Additional
information about the projects can be found in Appendix F, including some photographs, project location, and a
link to additional publicly available project details. The example project costs range from approximately
$600,000 to $10,000,000, which represents the likely range of work that would be required at the Project site for
habitat enhancement, restoration, and bank stabilization.
Project Cost Year Notes
Upper Washougal River $800,000 2011 60 ft logs, 160 logs installed in 2011 to restore
riverine function, spread over 5 mile reach
NF Stillaguamish $621,384 2008-2012 7 structures, 0.25 miles of streambank stabilized
and habitat restoration, 0.25 mile reach
Saxon Reach $1,180,247 2010-2013 7 structures, 0.12 miles of streambank stabilized
and habitat restoration, 0.12 mi length
Riverberry-Davis VanDellen $1,200,000 ~1995 18 structures, 0.60 miles of river bank stabilized
Hoh River Bank Stabilization $7,000,000 2004
4 mid-channel ELJs, 6 bank ELJs, and 2 ELJs
for highway embankment stabilization, over 0.25
mile reach
Lower Germany Creek
Restoration not available 2011-2012 habitat restoration, river bank stabilization
Mashel Eatonville
Restoration $1,254,992 2009-2012 21 structures, 0.12 miles of streambank
stabilized
SR 20 Skagit River $10,200,000 2014 ~1,700 dolos with LWD and ELJ's along 0.26
mile bank, river bank stabilization along highway
Table 5-2: Example Stabilization Projects
The above summarized costs provide a relative understanding for how particular measures compare. As
previously mentioned, a more comprehensive and detailed cost assessment would be needed to better define
costs for proposed site-specific measures.
5.1.2 Assessing Risk
All streambank stabilization projects have inherent risk, corresponding to the dynamics and uncertainties that
come with working in the riverine environment. Identifying, assessing, and managing those risks in the planning,
design, permitting, construction, and monitoring of streambank stabilization projects is therefore critical. Any risk
assessment for this Project should consider the following (but not limited to): the regulatory setting, costs, land
use, the likelihood of continued bank erosion and channel migration potential at the site, the feasibility and
function of proposed streambank stabilization measures, long-term performance of installed measures,
monitoring, operational requirements, riverine and riparian habitat, and public safety.
6.0 CONCLUSIONS
Review of the channel migration assessment completed by King County (2015) indicates that much of the Project
site is located within a channel migration zone. The King County (2015) study approach does not account for the
existing retaining wall, which meets the standard of practice for these types of assessments. We do not see
additional studies changing the fundamental conclusions of the County’s study.
Assessing risk in terms of bank stabilization alternatives and feasibility and costs needs to be incorporated into
the planning, design, permitting, construction, and monitoring elements of the Project.
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From a geotechnical and hydrotechnical engineering, geologic, long-term performance, and risk management
perspective, the “Combination of Rigid and Flexible Works” alternative appears feasible and would likely require
much of the 100 foot buffer space for construction. This alternative could likely be constructed landward of the
OHWM. Proposed streambank stabilization measures should incorporate principles and approaches as outlined
in SHRG (2012) and ISPG (2002), or similar applicable technical resources. A range of potential costs are
presented herein. More detailed planning, investigation, design, and cost estimate are needed to develop a site-
specific bank stabilization package.
7.0 CLOSING
Please contact the undersigned if there are any questions or comments, or if further clarification or additional
information is needed.
Joe MItzel, EIT Andreas Kammereck, PE
Engineer Principal Engineer
JM/AQK/aqk
d:\new_aqk_working\projects\temp_watershed company_cedar river\final_srm_cedar river cmz review_10302018.docx
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Appendix A
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Appendix B
CEDAR 5,9(5
100-YR FLOOD BOUNDARY
NOTES
1. 1% CHANCE ANNUAL FLOOD
DEMARCATED USING FEDERAL
EMERGENCY MANAGEMENT
AGENCY FLOOD PROFILES FOR
THE CEDAR RIVER.
1% CHANCE ANNUAL
FLOOD BOUNDARY
200'50'25'0 100'
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Appendix C
From:Sarah Sandstrom
To:Kammereck, Andreas
Subject:Renton Code sections
Date:Wednesday, October 3, 2018 10:37:29 AM
Attachments:image002.png
SRM Renton_Site_Shorline Diagrammatic_2018-09-11.pdf
Hi Andreas,
I am copying the code section we discussed below with highlights on the applicable sections. I have
also attached the diagrammatic sketch of the shoreline buffer restoration.
Let me know if you have any questions.
Thanks, Sarah
4-3-090D General Development Standards
F. Shoreline Modification
4. Shoreline Stabilization
a. General Criteria for New or Expanded Shoreline Stabilization Structures:
i. Avoidance of Need for Stabilization: The need for future shoreline stabilization should be
avoided to the extent feasible for new development. New development on steep slopes or bluffs
shall be set back sufficiently to ensure that shoreline stabilization is unlikely to be necessary during
the life of the structure, as demonstrated by a geotechnical analysis.
ii. Significant Impact to Other Properties Prohibited: The need for shoreline stabilization shall
be considered in the determination of whether to approve new water-dependent uses.
Development of new water-dependent uses that would require shoreline stabilization which causes
significant impacts to adjacent or down-current properties and shoreline areas should not be
allowed.
iii. Shoreline Stabilization Alternatives Hierarchy: Structural shoreline stabilization measures
should be used only when more natural, flexible, nonstructural methods such as vegetative
stabilization, beach nourishment and bioengineering have been determined infeasible. Alternatives
for shoreline stabilization should be based on the following hierarchy of preference:
(a) No action (allow the shoreline to retreat naturally), increase building setbacks,
and relocate structures.
(b) Flexible defense works constructed of natural materials including measures such
as soft shore protection, bioengineering, including beach nourishment, protective berms, or
vegetative stabilization.
(c) Flexible defense works, as described above, with rigid works, as described below,
constructed as a protective measure at the buffer line.
(d) A combination of rigid works, as described below, and flexible defense works, as
described above.
(e) Rigid works constructed of artificial materials such as riprap or concrete.
iv. Limited New Shoreline Stabilization Allowed: New structural stabilization measures shall
not be allowed except when necessity is demonstrated in one of the following situations:
(a) To protect existing primary structures:
(1) New or enlarged structural shoreline stabilization measures for an
existing primary structure, including residences, should not be allowed unless there
is conclusive evidence, documented by a geotechnical analysis, that the structure is
in danger from shoreline erosion caused by currents, or waves within three (3) years,
or where waiting until the need is immediate would prevent the opportunity to use
measures that avoid impacts on ecological functions. Normal sloughing, erosion of
steep bluffs, or shoreline erosion itself, without a scientific or geotechnical analysis,
is not demonstration of need. The geotechnical analysis should evaluate on-site
drainage issues and address drainage problems away from the shoreline edge before
considering structural shoreline stabilization if on-site drainage is a cause of
shoreline instability at the site in question.
(2) The shoreline stabilization is evaluated by the hierarchy in subsection
F4aiii of this Section.
(3) The shoreline stabilization structure will not result in a net loss of
shoreline ecological functions.
(4) Measures to reduce shoreline erosion in a channel migration zone (CMZ)
require a geomorphic assessment by a Washington-licensed geologist with
engineering geology or hydrogeology specialty license plus experience in conducting
fluvial geomorphic assessments. Erosion control measures are only allowed if it is
demonstrated that: the erosion rate exceeds that which would normally occur in a
natural condition; the measure does not interfere with fluvial hydrological and
geomorphologic processes normally acting in natural conditions; and the measure
includes appropriate mitigation of impacts to ecological functions associated with
the stream.
(b) New Development: In support of new development when all six (6) of the
conditions listed below apply and are documented by a geotechnical analysis:
(1) The erosion is not being caused by upland conditions, such as the loss of
vegetation and drainage.
(2) Nonstructural measures, such as placing the development further from
the shoreline, planting vegetation, or installing on-site drainage improvements, are
not feasible or not sufficient.
(3) The need to protect primary structures from damage due to erosion is
demonstrated through a geotechnical report. The damage must be caused by
natural processes, such as currents and waves.
(4) The shoreline stabilization structure is evaluated by the hierarchy in
subsection F4aiii of this Section.
(5) The shoreline stabilization structure together with any compensatory
mitigation proposed by the applicant and/or required by regulatory agencies is not
expected to result in a net loss of shoreline ecological functions.
(6) The proposed new development is not located in a channel migration
zone (CMZ).
(c) Restoration and Remediation Projects: To protect projects for the restoration of
ecological functions or hazardous substance remediation projects pursuant to chapter
70.105D RCW when both of the conditions below apply and are documented by a
geotechnical analysis:
(1) The shoreline stabilization structure together with any compensatory
mitigation proposed by the applicant and/or required by regulatory agencies is not
expected to result in a net loss of shoreline ecological functions.
(2) The shoreline stabilization structure is evaluated by the hierarchy in
subsection F4aiii of this Section.
(d) Protect Navigability: To protect the navigability of a designated harbor area when
necessity is demonstrated in the following manner by a geotechnical report:
(1) Nonstructural measures, planting vegetation, or installing on-site
drainage improvements, are not feasible or not sufficient.
(2) The shoreline stabilization structure together with any compensatory
mitigation proposed by the applicant and/or required by regulatory agencies is not
expected to result in a net loss of shoreline ecological functions.
(3) The shoreline stabilization structure is evaluated by the hierarchy in
subsection F4aiii of this Section.
v. Content of Geotechnical Report: Geotechnical analysis pursuant to this Section that
addresses the need to prevent potential damage to a primary structure shall address the necessity
for shoreline stabilization by estimating time frames and rates of erosion and report on the urgency
associated with the specific situation. The geotechnical analysis shall evaluate the need and
effectiveness of both hard and soft armoring solutions in preventing potential damage to a primary
structure. Consideration should be given to permit requirements of other agencies with jurisdiction.
vi. Stream Bank Protection Required: New or expanded shoreline stabilization on streams
should assure that such structures do not unduly interfere with natural stream processes. The
Administrator of the Department of Community and Economic Development or designee shall
review the proposed design for consistency with State guidelines for stream bank protection as it
relates to local physical conditions and meet all applicable criteria of the Shoreline Master Program,
subject to the following:
(a) A geotechnical analysis of stream geomorphology both upstream and
downstream shall be performed to assess the physical character and hydraulic energy
potential of the specific stream reach and adjacent reaches upstream or down, and assure
that the physical integrity of the stream corridor is maintained, that stream processes are
not adversely affected, and that the revetment will not cause significant damage to other
properties or valuable shoreline resources.
(b) Revetments or similar hard structures are prohibited on point and channel bars,
and in salmon and trout spawning areas, except for the purpose of fish or wildlife habitat
enhancement or restoration.
(c) Revetments or similar hard structures shall be placed landward of associated
wetlands unless it can be demonstrated that placement waterward of such features would
not adversely affect ecological functions.
(d) Revetments or similar structures shall not be developed on the inside bend of
channel banks in a stream except to protect public works, railways and existing structures.
(e) Revetments shall be designed in accordance with WDFW stream bank protection
guidelines.
(f) Groins, weirs and other in-water structures may be authorized only by Shoreline
Conditional Use Permit, except for those structures installed to protect or restore ecological
functions, such as woody debris installed in streams. A geotechnical analysis of stream
geomorphology both upstream and downstream shall document that alternatives to in-
water structures are not feasible. Documentation shall establish impacts on ecological
functions that must be mitigated to achieve no net loss.
b. Design Criteria for New or Expanded Shoreline Stabilization Structures: When any structural
shoreline stabilization measures are demonstrated to be necessary, the following design criteria
shall apply:
i. Professional Design Required: Shoreline stabilization measures shall be designed by a
qualified professional. Certification by the design professional may be required to ensure that
installation meets all design parameters.
ii. General Requirements: The size of stabilization measures shall be limited to the minimum
necessary. Use measures shall be designed to assure no net loss of shoreline ecological functions.
Soft approaches shall be used unless demonstrated not to be sufficient to protect primary
structures, dwellings, and businesses or to meet resource agency permitting conditions.
iii. Restriction of Public Access Prohibited: Publicly financed or subsidized shoreline erosion
control measures shall be ensured to not restrict appropriate public access to the shoreline except
where such access is determined to be infeasible because of incompatible uses, safety, security, or
harm to ecological functions. See public access provisions; WAC 173-26-221(4). Where feasible,
ecological restoration and public access improvements shall be incorporated into the project.
iv. Restriction of Navigation Prohibited: Shoreline stabilization should not be permitted to
unnecessarily interfere with public access to public shorelines, nor with other appropriate shoreline
uses including, but not limited to, navigation, public or private recreation and Indian treaty rights.
v. Aesthetic Qualities to Be Maintained: Where possible, shoreline stabilization measures
shall be designed so as not to detract from the aesthetic qualities of the shoreline.
vi. Public Access to Be Incorporated: Required restoration and/or public access should be
incorporated into the location, design and maintenance of shoreline stabilization structures for
public or quasi-public developments whenever safely compatible with the primary purpose. Shore
stabilization on publicly owned shorelines should not be allowed to decrease long-term public use of
the shoreline.
c. Existing Shoreline Stabilization Structures: Existing shoreline stabilization structures not in
compliance with this Code may be retained, repaired, or replaced if they meet the applicable criteria
below:
i. Repair of Existing Structures: An existing shoreline stabilization structure may be repaired
as long as it serves to perform a shoreline stabilization function for a legally established land use, but
shall be subject to the provisions below if the land use for which the shoreline stabilization structure
was constructed is abandoned per RMC 4-10-060, Nonconforming Uses, or changed to a new use.
ii. Additions to Existing Structures: Additions to or increases in size of existing shoreline
stabilization measures shall be considered new structures.
iii. Changes in Land Use: An existing shoreline stabilization structure established to serve a
use that has been abandoned per RMC 4-10-060, Nonconforming Uses, discontinued, or changed to
a new use may be retained or replaced with a similar structure if:
(a) There is a demonstrated need documented by a geotechnical analysis to protect
principal uses or structures from erosion caused by currents or waves; and
(b) An evaluation of the existing shoreline stabilization structure in relation to the
hierarchy of shoreline stabilization alternatives established in subsection F4aiii of this Section
shows that a more preferred level of shoreline stabilization is infeasible. In the case of an
existing shoreline stabilization structure composed of rigid materials, if alternatives (a)
through (c) of the hierarchy in subsection F4aiii of this Section would be infeasible then the
existing shoreline stabilization structures could be retained or replaced with a similar
structure.
iv. Waterward Replacement Prohibited for Structures Protecting Residences: Replacement
walls or bulkheads, if allowed, shall not encroach waterward of the ordinary high-water mark or
existing structure unless the residence was occupied prior to January 1, 1992, and there are
overriding safety or environmental concerns. In such cases, the replacement structure shall abut the
existing shoreline stabilization structure.
v. Restoration and Maintenance of Soft Shorelines Allowed: Soft shoreline stabilization
measures that provide restoration of shoreline ecological functions may be permitted waterward of
the ordinary high-water mark. Replenishment of substrate materials to maintain the specifications of
the permitted design may be allowed as maintenance.
vi. No Net Loss: Where a net loss of ecological functions associated with critical habitats
would occur by leaving an existing structure that is being replaced, the structure shall be removed as
part of the replacement measure.
E. Use Regulations
9. Residential Development:
a. Single Family Priority Use and Other Residential Uses: Single family residences are a priority on the shoreline
under the Shoreline Management Act (RCW 90.58.020). All other residential uses are subject to the preference for
water-oriented use and must provide for meeting the requirements for ecological restoration and/or public access.
b. General Criteria: Residential developments shall be allowed only when:
i. Density and other characteristics of the development are consistent with the Renton Comprehensive Plan
and Zoning Code.
ii. Residential structures shall provide setbacks and buffers as provided in subsection D7a of this Section,
Shoreline Bulk Standards, or as modified under subsection F1 of this Section, Vegetation Conservation.
c. Public Access Required: Unless deemed inappropriate due to health, safety, or environmental concerns, new
single family residential developments, including subdivision of land for ten (10) or more parcels, shall provide public
access in accordance with subsection D4 of this Section, Public Access. Unless deemed inappropriate due to health,
safety or environmental concerns, new multi-family developments shall provide a significant public benefit such as
providing public access and/or ecological restoration along the water’s edge. For such proposed development, a
community access plan may be used to satisfy the public access requirement if the following written findings are
made by the Administrator of the Department of Community and Economic Development or designee:
i. The community access plan allows for a substantial number of people to enjoy the shoreline; and
ii. The balance of the waterfront not devoted to public and/or community access shall be devoted to ecological
restoration.
d. Shoreline Stabilization Prohibited: New residential development shall not require new shoreline stabilization.
Developable portions of lots shall not be subject to flooding or require structural flood hazard reduction measures
within a channel migration zone or floodway to support intended development during the life of the development or
use. Prior to approval, geotechnical analysis of the site and shoreline characteristics shall demonstrate that new
shoreline stabilization is unlikely to be necessary for each new lot to support intended development during the life of
the development or use.
e. Critical Areas: New residential development shall include provisions for critical areas including avoidance,
setbacks from steep slopes, bluffs, landslide hazard areas, seismic hazard areas, riparian and marine shoreline
erosion areas, and shall meet all applicable development standards. Setbacks from hazards shall be sufficient to
protect structures during the life of the structure (one hundred (100) years).
f. Vegetation Conservation: All new residential lots shall meet vegetation conservation provisions in subsection F1
of this Section, Vegetation Conservation, including the full required buffer area together with replanting and control of
invasive species within buffers to ensure establishment and continuation of a vegetation community characteristic of
a native climax community. Each lot must be able to support intended development without encroachment on
vegetation conservation areas, except for public trains and other uses allowed within such areas. Areas within
vegetation conservation areas shall be placed in common or public ownership when feasible.
g. New Private Docks Restricted: All new subdivisions shall record a prohibition on new private docks on the face
of the plat. An area reserved for shared moorage may be designated if it meets all requirements of the Shoreline
Master Program including demonstration that public and private marinas and other boating facilities are not sufficient
to meet the moorage needs of the subdivision.
h. Floating Residences Prohibited: Floating residences are prohibited.
SARAH SANDSTROM
Senior Fisheries Biologist
750 Sixth Street South
Kirkland, WA 98033
(425) 822-5242 x209
watershedco.com
Andy Loos Project No. 18101829
SRM Development 10/30/2018
17
Appendix D
INTEGRATED STREAMBANK PROTECTION GUIDELINES
Michelle Cramer P.E.1, Ken Bates P.E. 2, Dale E. Miller3
ABSTRACT: Washington State’s Integrated Streambank Protection Guidelines provide advice for the selection and design
of streambank protection techniques that protect or restore aquatic and riparian habitats. Protecting and restoring these
habitats will provide essential functions for a healthy and productive natural system while at the same time prevent or
minimize bank erosion damage. Too often these habitats have been ignored in favor of developing or protecting other
floodplain uses and have not successfully mitigated habitat impacts. By understanding river processes, designs for
streambank protection can optimize the potential to maintain fluvial integrity and provide habitat. Natural river processes
should be integrated into selecting and designing bank protection projects. Integrated streambank protection requires a
change in the traditional approach; bank protection measures should be selected to address site- and reach-based conditions
and to avoid habitat impacts rather than automatically applying traditional methods such as riprap. This new approach allows
for consideration of other methods such as roughening a bankline, directing flow away from an eroding bank, revegetation,
floodplain management, landuse planning, maintaining riparian corridors, restoring oxbows/wetlands, relocating
infrastructures at risk, managing meander belts, and public education. It may also lead to a recommendation of not allowing
specific bank protection projects.
KEY WORDS: streambank protection, assessment, risk, habitat, mitigation, design
INTRODUCTION
The State of Washington is in the final process of developing a document entitled “Integrated Streambank Protection
Guidelines” (ISPG) (Washington Department of Fish and Wildlife, 2000) for use by a wide variety of technical and
laypersons. Integrated streambank protection is the recognition, assessment, and assimilation of erosion and channel
processes, habitat considerations, mitigation requirements, levels/types of risk, project objectives, design criteria, and
attributes of bank protection techniques. Guidance is provided on how to assess these factors and how to use the results from
the assessments to select appropriate bank protection solutions. A graphical representation of the integrated streambank
protection process is shown in Figure 1. There are a number of fundamental guiding principals that comprise integrated
streambank protection:
erosion is a natural process that is essential to ecological health;
erosion is often exacerbated or caused by human activities;
causes of erosion (not just symptoms must be solved when appropriate;
basin, reach and meander belt management are essential to integrated streambank projects;
habitat protection must be assimilated into streambank projects;
mitigation sequencing must be integrated into streambank projects; and
impacts to natural channel processes must be mitigated.
Identification of suitable bank protection treatments begins with an understanding of the specific mechanism of failure at a
project site as well as the site- and reach-based causes of bank erosion. The mechanism of failure is the physical action or
process within the bank and can be thought of as the problem you see on site. The site-and reach-based causes are what
activates the mechanism of failure. These causes may be simple and discreet, or they may be highly dependent and difficult
to separate. Table 1 lists typical mechanisms of failure and corresponding site- and reach based causes of bank erosion.
These guidelines are intended to provide a framework for the selection of techniques that promote an understanding of the
erosion problem and ultimately, innovative and habitat-friendly solutions. As such, the design process advocated here is not
linear. Developing effective, creative solutions requires a clear definition and understanding of why a bank is eroding. Once
this is understood, the art and science of integrating this information with habitat considerations, mitigation requirements,
levels/types of risk, project objectives, and design criteria can result in the selection of appropriate, habitat-friendly bank
protection treatments.
1 Senior Environmental Engineer, Washington Department of Fish and Wildlife-Habitat Program, 600 Capitol Way N. ,
Olympia, WA 98501, (360)/902-2610, cramemlc@dfw.wa.gov.
2 Chief Habitat Engineer, Washington Department of Fish and Wildlife-Habitat Program, 600 Capitol Way N. , Olympia,
WA 98501, (360)/902-2545, bateskmb@dfw.wa.gov.
3 Principal, Inter-Fluve, Inc, 25 N. Willson Ave., Suite 5, Bozeman, MT 59715, (406)/586-6926,
dale_miller@interfluve.com.
FIGURE 1. Integrated Streambank Protection Process, (ISPG)
SITE AND REACH ASSESSMENTS
Identifying suitable bank protection alternatives begins with an understanding of the specific mechanism(s) of failure as well
as the site- and reach-based causes of erosion. Correctly identifying the mechanism(s) and cause(s) of failure is critical to
selecting appropriate bank protection solutions. There are five types of mechanism of failure: general bank erosion, scour,
mass failure, subsurface entrainment, and avulsion. The cause(s) of failure can be divided into site- or reach-based causes.
At times, these causes may be difficult to ascertain, nevertheless the single cause or combined causes can be identified with
careful evaluation. Often, the reach-based causes generate site-based causes. Table 1 lists the mechanisms of failure and
site- and reach-based causes. The mechanisms and causes listed in the table may be natural or human caused or exacerbated.
A site and reach assessment should identify existing habitat conditions and the habitat potential, respectively. During site and
reach assessments, it is important to recognize that bank erosion is a natural process where essential habitat functions are
often created. For example, an overhanging bank with exposed plant roots provides cover habitat. Considering habitat
creation (or conversely, impacts to habitat) resulting from bank erosion is a critical component of site and reach assessments.
MITIGATION
Bank protection projects can create substantial impacts to fish habitats. As such, every bank protection project should be
evaluated with respect to potential mitigation requirements. Before designing a project, attempts should first be made to
avoid impacts altogether. Where impacts cannot be avoided, they should be minimized to the extent possible. Where such
impacts cannot be avoided, compensatory mitigation will be necessary. The preferred option is to: first, avoid; second,
minimize; and third, compensate for impacts.
Project Objectives
Site Assessment Risk Assessment
Assessment
Reach Assessment Habitat Assessment
Design Criteria Mitigation (avoid,
minimize, compensate)
Selection Process
(screening matrices)
Techniques
flow redirection
structural
biotechnical
internal bank drainage
avulsion prevention
channel modification
no action
Mitigation
avoid impact
minimize impact
compensate for impact
TABLE 1. Mechanisms of Failure, Site- and Reach-Based Causes
Mechanism of Failure Site-Based Causes Reach-Based Causes
General Bank Erosion Reduced vegetative bank structure
Tailout and backwater bars
Smoothed channel
Along a bend (bend scour)
Meander migration
Aggradation
reduced hydrology/increased sediment
supply
localized downstream constriction
reduced slope
confined channel
Degradation
increased hydrology/reduced sediment
supply
localized shortened channel
natural channel evolution
change in long-term watershed
hydrology
Scour
Local Scour Woody debris
Bridge pier or abutments
Boulder/outcropping
Not applicable
Constriction Scour Bridge/road approach
Existing bank feature
Large woody debris jam
Not applicable
Drop/Weir Scour Weir, ledge, or sill Not applicable
Jet Scour Lateral bar
Side-channel or tributary
Abrupt channel bend (energy sink)
Subchannels in a braided channel
Not applicable
Mass Failure Saturated soils
Increased surcharge
Loss of root structure
Removal of lateral/underlying support
Meander migration
Aggradation
reduced hydrology/increased sediment
supply
localized downstream constriction
reduced slope
confined channel
Degradation
increased hydrology/reduced sediment
supply
localized shortened channel
natural channel evolution
change in long-term watershed
hydrology
Subsurface Entrainment Groundwater seepage
Rapid drawdown
Not applicable
Avulsion/
Floodplain Erosion
Floodplain activities
Natural conditions
Aggradation
Previously relocated channel
Braided channel
Large storm event
The first priority of regulatory agencies normally is for the project to be designed so impacts are avoided. If an impact cannot
be avoided, then direct effects, such as hardening a bank, are mitigated by restoring damaged or lost ecological functions.
Indirect effects are addressed by recognizing long- and short-term impacts to the reach and mitigating for them in the design
or off-site. Indirect effects might include the loss of valuable future side-channel habitat and sources of spawning gravel and
large woody debris. These losses in habitat arise from bank hardening practices, which prevent the channel from migrating
laterally (Dillon, 1998). These impacts are most critical in undisturbed river reaches since the first bank protection project
will often promulgate more bank protection projects. They are also critical in developing watersheds where landowners
expect stream channels not to move.
RISK
Throughout the design process, it is important to understand and evaluate the many types and levels of risk associated with a
bank protection project. A risk assessment should consider both the risk of continued bank erosion and the risk associated
with the bank protection project with respect to property, habitat, and public safety. All bank protection projects contain
some level of risk. For example, a bank protection project may be effective at lower flows, but may fail as a result of a larger
flood. Likewise, the quality of fish cover habitat along an undercut, vegetated streambank may be at risk by the placement of
bank protection techniques (Peters, 1998). Low erosion risk to property and public safety deserves bank protection treatment
of comparable risk that allows the bank to continue to erode but at a more gradual, natural rate.
OBJECTIVES AND DESIGN CRITERIA
Solving a bank protection problem begins with clearly stating the objectives of a project. Objectives are typically somewhat
general or qualitative. For example, objectives may be stated as “preventing further erosion of the river along the highway”
or “stabilizing the streambank to reduce loss of cropland”. In fact, there are usually a number of objectives with differing
levels of priority. For example, either of these objectives should often include “maintaining the aesthetic qualities of a
streambank environment” or “protecting or enhancing fish habitat”.
In order to bridge objectives with selection of techniques, it is important that design criteria are established. These criteria,
considering risk and cost, and stratified according to relative priority, outline the objectives of the project and provide the
foundation for making design decisions about the specific sizes and components of bank protection techniques.
SELECTION OF TECHNIQUES
One of the most difficult but important aspects of the design process is moving from the site and reach assessments to the
selection of an appropriate solution.
Three screening matrices were developed to assist the user in the selection of bank protection treatments that:
perform adequately to meet bank protection objectives;
are appropriate with respect to mechanism(s) of failure and site-and reach-based cause(s);
are considered with an understanding of the potential impacts to habitat caused by each technique; and
are selected in order of priority that first avoid, second minimize, and lastly compensate for habitat impacts.
These matrices act progressively as selective screens, or filters, of bank protection techniques. These matrices are:
Screening Treatments Based on Site Identified Mechanism of Failure
Screening Treatments Based on Reach Identified Causes
Screening Treatments Based on Habitat Protection and Mitigation
Within each matrix, bank protection techniques are listed. Each technique is rated such that the applicability of each
technique can be considered. This consideration results in accepting or rejecting a technique within the matrix. With each
subsequent matrix, techniques are progressively “screened out”, leaving a suite of feasible techniques. Throughout the
process of identifying a technique, the question should always be posed whether the best course of action might involve none
at all.
BANK PROTECTION TECHNIQUES
Information about streambank protection techniques applicable within the State of Washington is provided in these
guidelines. The techniques have been divided into seven functional groups as shown in Table 2. For each technique, the
following information is provided in the guidelines:
Description of the technique;
Application (typical application, variations, emergency, site and reach limitations);
Effects;
Design;
Habitat considerations (mitigation requirements for the technique or mitigation benefits provided by the technique);
Risk (risk to habitat, adjacent properties, and reliability/uncertainty of the technique);
Construction considerations (material required, timing considerations, cost);
Operation and maintenance needs;
Monitoring considerations by case studies;
Examples (typical drawings, site example, description, photographs); and
References.
TABLE 2. List of bank protection techniques organized by functional group.
In-Stream Flow
Redirection
Techniques
Structural
Bank
Protection
Techniques
Biotechnical
Bank Protection
Techniques
Internal Bank
Drainage
Techniques
Avulsion and
Chute Cutoff
Prevention
Techniques
Channel
Modification
Techniques
No Action
groins
buried groins
barbs
engineered
debris jam
drop structure
porous weir
anchor points
roughness
tress
riprap
log toe
rock toe
cribwalls
ballast
manufactured
retention
system
woody
plantings
herbaceous
cover
soil
reinforcement
riparian buffer
coir and straw
logs
bank reshaping
buffer
management
chimney
drain
collector
drains
floodplain
roughness
headcut
prevention
(grade control)
floodplain
flow spreader
construct
overflow
channels
Separate
guidelines are
currently being
developed for
channel
modification
techniques.
CONCLUSIONS
Integrated bank protection is the assimilation of three factors; cause of bank failure, habitat, and risk; into the planning and
design of a streambank protection project. It is crucial to assess these factors at the onset, otherwise a bank protection project
will not likely achieve ecological and structural success. Many bank protection projects have been constructed with
consideration of no more than one of these factors, the risk of erosion. The ISPG provides guidance on: assessing site- and
reach-based processes that may be triggering erosion; identifying project objectives and design considerations; identifying
existing and potential habitat conditions; and assessing risk. One of the most difficult but important aspects of integrated
bank protection is moving from the assessment and identification of project objectives/design criteria to the selection of an
appropriate bank protection solution. Three screening matrices were developed to progressively screen-out techniques,
leaving a suite of favorable techniques. Mitigation is a crucial component to the selection of bank protection treatment.
Techniques must first be selected that avoid impacts to habitat. Only after exhausting the practicality of applying techniques
that avoid impacts, can other habitat impacting techniques be selected. These impacts must be mitigated. Detailed design
information for bank protection techniques is provided in the guidelines.
ACKNOWLEDGEMENTS
The Washington Departments of Fish and Wildlife, Ecology, and Transportation and the Washington Salmon Recovery
Funding Board jointly funded the Integrated Streambank Protection Guidelines document. Several authors jointly wrote this
document from the Washington Department of Fish and Wildlife and Inter-Fluve, Inc. The primary authors are:
Washington Department of Fish and Wildlife: Ken Bates and Michelle Cramer
Inter-Fluve Consultants, Inc: Dale Miller, Karin Boyd, Lisa Fotherby, and Todd Hoitsma
REFERENCES
Dillon, J., T. Littleton, and J. Laufle, 1998. Literature Review of Revetment and Channelization Impacts on Pacific
Northwest Aquatic Resources with Implications to Skagit River, Washington. U.S. Army Corps of Engineers, Seattle
District. Seattle, Washington, pp.10-13.
Peters R.J., B.R Missildine, and D.L. Low, 1998. Seasonal Densities Near River Banks Stabilized with Various Stabilization
Methods. U.S. Fish and Wildlife Service, Western Washington Office, Lacey, Washington, pp. 26-28.
Washington Department of Fish and Wildlife and Inter-Fluve Inc., 2000. Draft Washington State Integrated Streambank
Protection Guidelines. Olympia, Washington.
Andy Loos Project No. 18101829
SRM Development 10/30/2018
18
Appendix E
Primary access path
Secondary access connection
Public amenity opportunity
(vegetation with bench, viewpoint,
or flexible open space)
Public access node and viewpoint
Restoration planting - mixed
riparian vegetation, herbaceous
and woody shrubs
Restoration planting - clustered
tree planting
View preservation area
Rev. September 2018RENTON, WA
SRM CEDAR RIVER APARTMENTS
SHORELINE BUFFER DIAGRAMMATIC + COURT CONCEPT PLAN
© 2018, The Watershed Company, all rights reserved.
Cedar River
11111111111
111111111111111222222222222222222222222222
333333333
4444444444444444444444
44444
555
44444444444444444444
1 Existing bulkhead wall to remain
2 Lowered bulkhead wall
3 Grade separation
4 Public shared-use trail (ADA-accessible)
5 Pool (private amenity)
66 Rooftop lounge (private amenity)
7 Multi-use private plaza
8 Existing trees to remain
Private amenity opportunity
(sport court, barbecue, picnic,
courtyard, patio, or flexible open
space)
Fire truck access path (grasscrete)
Private access only
CONNECTION
TO ADJACENT
PUBLIC USES SIDEWALK
CONNECTION
666666666666
777777
8888888
Vegetated screen
Shoreline buffer (100 feet)
888888888888888888888
33333333
Andy Loos Project No. 18101829
SRM Development 10/30/2018
19
Appendix F
October 2018 F-1 18101829
f_example log jam projects_revd
Project Title: Upper Washougal River Restoration (Phases 1, 2, and 3)
Cost: $800,000
Location: Washougal River
Latitude: 45.663°
Longitude: -122.168°
Photo Source: The Columbian
http://www.columbian.com/news/2011/aug/31/Upper-washougal-river-restoration-moves-ahead/
PHOTOGRAPH 1
Logs anchored into scoured
bedrock to restore natural
fish habitat.
PHOTOGRAPH 2
Chained log anchors on
Washougal River.
October 2018 F-2 18101829
f_example log jam projects_revd
Project Title: North Fork Stillaguamish Engineered Log Jams
Cost: $ 621,384
Location: North Fork Stillaguamish River
Latitude: 48.420°
Longitude: -121.667°
Photo Source: Stillaguamish Tribe of Indians
https://secure.rco.wa.gov/prism/search/projectsnapshot.aspx?ProjectNumber=07-1737
PHOTOGRAPH 3
Newly constructed ELJ
(engineered log jam)
PHOTOGRAPH 4
Reach of Stillaguamish
where new ELJs were
installed and existing
structures repaired.
October 2018 F-3 18101829
f_example log jam projects_revd
Project Title: Saxon Reach Restoration Project
Cost: $1,180,247
Location: South Fork Nooksack River
Latitude: 48.774°
Longitude: -122.213°
Photo Source: Lummi Nation
https://secure.rco.wa.gov/prism/search/ProjectSnapshot.aspx?ProjectNumber=10-1300
PHOTOGRAPH 5
Log revetment and ELJ
looking toward Saxon
Bridge
PHOTOGRAPH 6
ELJ #3 with scour pool and
log piles
October 2018 F-4 18101829
f_example log jam projects_revd
Project Title: Riverberry-Davis VanDellen Project
Location: Nooksack River
Latitude: 48.882°
Longitude: -122.327°
Photo Source: Whatcom County
PHOTOGRAPH 7
Aerial view during
construction looking
upstream, and zoomed view
of installed LWD structures
looking downstream (post-
construction), see zoomed
view corresponding to
dashed box area.
PHOTOGRAPH 8
Aerial view during
construction looking
downstream, and zoomed
view looking downstream of
bendway weir(s) using rock
riprap and dolo materials
installed on right bank of
Nooksack, see zoomed
view corresponding to
dashed box area.
October 2018 F-5 18101829
f_example log jam projects_revd
Project Title: Hoh River Bank Stabilization Site #1
Cost: $7,000,000
Location: Hoh River
Latitude: 47.782°
Longitude: -124.261°
Photo Source: Herrera Environmental Consultants Inc.
http://www.fhwa.dot.gov/publications/publicroads/06jan/05.cfm
PHOTOGRAPH 9
Installed 4 mid-channel ELJ
structures, and armored
bank where it was attacking
the highway alignment
using riprap and logs with
rootwads and included six
ELJs along roadbank and
two smaller ELJs to prevent
erosion of the highway
embankment.
PHOTOGRAPH 10
Large spruce trees placed
between H-piles with stream
boulders and river gravel
filling in the inner matric to
add buoyancy resistance.
October 2018 F-6 18101829
f_example log jam projects_revd
Project Title: Lower Germany Creek Restoration Project (Phases 1 and 2)
Location: Germany Creek
Latitude: 46.191°
Longitude: -123.124°
Photo Source: Wild Fish Conservancy
http://wildfishconservancy.org/projects/germany-creek
PHOTOGRAPH 11
Placement of LWD as part
of bank stabilization on
Lower Germany Creek
PHOTOGRAPH 12
Less invasive measure
securing log jam structure
using large dolosse.
October 2018 F-7 18101829
f_example log jam projects_revd
Project Title: Mashel River Restoration Project
Cost: $1,254,992
Location: Mashel River
Latitude: 46.860°
Longitude: -122.270°
Photo Source: Nisqually Indian Tribe
https://secure.rco.wa.gov/prism/search/projectsnapshot.aspx?ProjectNumber=09-1393
PHOTOGRAPH 13
Log revetment and ELJ
looking toward Saxon
Bridge
PHOTOGRAPH 14
ELJ #3 with scour pool and
log piles
October 2018 F-8 18101829
f_example log jam projects_revd
Project Title: SR 20 Skagit River – CED Permanent Restoration Project
Location: Skagit River
Latitude: 48.499°
Longitude: -121.528°
Photo Source: Washington Department of Transportation (WSDOT)
http://www.flickr.com/photos/wsdot/
PHOTOGRAPH 15
Staging of dolosse
anchored to log bundles as
delivered from manufacturer
PHOTOGRAPH 16
Trackhoe with grapple
placing log and dolos
bundles for first layer of
engineered log jam
Andy Loos Project No. 18101829
SRM Development 10/30/2018
20
Page Left Intentionally Blank
Exhibit 5
Cedar River Channel Migration Study, April 2015, King County Water and
Land Resources Division.
Cedar River
Channel Migration Study
April 2015
Department of Natural Resources and Parks
King County Water and Land Resources Division
River and Floodplain Management Section
201 S. Jackson Street, Suite 600
Seattle, WA 98104
Alternate Formats Available
206-477-4800 TTY Relay: 711
Cedar River
Channel Migration Study
April 2015
Submitted by:
Terry Butler
King County Water and Land Resources Division
Department of Natural Resources and Parks
Funded by:
King County Flood Control District
King County River and Floodplain Management i April 2015
Acknowledgements
John Bethel participated in fieldwork during study preparation. Kyle Comanor provided
supported on hydrologic analyses. Jennifer Vanderhoof provided technical editing of this
report. Jeanne Stypula supervised the study and map preparation.
Citation
King County. 2015. Cedar River channel migration study. Prepared by Terry Butler and
Fred Lott. King County Department of Natural Resources and Parks, Water and Land
Resources Division. Seattle, Washington.
e
King County River and Floodplain Management ii April 2015
Table of Contents
Executive Summary............................................................................................................................................ vii
1.0 Introduction .............................................................................................................................................. 1
1.1 Statement of purpose ....................................................................................................................... 2
1.2 Report Layout ...................................................................................................................................... 2
1.3 Timeframes relevant to this study .............................................................................................. 2
1.4 Effect of landslides on channel migration ................................................................................ 2
2.0 Study area characteristics ................................................................................................................... 4
2.1 General basin characteristics ........................................................................................................ 4
2.2 Human activity and built features ............................................................................................... 4
2.3 Geology and sediment ...................................................................................................................... 7
2.3.1 Geology ............................................................................................................................................. 8
2.3.2 Sediment characteristics ........................................................................................................... 9
2.4 Flood hydrology ................................................................................................................................13
2.5 Large wood .........................................................................................................................................16
3.0 Methods ....................................................................................................................................................18
3.1 Historical and current information used in report .............................................................18
3.2 Channel Migration Zone Components......................................................................................20
3.3 Mapping criteria and methods ....................................................................................................20
3.3.1 Historical Migration Zone .......................................................................................................21
3.3.2 Avulsion Hazard Zone ..............................................................................................................21
3.3.3 Erosion Hazard Area/Erosion Setback ..............................................................................22
3.3.4 Erosion Hazard Area/Geotechnical Setback ...................................................................25
3.3.5 Disconnected Migration Area ................................................................................................26
4.0 Characteristics of Channel Migration in the Study Area ........................................................27
4.1 Channel migration processes ......................................................................................................27
4.2 Morphology of the study reaches ..............................................................................................30
4.3 Lateral channel migration rates .................................................................................................35
4.4 Spatial variation in channel migration ....................................................................................39
4.5 Temporal changes in channel migration ................................................................................40
5.0 Channel migration hazards on the Cedar River ........................................................................41
King County River and Floodplain Management iii April 2015
5.1 Delineation of channel migration hazard areas ...................................................................41
5.1.1 Historical Migration Zone .......................................................................................................41
5.1.2 Avulsion Hazard Zone ..............................................................................................................41
5.1.3 Erosion Hazard Area/Erosion Setback ..............................................................................44
5.1.4 Erosion Hazard Area/Geotechnical Setback ...................................................................46
5.1.5 Disconnected Migration Area ................................................................................................46
5.2 Channel migration hazard maps ................................................................................................47
5.3 Summary, conclusions ...................................................................................................................49
6.0 References ...............................................................................................................................................51
7.0 APPENDIX A ............................................................................................................................................54
8.0 APPENDIX B ............................................................................................................................................55
King County River and Floodplain Management iv April 2015
Figures
Figure 1. Cedar River CMZ study area location map. ........................................................................ 5
Figure 2. Cedar River construction history of publicly maintained bank armoring ............. 6
Figure 3. Percent of Cedar River riverbank length with bank armoring ................................... 7
Figure 4. Temporal changes in stage at (A) USGS gage 12119000, Cedar River at
Renton, and (B) USGS gage 12117500, Cedar River near Landsburg (from
Gendaszek et al. 2012). ............................................................................................................11
Figure 5. Change in average bed elevations, 2000 or 2003 to 2012 .........................................12
Figure 6. Reach-averaged channel gradient and channel substrate particle size
(substrate data from Perkins et al. 2002 and Gendaszek et al. 2012) ..................13
Figure 7. Annual peak flows at USGS gage 12117500 Cedar River near Landsburg ..........14
Figure 8. Cedar River flood confinement ratio, by reach, at various flow events ................16
Figure 9. Plan view schematic of Channel Migration Zone (CMZ) components.
Modified from Rapp and Abbe (2003). ..............................................................................20
Figure 10. Plan view schematic of the Erosion Hazard Area/Erosion Setback. ......................24
Figure 11. Cross-section schematic of Erosion Hazard Area/Geotechnical Setback.............25
Figure 12. Example of lateral migation on the Cedar River near RM 15.5 ................................27
Figure 13. Example of channel expansion on the Cedar River at RM 5 ......................................28
Figure 14. Example of avulsion on the Cedar River near RM 10.5 ...............................................29
Figure 15. Channel sinuosity by reach ....................................................................................................34
Figure 16. Cedar River channel migration rates using all measurements ................................37
Figure 17. Cedar River weighted-average channel migration rates, using all
measurements and eroding-only measurements .........................................................38
King County River and Floodplain Management v April 2015
Tables
Table 1. Flow discharge magnitudes, annual percent chance and recurrence
intervals. ........................................................................................................................................14
Table 2. Aerial orthophotos used or consulted in this report. ...................................................19
Table 3. Cedar River reach characteristics. .......................................................................................32
Table 4. Cedar River channel migration rates using all measurements. ...............................35
Table 5. Cedar River channel migration rates using eroding-only measurements. ..........36
Table 6. Areas mapped within the Avulsion Hazard Zone. .........................................................42
Table 7. Erosion Hazard Area/Erosion Setback widths. ..............................................................45
Table 8. Assumed barriers to channel migration. ..........................................................................47
King County River and Floodplain Management vi April 2015
Appendix A
Map 1. Publicly maintained levees and revetments
Map 2. Generalized geologic map of the study area
Map 3. Historical channels and Historical Migration Zone (HMZ)
Map 4. Elevation difference (water surface at 5,000 cfs and surface topography)
Map 5. Avulsion Hazard Zone
Map 6. Unconstrained Channel Migration Zone
Map 7. Cedar River Channel Migration Zone
Appendix B
Migration Rates in Unarmored Areas (Tables B-1 and B2, and Figures B-1 and B-2)
King County River and Floodplain Management vii April 2015
EXECUTIVE SUMMARY
The Cedar River moves, or migrates, across its floodplain. This “channel migration” can
occur gradually as the river erodes one bank and deposits sediment along the other, and it
can also occur suddenly when a channel shifts abruptly to a new location. Channel
migration represents a different type of flood hazard than inundation by overbank flow.
The area subject to channel migration hazard within a given timeframe is referred to as the
channel migration zone (CMZ).
The purpose of this study is to delineate a Cedar River CMZ and identify channel migration
hazard areas in the study area extending from Lake Washington to Cedar River Mile (RM)
22. The results of the study will directly inform the planning and development of capital
flood risk reduction projects. The CMZ map also will inform regulation of land use within
channel migration hazard areas.
Study area characteristics
The CMZ study area includes the mainstem Cedar River from Landsburg Bridge at RM 22
downstream to the mouth of the river (RM 0) in the City of Renton, plus adjacent valley
bottom floor and valley walls. Both the natural geologic setting and constructed structures
strongly influence study area characteristics.
The Cedar River within the study area is a post-glacial valley that has incised through
glacial and non-glacial deposits since the last glaciation some 13,000 years ago. Bedrock
exposures are rare but locally exert significant control on channel migration. More
commonly, the Cedar River valley walls are composed of sedimentary formations that
range from erosion-resistant to erodible. The valley bottom is composed mainly of
alluvium, which typically is loose sand and gravel deposited by the river or its tributaries,
through which the channel will migrate readily if unimpeded.
Operation of the Masonry Dam and associated waterworks upstream of the study area
since circa 1914 has altered Cedar River flows and thereby influenced channel conditions
and migration characteristics for about a century. Widespread construction in the 1960s of
levees (raised earthen berms, typically with rock armor on the river side) and revetments
(rock armor intended to prevent erosion), along with other infrastructure such as the
Cedar River Trail, SR169, and several other bridges, have resulted in armored riverbanks
along much of the study area. The effects of flow regulation and bank armoring plus
naturally erosion-resistant geology combine to constrain the potential for channel
migration in many areas. However, there continues to be active channel migration along
unarmored alluvial riverbanks.
Methods
This CMZ study and resultant map uses historical channel migration patterns and rates to
predict future channel migration hazard. Cedar River channel migration was evaluated and
mapped using information from existing studies, field observations, and analyses
King County River and Floodplain Management viii April 2015
conducted in a Geographic Information System (GIS). Historical aerial photographs dating
from 1936 through 2011, historical maps, and present-day aerial imagery, including
topography shown by LiDAR, were evaluated in GIS to map historical channels and
calculate channel migration rates.
Channel migration hazards in the Cedar River were mapped by identifying the component
parts of a CMZ as specified by the King County Channel Migration Public Rule and
consistent with Washington State Department of Ecology guidance. CMZ components are
defined in the following equation and described below.
CMZ = HMZ + AHZ + EHA – DMA
where
HMZ = Historical Migration Zone
AHZ = Avulsion Hazard Zone
EHA = Erosion Hazard Area = Erosion Setback (ES) + Geotechnical Setback (GS)
DMA = Disconnected Migration Area
The Cedar River HMZ includes the area occupied by channels from 1936 to present. The
AHZ includes areas subject to a rapid shift of channel location. The ES width was calculated
as a time period ranging from 50 years to 100 years multiplied by an average annual
channel lateral migration rate calculated individually for each study reach. A GS was
mapped where EHA/ES encounters certain erosion-resistant landforms at a 1H:1V slope
landward into that landform. The DMA was mapped to exclude areas landward of publicly
maintained artificial structures that (in incorporated areas) limit channel migration or (in
unincorporated areas) are likely to restrain channel migration and are built to an elevation
that is greater than that of the annual 1 percent flood.
Once the CMZ components were mapped and combined to delineate the outer edge of the
CMZ, severe and moderate hazard areas were identified within the overall CMZ.
This study considers the effect of channel migration on slope stability when mapping the
CMZ, but it does not consider the process by which a landslide blocks and redirects the
channel. As information is compiled and mapping methodologies defined with regard to
landslide hazard areas, CMZ mapping will be evaluated to consider necessary revisions.
Characteristics of channel migration in the study area
Channel migration occurs mainly by three processes in the Cedar River:
x Lateral migration: progressive movement of the channel across floodplain resulting from
erosion along one riverbank and deposition along the other.
x Channel expansion: channel widening resulting from erosion along both banks.
x Avulsion: an abrupt shift of the channel to new location.
The channel gradient, channel confinement, channel pattern, and riverbank materials
directly influence the type and extent of channel migration that is likely to occur. Channel
migration in the Cedar River typically is more active in a channel with moderate gradient,
King County River and Floodplain Management ix April 2015
unconfined conditions and unarmored banks than in a steeper, confined channel with
armored banks. Channel conditions through much of the study area are confined and
armored.
Average annual lateral migration rates vary from 1 foot/year to 5 feet/year in most
reaches, with the highest rates in the range of 8 feet/year. In addition to spatial variation
in channel migration resulting from factors described above, the channel pattern has
simplified and channel migration rates have decreased through time because of flow
regulation since 1914 and widespread installation of bank armoring in the 1960s.
Delineation of the CMZ and channel migration hazard areas within the CMZ
An unconstrained CMZ was mapped as the combination of the HMZ + AHZ + EHA (including
EHA/ES and EHA/GS). The unconstrained CMZ does not recognize artificial constraints and
therefore predicts channel migration in the absence of levees, revetments, and
infrastructure. In a majority of study reaches, the width of the HMZ constitutes most of the
width of the unconstrained CMZ.
The unconstrained CMZ was modified in two ways to produce the CMZ map. First, the DMA
was mapped to recognize that certain artificial structures can restrain channel migration.
All publicly maintained structures in the City of Renton were mapped as barriers to
migration, as were SR 169 and sole-access roads within King County. The majority of levees
and revetments maintained by King County within unincorporated King County were not
mapped as barriers to channel migration because they were not built higher than the
elevation of the annual 1 percent chance flood and were not likely to restrain channel
migration. No privately maintained structures were mapped as barriers to channel
migration.
A second modification to the unconstrained CMZ was that severe and moderate hazard
areas were mapped within the overall CMZ. Severe hazard areas are composed of the entire
HMZ, severe AHZs, and typically half of the EHA. The present-day active channel always is
mapped as a severe hazard area. With these components mapped as severe hazards, the
severe hazard area occupies most of the width of the CMZ throughout the study area. The
moderate hazard area lies between the severe hazard area and the outer boundary of the
unconstrained CMZ. The result of these two modifications to the unconstrained CMZ
completes the Cedar River CMZ map.
Key findings and conclusions
Modifications to the Cedar River flow regime since circa 1914, coupled with widespread
bank armoring since the 1960s, combine to simplify channel pattern, confine channel
conditions, and decrease channel migration rates. With flow regulation assumed to
continue as it has for the past century, channel confinement and bank armoring emerge as
the prominent variables presently affecting channel migration in this study area. Channel
migration does occur in confined and armored areas, though at lower rates than in
King County River and Floodplain Management x April 2015
unconfined or unarmored areas. However, the potential for active channel migration
remains high should bank armoring fail or be removed.
In the few areas that are naturally unconfined or recently have had bank armoring
removed, lateral migration rates typically are higher than in confined or armored areas. A
multiple-channel pattern prevails and gravel bars are bare and active, all of which suggest
sediment deposition. Greater numbers of large wood exist in unconfined areas than in
confined areas and conditions that favor avulsion may be present. Channel expansion
typically occurs after a triggering event such as avulsion or levee removal.
The Cedar River CMZ includes most of the valley floor in the naturally confined upstream
part of this study area (Reaches 20 through 18). Further downstream, the CMZ includes
most of the valley floor where it is not cut off by major infrastructure (e.g., SR 169) in
reaches that exhibit historically active channel migration or are subject to avulsion hazards,
or both (Reaches 15, 12, 10, 9, 8, 6 and 4). The CMZ along most of the length of other
reaches covers a relatively narrow portion of the valley floor.
In addition to using the Cedar River CMZ map to regulate land use in affected channel
migration hazard areas, the CMZ map and findings of this study will inform planning and
development of capital flood risk reduction projects via the Cedar River Corridor process.
There is potential to decrease flood risk and increase floodplain connectivity in mapped
channel migration hazard areas by acquiring at-risk properties, removing constructed bank
armoring and allowing channel migration to proceed in a less constrained condition than
currently exists. This potential would be greatest in areas where channel gradient is
moderate and naturally erosion-resistant riverbanks are absent or do not dominate. Such
conditions exist in Reaches 16, 15, 12, 11, 10, 7, 6, 5 and 4 of this study area.
This study is based on the use of historical information to predict future hazard; these
methods are consistent with accepted practices and guidance from the Washington State
Department of Ecology. Because some factors affecting channel migration are stochastic in
nature, the channel may not occupy all parts of the mapped CMZ within the next 100 years.
Furthermore, the channel could occupy portions of the valley floor beyond the limits of the
mapped CMZ within the next 100 years. To recognize the need to have hazard mapping
reflect more near-term, expected conditions, it is intended that a CMZ map be updated
every 20 years. Also, portions of a CMZ map may be revised at timeframes shorter than 20
years if local changed conditions warrant.
King County River and Floodplain Management 1 April 2015
1.0 INTRODUCTION
The Cedar River moves, or migrates, across its floodplain. This “channel migration” can
occur gradually as the river erodes one bank and deposits sediment along the other, and it
can also occur suddenly when a channel shifts abruptly to a new location. Abrupt channel
changes may happen during a single flood event.
Channel migration represents a different type of flood hazard than inundation by overbank
flow. It can endanger properties located outside of the regulatory floodplain shown on
flood hazard and flood insurance maps. Although both channel migration and flood
inundation are hazards that may result from flooding, there is no specific correlation
between the mapped boundaries of these two distinct hazard areas. The area subject to
channel migration hazard within a given timeframe is referred to as the channel migration
zone (CMZ). There is a potential hazard to permanent structures anywhere within a CMZ.
The historical approach to addressing potential damage from bank erosion and channel
migration has been to armor the riverbanks with levees or revetments. However, such
bank armoring can be expensive to construct and is subject to ongoing flood damage, which
requires costly recurring maintenance work. Bank armoring can aggravate flooding or
erosion problems upstream or downstream of the armored location and degrade aquatic
habitat. In order to prevent future development in areas subject to channel migration, the
King County Flood Hazard Management Plan Update (“Flood Plan”) (King County 2013)
states in Policy FP-2:
King County should identify channel migration hazard areas through
geomorphic analyses and review of historical channel migration patterns and
rates. Land-use regulations shall restrict unsafe development in identified
channel migration hazard areas.
The Flood Plan and its policies are incorporated into the King County Comprehensive Plan
(King County 2012). These King County policies and their implementation are consistent
with State Shoreline provisions, which require the mapping of CMZs (WAC 173-26-221)
and State Department of Ecology guidance on CMZ mapping (Department of Ecology
Shorelands and Environmental Assistance Program 1994-2014; referred to herein as
“Ecology 1994-2014”).
This study constitutes the geomorphic analyses recommended in King County Flood Plan
Policy FP-2. The Cedar River CMZ map produced by this study will be provided to King
County Department of Permitting and Environmental Review (DPER) for adoption via the
2014 Revised King County Channel Migration Public Rule (King County 2014) to use in
regulating land use within channel migration hazard areas.
King County River and Floodplain Management 2 April 2015
1.1 Statement of purpose
The purpose of this study is to delineate a Cedar River CMZ and identify channel migration
hazard areas in the study area extending from Lake Washington to River Mile (RM) 22.
The Cedar River CMZ map and study utilizes historic channel information, and the resultant
hazard mapping portrays expected channel movement over time. The results of the study
will directly inform the planning and development of capital flood risk reduction
projects. For the Cedar River, this study is particularly timely for corridor planning now
underway. River corridor planning and the development of capital projects serve to
implement the policies and recommendations of the King County Flood Plan. The CMZ map
also will inform regulation of land use within channel migration hazard areas. These uses of
the Cedar CMZ map and study are consistent with county and state policies and regulations
cited on page 1.
1.2 Report Layout
This Cedar River channel migration study provides an overview of geomorphic, geologic,
physical, and structural factors affecting channel migration in the study area. Mapping
methods and criteria are described in detail. Historical channel migration patterns and
rates are evaluated as the basis of predicting future channel migration hazard. Finally,
channel migration hazard areas are identified in a channel migration zone map.
1.3 Timeframes relevant to this study
A CMZ is defined as the area through which channel migration is predicted to occur within
a given timeframe (Ecology 1994-2013; Rapp and Abbe 2003). The timeframe used in this
study to map channel migration hazard is 100 years. That timeframe is consistent with
planning timeframes used in Federal Emergency Management Agency (2013) and National
Marine Fishery Service (2008) and the adopted policies of the King County 2006 Flood Plan
and 2013 Update and Progress Report.
Although the information and methods used in this study constitute the best available
science, channel migration is a dynamic process, and the CMZ maps now prepared may
become less informative or obsolete in the distant future (i.e., 100 years). To recognize the
need to have hazard mapping reflect more near-term, expected conditions, the King County
Channel Migration Public Rule (King County 2014) requires that a CMZ map should be
updated every 20 years. As such, 20 years can be considered the planning horizon for this
CMZ study. Also, the Public Rule provides that portions of a CMZ map may be revised at a
shorter timeframe than 20 years if locally changed conditions affect channel migration,
such as construction of a levee setback project.
1.4 Effect of landslides on channel migration
The process by which a landslide blocks and redirects the channel is not addressed in this
study or CMZ maps, and CMZ mapping methods do not include technical methods to
account for landslide processes that may block or redirect the channel. As information is
King County River and Floodplain Management 3 April 2015
compiled and mapping methodologies defined with regard to landslide hazard areas, CMZ
mapping will be evaluated to consider necessary revisions.
King County River and Floodplain Management 4 April 2015
2.0 STUDY AREA CHARACTERISTICS
The Cedar River flows from headwaters in the Cascade Mountains to its mouth at the south
end of Lake Washington, as shown in Figure 1. The CMZ study area includes the length of
mainstem Cedar River from Landsburg Bridge at River Mile (RM) 22.1 downstream to the
mouth of the river (RM 0) in the City of Renton. The width of the study area includes the
valley bottom floor and valley walls along the length of the study area.
2.1 General basin characteristics
The crest of the Cascade Mountains forms the eastern border of the Cedar River basin at
elevations in excess of 5,000 feet. The Cedar River flows west for 45 miles from its
headwaters to its mouth and drains about 196 square miles. From its headwaters, it
descends through the steep, heavily forested City of Seattle's Cedar River Municipal
Watershed for over half its length. Masonry Dam impounds flow at RM 37 in Chester Morse
Lake (Figure 1). The City of Seattle operates the dam primarily for water supply and power
generation. The river flows through a steep and confined reach between Chester Morse
Lake and Landsburg. Flow is diverted at the Landsburg Diversion Dam at RM 22.6 for water
supply.
Unincorporated King County areas downstream of Landsburg through Maple Valley to the
City of Renton boundary are typified by rural residential and suburban land use of varying
densities. The lowest five miles of the river and its floodplain are almost entirely within the
City of Renton and its urban growth boundary. This area contains parks, single- and multi-
family residential development, several major subdivisions, significant commercial/
industrial development, and portions of the downtown business core. Much of the area is
developed area and supports infrastructure in close proximity to the Cedar River.
The location of this study area within the Puget Sound lowland area affected by multiple
glaciations and the geomorphic response since retreat of glaciation strongly influence basin
characteristics relevant to channel migration, as described in Section 2.3.1.
2.2 Human activity and built features
Early land uses in the Cedar River valley included the extraction industries of coal mining
and timber harvesting. Construction of a railroad up the valley in the late 19th century
spurred those activities. Masonry Dam and associated waterworks were constructed by
City of Seattle for water and power supply in the early 20th century. The entire basin
upstream of Landsburg was preserved in the City of Seattle’s municipal watershed.
The Cedar River valley downstream of Landsburg within the study area remained largely
rural through the first half of the last century. Subsequently, low-density rural land use
transitioned to areas of moderate or higher density residential use resulting in greater
numbers of structures built in areas subject to flooding and channel migration. With the
increase of population and structures in flood hazard areas, levees and revetments were
King County River and Floodplain Management 5 April 2015
Figure 1. Cedar River CMZ study area location map.
King County River and Floodplain Management 6 April 2015
constructed along the river channel. In addition to inhibiting flooding, levees and
revetments also constrain channel migration.
Levees (raised earthen berms, typically with rock armor on the river side) and revetments
(rock armor intended to prevent erosion) can inhibit or constrain channel migration. There
are approximately 70 publicly maintained levees and revetments, built as flood protection
facilities, along the Cedar River’s banks within the study area. King County maintains
facilities upstream of I-405 (RM 1.63); the City of Renton maintains the system of levees
and floodwalls downstream of I-405. The locations and approximate construction dates of
these facilities are shown in Map 1, Appendix A.
The majority of the publicly constructed and maintained flood protection facilities within
the study area were built in the 1960s with public funds raised by two King County bond
issues (Figure 2). No new bank armoring facilities have been constructed within the King
County part of the study area in the last few decades, although maintenance and repairs of
existing facilities is ongoing. Most facilities are either revetments or “training levees,” the
latter of which typically do not contain large flood flows but instead train or direct the flow
of the river.
Figure 2. Cedar River construction history of publicly maintained bank armoring.
The lowest mile of the Cedar River was rerouted to its current location and both riverbanks
were lined by armored levees in 1914. Presently, a combination of floodwalls and armored
levees, termed the Cedar River 205 Flood Control Project, provide containment of 12,000
cubic feet per second (cfs) (the annual 1 percent flood) from I-405 to the mouth. The 205
Flood Control Project also prevents channel migration of the Cedar River through the same
area.
0%
5%
10%
15%
20%
25%
30%
35%
40%
45%
50%
pre-1936 1936-1958 1959-1963 1964-1969 1970-1979 1980-2011Percent of river length in revetments Time Period
Percent built Cumulative percent armored
King County River and Floodplain Management 7 April 2015
The fill prism and bridges of a former railroad line dating from the late 1800s extend
through almost the entire length of the study area and now serve as the Cedar River Trail
(CRT). Separate CRT bridges cross the river at three locations upstream of Maple Valley
(RM 15) and three locations downstream of Maple Valley in tandem with SR169 bridges
(Map 1, Appendix A). In all, there are 18 bridges that span the Cedar River from I-405
upstream with abutments that, to some extent, fix the river channel in place. From
Landsburg to I-405, either the CRT alone or the CRT and SR169 disconnect the Cedar River
from its floodplain in several locations.
Considerable amounts of infrastructure (i.e., roads, bridges, utilities, and bank armoring)
exist in close proximity to the Cedar River through much of this study area. Some individual
segments of the Cedar River are armored extensively, and publicly maintained levees or
revetments line the majority of the length of at least one bank in about half of the reaches
of the study area (Figure 3). This percentage is higher when privately constructed bank
armoring and infrastructure are included. Almost every outside bend of the Cedar River
from Landsburg to the mouth is either armored by levees or revetments or bounded by an
erosion-resistant geologic feature (Section 2.3). Together, constructed roads, bank
armoring, and bridges plus naturally erosion-resistant geology combine to constrain the
potential for channel migration in many parts of this study reach.
Figure 3. Percent of Cedar River riverbank length with bank armoring.
2.3 Geology and sediment
The Cedar River basin is underlain by Tertiary volcanic and sedimentary bedrock that is
exposed rarely in the study area and exerts little influence on fluvial processes relevant to
channel migration on the basin scale. Locally, bedrock walls exert significant control on
channel migration. Multiple episodes of continental glaciation extending down from British
Columbia covered the Puget Lowland over the past 2.5 million years and shaped the
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
1 2 3 4 5 6 7 8 9 1011121314151617181920Percent of reach length armored Reach
Infrastructure
Private Bank Armor
Public Bank Armor
King County River and Floodplain Management 8 April 2015
landscape of today. Today, most of the Cedar River basin from Landsburg to the mouth has
valley walls composed of glacial and non-glacial sediments and a valley bottom of young
alluvium. A generalized geologic map of the study area is shown in Map 2, Appendix A
(after Mullineaux 1970 and Booth 1995).
The Cedar River within the study area has incised through glacial and non-glacial deposits
since the last glaciation some 13,000 years ago. The Cedar River in the study area is an
east-west trending, post-glacial, Holocene valley that joins a north-south trending glacial
trough, now occupied by Lake Washington, carved by direct glacial contact (Collins and
Montgomery 2011).
As a result of its geologic past, the river flows through a floodplain of erodible alluvial
materials composed primarily of sediments eroded from glacial and non-glacial deposits. If
unconstrained, the river typically will migrate laterally through young alluvium of the
modern floodplain, older alluvium of abandoned flood terrace deposits, as well as exposed
colluvium, alluvial fans, and modified fill. The river more slowly erodes relatively erosion-
resistant cliffs by undermining and cliff retreat processes, as is evident in several locations
in this study area (Perkins et al. 2002). In the few places where Tertiary bedrock forms the
valley walls, no bank erosion or channel migration is evident during timeframes relevant to
this study.
2.3.1 Geology
The following paragraphs describe geologic formations observed in river banks and valley
walls of the study area, in order from oldest to youngest.
Tertiary bedrock in the Puget Group (map unit Tp) is exposed near the middle of the
study reach and again along the south valley wall near the downstream end of the valley.
This sedimentary rock dates from the upper Eocene (some 38 million years ago) and
consists of sandstone with interbedded shale and coal. Members of the Puget Group within
the study area are the Renton Formation (Tpr) and Tertiary sedimentary (Ts) rock. The
Renton Formation outcrops on both sides of the river from RM 9 to RM 10. This outcrop
along both valley walls likely results in the narrowness of the floodplain in that area. The
south valley wall from about RM 3.9 to RM 2.2 consists of Tertiary sedimentary rock.
Quaternary glacial and non-glacial deposits are sediments deposited by glaciers and
rivers, respectively, during and between glacial advances of the last 2.5 million years. They
comprise most of the Cedar River valley walls and are exposed extensively within the study
area. The sequence of glacial sediments deposited during the most recent glaciation of
15,000 to 13,000 years ago include Vashon advance outwash (Qva), Vashon Till (QVt), and
Vashon recessional outwash (QVr) sediments. These Vashon glacial sediments constitute
the vast majority of the surficial geology of the plateaus adjacent to the Cedar River valley.
Glacial sedimentary deposits of the pre-Fraser (Qpf) glaciation age include at least two till
layers older than Vashon glaciation. Greater age and the pressures of multiple glaciations
make the pre-Fraser a more consolidated, more erosion-resistant sedimentary unit than
King County River and Floodplain Management 9 April 2015
the most recent glacial sediments. This unit forms near-vertical bluffs along both valley
walls through much of the study area, and resists the rapid erosion that can affect looser
alluvium. Still, the pre-Fraser bluffs adjacent to the river are subject to cliff retreat due to
undermining by the river and to episodic landsliding.
The one outcrop of ice contact (Qvi) deposit found at the downstream end of the south
valley wall, near I-405, may have been deposited as a glacial moraine. This deposit would
be similar to, but contain a higher percentage of silt than, a recessional outwash.
Recent deposits were formed in the Holocene period during the last 13,000 years and are
still being formed by ongoing processes. Recent deposits include colluvium (landslides and
mass wasting material), alluvium (typically valley bottom river sediment) and modified
surfaces (contemporary fill material).
The modern, post-glacial Cedar River has incised through a complex sequence of glacial and
non-glacial deposits, leaving high and steep valley walls along both sides of the river for
much of the length of this study area. Following initial downcutting, the Cedar River has
filled most of its present-day valley with thick deposits of sand and gravel (King County
1993).
With geologically recent incision into glacial and non-glacial sediments, the steep Cedar
River valley walls exhibit widespread and locally severe landsliding. Landslides (Qls) and
mass-wastage colluvial deposits (Qmw) are prevalent along both valley walls, often draped
upon the older pre-Fraser unit. Where in contact with the river, landslides provide
sediment directly to the channel. In this setting, channel migration maintains steep
sideslopes (Booth 1995) as the river erodes and redistributes the colluvial sediment.
The entire Cedar River valley floor is composed of alluvium sediment (typically sand and
gravel) deposited by the river or its tributaries. Younger alluvium (Qyal) is moderately
sorted sediment, largely composed of reworked glacial sediments in this basin. Older
alluvium (Qoal) is texturally equivalent to the younger alluvium but lies at a higher
elevation as a terrace no longer flooded by the river. Such elevated terraces may resist
channel migration more than younger, frequently flooded alluvium. There is a terrace of
older alluvium along the northeast side of the valley adjacent to the river near RM 11.8 to
RM 12.4.
2.3.2 Sediment characteristics
As channel gradient and confinement decrease, so does sediment transport capacity, and
this reduced capacity for the river to transport sediment typically results in sediment
deposition. Accumulations of large wood debris can also force the local deposition of
sediment. Depositional river reaches with unarmored alluvial banks are likely to
experience bank erosion and channel migration, as flow is deflected by deposited material.
The deposited sediment of primary interest in this study includes coarse sand, gravel, and
larger particles. These sediment fractions are often referred to collectively as gravel.
King County River and Floodplain Management 10 April 2015
Perkins et al. (2002) estimated the total gravel supply to the mainstem Cedar River within
this same study area at 11,000 to 12,000 cubic yards per year (cy/yr), most of which comes
from upstream of Landsburg and cliff erosion a few miles downstream of Landsburg. This
annual gravel influx volume is consistent with the 11,000 to 15,000 cy/yr estimated by
King County (1993) and regional sediment yields for basins of this size (Nelson 1977).
Most of the gravel entering Reaches 20 through 18 does not deposit there because of the
steep channel gradient and natural confinement in those reaches. Continuing downstream,
the sediment transport capacity of the Cedar River is adequate to move incoming sediment
through most of the study area (King County 1993; Perkins et al. 2002). Indeed, sediment
transport modeling indicates that sediment transport capacity exceeds sediment supply
between Landsburg and about RM 2, making sediment transport in the Cedar River
sediment-supply limited through most of the study area (King County 1993).
The flat channel gradient in the lower approximately two river miles and backwater from
Lake Washington upstream of the river mouth decrease transport capacity in that area,
resulting in ongoing aggradation. Dredging in this portion of the channel has been
conducted periodically to maintain channel flood capacity; the most recent dredging
activity was in 1998. The average annual sediment deposition volume in the channel from
RM 1.3 to the river mouth between 1998 and 2011 is 9,700 cy/yr (Northwest Hydraulic
Consultants 2011), which is about 70 to 90 percent of the estimated average annual coarse
sediment influx to the entire study area (Perkins et al. 2002). The similarity of the
upstream influx and downstream deposition volumes is consistent with sediment transport
conditions that are sediment-supply limited.
The change in stage elevation through time at U.S. Geological Survey (USGS) gage
12119000 (Cedar River at Renton) reflects ongoing aggradation at RM 1.4 (Figure 4A),
which also is typical of conditions from I-405 to the mouth. A similar plot at USGS gage
12117500 (Cedar River near Landsburg) indicates no long-term aggradation at RM 23.4
(Figure 4B).
King County River and Floodplain Management 11 April 2015
Figure 4. Temporal changes in stage at (A) USGS gage 12119000, Cedar River at Renton, and
(B) USGS gage 12117500, Cedar River near Landsburg (from Gendaszek et al. 2012).
Approximately 200 channel cross sections from Landsburg to I-405 that were surveyed in
2000 or 2003 were resurveyed in 2012 to evaluate change in average riverbed elevations
through the study area. Comparison of the two datasets reveals wide variability in riverbed
elevation changes through the period between surveys (Figure 5). Annual monitoring of
average bed elevation within the City of Renton documents increases in sediment levels
from RM 1.3 (Wells Ave) downstream to the mouth that range from 1 feet to 8 feet (average
is approximately 3 feet) from 1998 to 2011 (Northwest Hydraulic Consultants 2011). In all,
available information suggests a general efficiency in transporting coarse sediment and no
systemic recent changes in in-channel sediment levels from Landsburg to I-405 (RM 1.7).
Monitoring data document ongoing aggradation from RM 1.7 downstream to the mouth.
0
1
2
3
4
1910 1930 1950 1970 1990 2010
Year
Cedar River near Landsburg
Cedar River at Renton
Stream stage (m)Stream stage (m)0
1
2
3
4 A
B
GageReleveled
King County River and Floodplain Management 12 April 2015
Figure 5. Change in average bed elevations, 2000 or 2003 to 2012.
The competence of a river, or its ability to transport a given sediment particle size, typically
decreases with channel gradient in the downstream direction. Figure 6 plots reach-
averaged channel gradient, based on water surface gradient at 1,800 cfs flow (Section 2.4)
with the median surface sediment size through the study area. The riverbed is
predominantly coarse material (e.g., boulder, cobble) in the steep (0.6 percent) channel
gradient of Reaches 20 to 18. From Reach 17 (RM 17.5) downstream to Reach 2 (RM 3),
substrate particle size generally decreases with channel gradient, with some notable local
variability (Figure 6). In parts of the study area there is no apparent trend in substrate size
in the downstream direction, and sampling results can vary widely within a short river
distance because of local morphology and hydraulics (Perkins et al. 2002). The Cedar River
remains a gravel-bedded channel to well downstream of RM 1 even as channel gradient
becomes very flat (<0.2 percent). Finer gravel transitions to mainly sand within 1,000 feet
of the river mouth (Northwest Hydraulic Consultants 2001; U.S. Army Corps of Engineers
1997).
Sediment transport varies as a function of channel gradient, water depth, and riverbed
particle size. Based on these factors, initial movement of riverbed sediment was calculated
to occur at about 2,000 cfs near Landsburg and 2,700 cfs in Renton (Perkins et al. 2003),
both calculations of which are consistent with the empirical observation that significant
sediment movement and deposition begins to occur at about 2,500 cfs in Renton
(Northwest Hydraulic Consultants 2001).
-4.0
-3.0
-2.0
-1.0
0.0
1.0
2.0
3.0
4.0
5.0
6.0
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22Change in average channel elevation, in feetRiver Mile
Change 2003-2012
Change 2000-2012
King County River and Floodplain Management 13 April 2015
Figure 6. Reach-averaged channel gradient and channel substrate particle size (substrate
data from Perkins et al. 2002 and Gendaszek et al. 2012).
2.4 Flood hydrology
Floods along the Cedar River occur primarily during the winter months of November
through February, and each event typically lasts a few days. Annual peak flows at USGS
gage 12117500, the Cedar River near Landsburg, at RM 23.4 are shown in Figure 7 for the
period of record through water year 2011. Peak flows after 2011 are not shown because
2011 is the most recent aerial photo used in Geographic Information System (GIS) analyses
in this study. Selected recurrence interval flood magnitudes from the Cedar River Flood
Insurance Study (Federal Emergency Management Agency 2005) and other flows of
interest are listed in Table 1 and shown in Figure 7 for context. Three floods between 1900
and 1912 equaled or exceeded the current-day annual 1 percent flood of 10,300 cfs at
Landsburg. Masonry Dam and associated waterworks were under construction from 1902
to 1914. Since 1914, only the November 1990 flood has exceeded 10,300 cfs at Landsburg.
King County River and Floodplain Management 14 April 2015
Figure 7. Annual peak flows at USGS gage 12117500 Cedar River near Landsburg.
Table 1. Flow discharge magnitudes, annual percent chance and recurrence intervals.
Discharge at
Cedar River near
Landsburg (cfs)
Discharge at
Cedar River at
Renton (cfs)
Annual
Percent
Chance
Recurrence
Interval
(Years)
King County
Flood Phase or
Example Flood
Source:
Landsburg,
Renton*
1800 2305 Approx. 74 Approx. 1.4 Phase 1 1,4
2800 3510 Approx. 42 Approx. 2.3 Phase 2 1,4
3720 4600 20 5 2,2
4200 5155 Approx. 15 Approx. 6.8 Phase 3 1,4
5000 6080 10 10 Phase 4 1,4
6580 7650 Approx. 4.1 Approx. 24 November 1995 3,3
7870 9390 Approx. 3.3 Approx. 30 January 2009 3,3
8340 9860 2 50 November 1909 2,2
10,300 12,000 1 100 November 1990 2,2
*Source of data in last column of table:
1. King County Flood Warning Phases
2. Federal Emergency Management Agency (2005)
3. USGS flow records
4. Watershed Sciences and Engineering 2013
King County River and Floodplain Management 15 April 2015
The Masonry Dam has a primary purpose of water supply and power generation, so its
flood control benefits are only opportunistic. However, the presence of this dam appears to
have decreased flood peaks since 1914, as suggested by the four large flood events in the
dozen years prior to 1914 and only one event of similar magnitude in the century since
1914 (Figure 7). The post-dam 2-year, 10-year, and 100-year recurrence intervals have
been reduced by 47, 54, and 56 percent, respectively, relative to pre-dam conditions
(Gendaszek et al. 2012). Water diversion or withdrawal for water supply and power
generation may alter lower flows, but have little impact on flood peaks.
With a decrease in peak flows since 1914 and widespread increases in channel
confinement due to bank armoring since the 1960s, less frequent and larger discharges
remain within the riverbanks through much of the study area. A comparison of inundated
width to bankfull channel width1, averaged by reach for various flows, gives an indication
of channel confinement (Figure 8; this is the “flood confinement ratio” of Perkins et al.
2002). A ratio of 1 indicates that the flow is entirely contained in the channel. The 5,000 cfs
flow (annual 10 percent flood) is entirely contained in several reaches, and in some reaches
a discharge of 10,300 cfs (annual 1 percent flood) is contained (Figure 8).
A decrease in the peak magnitude of large floods by necessity results in longer durations of
moderate and lower flows than would occur in unaltered conditions, because the total
volume of water that flows into the reservoir in a given flood event is unchanged but that
water volume is released more slowly by the dam. Much of the longer-duration flows likely
exceed the threshold at which sediment movement begins (approx. 2,000 cfs near
Landsburg).
1 Bankfull width was represented by the distance between bank stations identified at every cross section in
the Cedar River HEC-RAS hydraulic model (WSE 2013). Bank stations in HEC-RAS mark the transition in
hydraulic conditions from the channel to overbank areas and typically are located at or near the top of bank.
Visual inspection of bank station locations at each cross section in the HEC-RAS hydraulic model indicated
that this was an acceptably accurate representation of the bankfull location. Inundated width, provided
directly by the HEC-RAS model at each cross section, includes the full width of the channel and floodplain that
is equal to or lower than the water surface elevation of interest, and as such, may overstate the width of
floodplain that is inundated by continuous overbank flow.
King County River and Floodplain Management 16 April 2015
Figure 8. Cedar River flood confinement ratio, by reach, at various flow events.
2.5 Large wood
The presence of large wood has the potential to increase water surface elevations through
vertical changes in the elevation of the river bed resulting from sediment deposition
upstream of large wood accumulations. The increase in water surface elevation caused by
large wood can increase the frequency and extent that flood flows access adjacent
floodplain areas, and consequently have an influence on the likelihood of avulsion and
channel migration (Brummer et al. 2006). The presence of large wood accumulations is
relevant to mapping Cedar River channel migration by avulsion because this study
evaluates the frequency and depth of inundation in low lying areas as a criterion for
mapping avulsion hazards under current conditions. The management of riparian forests to
allow more and larger trees means that the volume of large wood in rivers is likely to
increase through the 100-year timeframe relevant to CMZ mapping. See also Section 4.4
for more discussion of the effect of large wood on channel migration.
A study in progress by King County at the time of writing is evaluating the presence and
distribution of large wood in the Cedar River (K. Akyuz, pers. comm. 2014). Preliminary
data from the study indicate that there were an estimated 11,500 total pieces of large wood
on the Cedar River in 2010, and the vast majority of the pieces of wood were categorized as
small logs and branches. There were 145 key pieces (wood pieces large enough to act as
key member in the formation of a log jam) at an average of 6.5 per river mile. Higher
densities of total wood counted and key pieces occurred in unconfined reaches than in
0
1
2
3
4
5
6
7
8
9
10
11
12
1 2 3 4 5 6 7 8 9 1011121314151617181920Flood confinement ratio (Inundated width / bankfull width) Reach
1800 cfs 2800 cfs 5000 cfs 6580 cfs 10300 cfs
King County River and Floodplain Management 17 April 2015
confined reaches. These values for large wood metrics on the Cedar River are low relative
to large wood in natural conditions on other Pacific Northwest river channels (Fox and
Bolton 2007). The potential effect of large wood accumulations on channel migration is
discussed in Section 4.4.
King County River and Floodplain Management 18 April 2015
3.0 METHODS
Channel migration on the Cedar River was evaluated and mapped using information from
existing studies, field observations, and analyses conducted in GIS Esri ArcMap 10.0.
Information from several existing studies of the geology, geomorphology, hydrology,
hydraulics, land use, and other factors relevant to Cedar River channel migration forms the
foundation of this study. These studies include Cedar River Current and Future Conditions
Report (King County 1993), Geologic map of Maple Valley (Booth 1995), Cedar River gravel
study (Perkins et al. 2002), Cedar River Flood Insurance Study (Federal Emergency
Management Agency 2005) and associated hydraulic model (Harper, Houf, Righellis 2002),
historical river channel data for the Cedar River (Collins et al. 2003), and an article titled
“Geomorphic response to flow regulation and channel and floodplain alterations in the
gravel-bedded Cedar River, Washington, USA” by Gendaszek et al. (2012).
The river channel and other parts of the study area were accessed by raft or on foot. Field
observations were made of river bed and bank materials, evidence of erosion, location and
condition of bank armoring, general channel pattern, and the presence and nature of
hydraulic or geomorphic controls. Channel substrate data were not collected because they
are available from Perkins et al. (2002) and Gendaszek et al. (2012).
Historical and current channel locations were documented in GIS from historical
information described in Section 3.1. Lateral channel migration rates and the potential for
abrupt channel shifting by avulsion were evaluated in GIS, as described in Section 4.3. In
Section 5.2, calculated channel migration rates and mapped avulsion potential were used in
combination with information from field observations and other relevant resources, such
as hydraulic models, geologic maps, and other geomorphic studies, to map channel
migration hazards throughout the study area.
3.1 Historical and current information used in report
Historical channel locations were digitized in GIS at a scale of 1:1,000 by Collins et al.
(2003) from orthorectified aerial photos dated 1936 through 2000 (Table 2). The
digitization process included mapping the active channel for each photo year as the
composite of low flow channel, bare gravel bars, and vegetated patches on alluvial surfaces
(Collins et al. 2003; O’Connor et al. 2003). King County digitized historical channel
locations for 2005 and 2011 using the same methods as Collins et al. (2003).
The horizontal accuracy of the digitized historical channel locations is estimated to be
within 25 to 40 feet of actual location (Collins et al. 2003). There are two main sources of
inaccuracy: the orthorectification process and the digitization process. Channel locations
digitized from 1944 and 1985 were not used in this analysis because of inaccuracies
King County River and Floodplain Management 19 April 2015
exceeding 60 feet. The high level of inaccuracy in 1944 and 1985 resulted mainly from poor
image quality in those two years.
Digital aerial photos and LiDAR coverage from 2013 also are available for the study area.
Because there were relatively minor flood events and negligible channel changes between
2011 and 2013, the 2013 channel was not digitized and the 2011 channel is taken to
represent present-day conditions for this analysis. LiDAR imagery from 2011 was
consulted for this study.
Table 2. Aerial orthophotos used or consulted in this report.
Year Scale Estimated Horizontal
Accuracy† Source
1936 1:10,500 10.3 meters (33.8 ft) King County
1948 1:21,000 16.3 meters (53.5 ft) King County Conservation District/USDA-NRCS
1959 1: 7,800 5.9‡ meters (19.4 ft) King County
1964 1:21,000 9.0 meters (29.5 ft) King County Conservation District/USDA-NRCS
1970 1:12,000 5.0 meters (16.4 ft) King County
1980 1:58,000 10.0 meters (32.8 ft) University of Washington Libraries
1989 1:13,500 7.2 meters (23.6 ft) King County
1995 1:12,000 6.0 meters (19.7 ft) University of Washington Libraries
2000 2 ft pixel 4.0 meters (13.1 ft) King County
2005 1 ft pixel 2.0 meters (6.6 ft) King County
2011 1:1,200 0.3 meters (1.0 ft) King County
2013 0.5 ft pixel 0.1 meters (0.3 ft) King County
† National Standard for Spatial Data Accuracy (NSSDA) 95% statistic indicates the horizontal distance over
which the user can be confident that the horizontal position of a feature on the image will be within its true
location 95% of the time (Collins et al. 2003).
‡ Photo set does not encompass entire study area and contained 10 of 20 field-verifiable locations that the
NSSDA 95% statistic requires. Of those 10, horizontal accuracy is 5.9 m (Collins et al. 2003).
A circa 1920 USGS topographic map also was consulted but not used quantitatively due to
its small scale (1:125,000).
Historical plat maps surveyed by the General Land Office (GLO) between 1865 and 1880
were reviewed but were not included quantitatively in this analysis because of inherent
inaccuracies, as described by Collins et al. (2003). Further, operation of Masonry Dam and
associated waterworks since 1914 (described in Section 2.4) has reduced the size of major
flood flows; these reduced flows have resulted in long-term alteration of channel
conditions throughout the Cedar River (Perkins 1994). With such systemic changes after
1914, the channel locations and conditions shown in the circa 1865 GLO maps are not
directly applicable to an analysis of present-day channel migration hazard.
King County River and Floodplain Management 20 April 2015
3.2 Channel Migration Zone Components
Channel migration hazards in the Cedar River were mapped by identifying the component
parts of a CMZ, as specified by King County (2014) and consistent with Ecology (1994-
2014). CMZ components are described in the equation below and illustrated schematically
in Figure 9.
CMZ = HMZ + AHZ + EHA – DMA
where
HMZ = Historical Migration Zone
AHZ = Avulsion Hazard Zone
EHA = Erosion Hazard Area. = Erosion Setback (ES) + Geotechnical Setback (GS)
DMA = Disconnected Migration Area
Figure 9. Plan view schematic of Channel Migration Zone (CMZ) components. Modified from
Rapp and Abbe (2003).
Each CMZ component is defined and its mapping methods are described in Section 3.3.
3.3 Mapping criteria and methods
This section defines each CMZ component and hazard area and describes mapping criteria
and methods. As described in Section 3.2, the combination of the following components
constitutes the CMZ: CMZ = HMZ + AHZ + EHA – DMA.
King County River and Floodplain Management 21 April 2015
Once the CMZ was delineated, severe and moderate hazard areas were identified within it so as
to recognize that channel migration hazard is not equal throughout the CMZ. In general,
any part of the CMZ that is not mapped as a severe hazard area is mapped as a moderate
hazard area. The criteria by which parts of the CMZ components are mapped as a severe or
moderate hazard area are included with the description of each CMZ component.
3.3.1 Historical Migration Zone
The Historical Migration Zone (HMZ) is the portion of a CMZ study area that the channel
has occupied during the historical record (King County 2014). The HMZ is mapped as a
composite footprint of historical active channel locations from 1936 to 2011, as listed in
Table 2. The HMZ typically is a fundamental component of the CMZ.
The entire HMZ was mapped as severe hazard area.
3.3.2 Avulsion Hazard Zone
The Avulsion Hazard Zone (AHZ) is the area outside of the HMZ that is subject to avulsion
hazard (King County 2014). To map the AHZ, low-lying areas were identified from the 5,000
cfs (annual 10 percent flood) inundation map. Low-lying areas inundated by 5,000 cfs that
occupy a shorter distance in the down-valley direction than the adjacent mainstem channel were
evaluated in the field. Other pertinent information was considered in evaluating avulsion hazard,
such as whether there was a history of avulsions in the immediate area or if there were
discernable trends in the accumulation of wood or sediment in the main channel near the
potential avulsion site.
Potential avulsion pathways were included in the AHZ if they met all four of the following
criteria (King County 2014):
1. Low-lying ground or channel that is equal to or lower than the water surface elevation of
frequent flooding in the current main channel.
2. The length of the potential avulsion pathway follows a shorter distance (and steeper
gradient) than the main channel.
3. The substrate in the banks and bed or floodplain of the potential avulsion pathway is
erodible material.
4. The potential avulsion pathway is a likely avulsion route based on consideration of
Quaternary history, avulsion history in the basin, flow regulation, channel alteration,
sediment trends, and large woody debris loading.
King County River and Floodplain Management 22 April 2015
An Avulsion Hazard Zone was mapped as a severe hazard area if it met any of the following
criteria:
1. Potential avulsion pathways have little or no vegetation, or show evidence of fresh
scour, channel widening or oversteepening, consistent with erosion from recent flood
events, or
2. Potential avulsion pathways have a direct low-elevation surface connection to the
main channel such that it is flooded deeply and frequently (which may be indicated
by surface flow through the pathway even during periods of low river flow), or
3. Indicators of avulsion hazard regarding accumulation of sediment or large wood in
the main channel, or changes to main channel meander geometry, exist in close
proximity to a potential avulsion pathway.
Severe AHZs were mapped as wide as the 2011 average Active Channel of the reach in
which the avulsion pathway is located. The AHZ typically was centered along the centerline
of avulsion pathway unless site-specific conditions such as variability of substrate indicated
it was appropriate to map the AHZ otherwise.
An AHZ that did not meet any of the three criteria listed above for the severe hazard AHZ
was mapped as a moderate hazard AHZ. As with a severe AHZ, a moderate AHZ was
mapped to a width equal to the average Active Channel width of the present river channel
reach in which the avulsion pathway is located and along the centerline of the avulsion
pathway unless conditions indicated otherwise.
Where an artificial structure such as a levee blocks a potential avulsion pathway that
otherwise meets the criteria to be mapped as an AHZ except for the blockage, that pathway
was mapped as an AHZ if the top elevation of the blocking structure is lower than the water
surface elevation of the 1 percent annual chance flood and the blocking structure is not
likely to restrain channel migration. The AHZ behind the blockage was mapped as a severe
hazard area if the severe hazard mapping criteria, listed above, were met, or it was mapped
as a moderate hazard area if the criteria were not met.
3.3.3 Erosion Hazard Area/Erosion Setback
The Erosion Setback is that part of the EHA within the CMZ that is susceptible to lateral
channel migration due to stream or river erosion (King County 2014). The width of the
Erosion Setback (referred to as EHA/ES) was calculated as a lateral channel migration rate
times a given time period.
To calculate lateral channel migration rates, channel centerlines were digitized along the
mid-line of the active channel in each year of aerial photos and lateral channel migration
distances were measured between channel centerlines in sequential aerial photos (Table
2). These distances between channel centerlines were measured along transects spaced
400 feet apart, down-valley, and oriented perpendicular to the centerline of the Historical
Migration Zone.
King County River and Floodplain Management 23 April 2015
Average annual lateral channel migration rates were calculated as the lateral migration
distance measured between sequential aerial photos divided by the time elapsed between
the photos. The rate used in this study is the time-weighted average of the absolute value of
the migration distance measurements described above. Using the absolute value calculates
channel migration as if it occurred in one direction between every pair of photos.
Channel migration was measured at sites where channel migration occurred as channel
expansion. The channel expansion distance was calculated as the difference in active
channel widths as measured at HMZ transects in sequential aerial photos. That distance
was divided by 2 to indicate the extent of expansion that had occurred on each side of the
active channel in the first photo. The resulting distance was divided by the number of years
between aerial photos to calculate the migration rate at that location.
Channel migration rates were calculated for each reach using aerial photos from between
1964 and 2011 and for Reach 1 through Reach 11 using aerial photos from between 1936
and 2011 (Table 2). Migration rates between 1936 and 1964 could not be calculated
upstream of Reach 11 either because of a lack of photo coverage or the inferior accuracy of
existing photos. Collins et al. (2003) describe lesser accuracy of photo orthorectification in
these earlier photos resulting from fewer observable landmarks in the eastern portions of
the study area.
Channel migration rates were calculated in two ways: first, rates were calculated using all
measurements taken, and second, rates were calculated using only those measurements
where erosion occurred. For erosion to have occurred, not only must there be a movement
of the channel centerline at an HMZ transect, but the channel edge in a given photo-year
must have moved outside the channel edge of the previous photo-year. This measurement
method captured lateral channel migration and channel expansion but excluded channel
contraction and locations of no erosion. If the channel remained entirely within the
boundaries of the channel from the previous aerial photo, no erosion was assumed to have
occurred even if the channel centerline had moved.
3.3.3.1 Erosion Hazard Area/Erosion Setback applied to the Historical
Migration Zone or to the Active Channel
The width of the Erosion Setback was calculated using the eroding-only channel migration
rates. For each reach, the width of the EHA/ES for lateral migration in Holocene valley-
bottom alluvium was calculated as the greater of the following two distances (Figure 10).
1. 50 years of lateral migration times the channel migration rate, applied to each side of the
HMZ, or
2. 100 years of lateral migration times the channel migration rate, applied to each side of the
most recent active channel (2011).
King County River and Floodplain Management 24 April 2015
Figure 10. Plan view schematic of the Erosion Hazard Area/Erosion Setback.
The EHA/ES can be further broken down into moderate and severe hazard areas. The width of
the severe hazard area within the Erosion Setback was delineated as the greater of the
following two distances.
1. 25 years times the representative channel migration rate of this reach applied to each side
of the HMZ, or
2. 50 years times the representative channel migration rate of this reach applied to each side
of the most recent active channel (2011).
The area that lies between the severe channel migration hazard area and the outer edge of
the Erosion Setback was mapped as moderate hazard area.
Where historical channel locations indicated that there was a measureable, consistent
down-valley component to lateral channel migration, the EHA/ES was adjusted based on
down-valley migration rates measured at the affected sites.
Erosion-resistant landforms that the EHA/ES intersected included tall bluffs composed of
the Pre-Frasier glacial formation and Vashon-age glacial drift at several locations in the
study area (Map 2, Appendix A). In these locations, the width of the portion of the EHA/ES
within the more-resistant landform was calculated using an appropriately lower channel
migration rate. The lower channel migration rate was based on lateral retreat rates
observed in the same or similar tall bluffs that the active channel encountered and during
that part of the historical record of the study during which the active channel eroded that
King County River and Floodplain Management 25 April 2015
landform. The resulting EHA/ES width is likely to be narrower than it would be in Holocene
alluvium in the same river reach (Figure 11).
Figure 11. Cross-section schematic of Erosion Hazard Area/Geotechnical Setback.
3.3.3.2 Erosion Hazard Area/Erosion Setback applied to Avulsion
Hazard Zone
Once an avulsion occurs, lateral migration is assumed to proceed from the new channel
location. The width of that lateral migration is calculated as an EHA/ES added to the AHZ.
An EHA/ES applied to either a severe AHZ or moderate AHZ was mapped as a moderate
hazard area. The widths of this EHA/ES applied to an AHZ may vary as follows:
1. Erosion Hazard Area/Erosion Setback applied to a severe AHZ: This Erosion Setback
distance was added to each side of a severe AHZ to a width equal to a range of 25 years
to 50 years times the representative channel migration rate for that study reach. The
number of years is based on the extent to which AHZ mapping criteria in Section 3.3.2
were met.
2. Erosion Hazard Area/Erosion Setback applied to a moderate AHZ: This Erosion Setback
distance was added to each side of a moderate AHZ to a width equal to 25 years times the
representative channel migration rate for that the study reach.
3.3.4 Erosion Hazard Area/Geotechnical Setback
Where the outer edge of the EHA/ES encountered an erodible land surface that is greater
than 20 feet in height above Ordinary High Water, a Geotechnical Setback, referred to as
EHA/GS, was applied to the outer edge of the EHA/ES (King County 2014). The EHA/GS
was delineated at a 1H:1V slope measured from the predicted toe of slope after applying
the EHA/ES (Figure 11). No EHA/GS or EHA/ES was applied to sound bedrock showing no
signs of erosion.
The entire EHA/GS was mapped as moderate hazard.
King County River and Floodplain Management 26 April 2015
3.3.5 Disconnected Migration Area
A Disconnected Migration Area (DMA) is the area located landward of an artificial structure
that is likely to restrain channel migration and that meets criteria in Washington
Administrative Code 173-26-221(3)(b) and King County (2014). In other words, the DMA is
an area that would be subject to channel migration were it not for the presence of the
artificial structure.
Areas landward of the legally existing, publicly maintained artificial structures (e.g.,
revetments, levees) that met the following criteria were mapped as a DMA:
1. Within incorporated areas and urban growth areas, an artificial structure that limits
channel migration.
2. In all areas, an artificial structure that is likely to restrain channel migration and is built
above the one hundred-year (100-year) flood elevation.
3. State highways and sole-access major county roads.
4. Legally existing active railroads.
An artificial structure was considered likely to restrain channel migration if its
construction, condition, and configuration are consistent with current relevant design and
construction standards and if the present channel is unlikely to migrate landward of the
structure (King County 2014). Levees and revetments maintained by King County within
unincorporated King County were evaluated for their likelihood to restrain channel
migration. Information on construction date and methods, damage, and repair history was
consulted from King County files. Available project repair design plans were reviewed
regarding construction standards. Levees and revetments maintained by King County or
the City of Renton within the City of Renton were evaluated as to the structure’s ability to
limit channel migration.
Whether an artificial structure was built above the elevation of the 10,300 cfs discharge
(annual 1 percent flood2) was determined from the hydraulic model prepared for the Cedar
River flood study (Harper, Houf, Righellis, Inc. 2002) and inundation maps based on the
flood study hydraulic model (Watershed Science and Engineering 2013). Relevant
empirical evidence also was considered regarding structure elevations relative to the water
surface elevation of the 10,300 cfs discharge.
If an artificial structure did not meet all criteria necessary to map a DMA, then the severe
and moderate hazard area delineations were not revised. This approach was taken so as
recognize the channel migration hazard landward of that structure.
2 Referred to as the 100-year flood in relevant WAC and KCC sections cited above.
King County River and Floodplain Management 27 April 2015
4.0 CHARACTERISTICS OF CHANNEL
MIGRATION IN THE STUDY AREA
4.1 Channel migration processes
Channel migration occurs by three processes in the Cedar River study area: lateral
migration, channel expansion, and avulsion. Lateral channel migration occurs as a
combination of bank erosion along one riverbank coupled with sediment deposition along
the opposite bank. The result is a progressive net movement, or migration, of the channel
across the valley bottom. A comparison of the 1964 and 2011 channel locations near RM
15.5 on the Cedar River illustrates lateral migration (Figure 12). There also may be a down-
valley component to the lateral migration. Through time, the down-valley component
would result in an area downstream and between river meanders being affected by
channel migration, not just an area laterally landward from the channel. Lateral migration
is the main type of channel migration affecting the Cedar River in the study area.
Figure 12. Example of lateral migation on the Cedar River near RM 15.5.
Channel expansion is a widening of the channel, which manifests as an increase of the
channel width toward both riverbanks. Conditions that cause this type of channel
migration include an increase in sediment influx or the eroding effects of a large flood flow.
Channel expansion also can result from channel incision if the lowering of the riverbed
King County River and Floodplain Management 28 April 2015
undercuts and destabilizes the riverbanks (Simon 1989). Channel expansion on the Cedar
River occurred near RM 5 after a 2001 landslide from the right (north) bank deposited a
large volume of sediment directly in the river channel (Figure 13).
Figure 13. Example of channel expansion on the Cedar River at RM 5.
In a channel migration process called an avulsion, the channel shifts abruptly to a different
location without laterally eroding through the land between the two channel locations. The
channel may shift by avulsion rapidly, such as during a single flood event. Avulsions also
may occur more gradually, as the majority of flow shifts from one channel to another.
Avulsions may be triggered by the onset of unpredictable conditions such as a landside or
log jam. Though avulsion triggers may be unpredictable, certain conditions favor the
occurrence of avulsions, as described in Section 3.3.2. Avulsions have occurred in the Cedar
River, for example, near RM 10.5 where the split flow conditions in 1989 shifted to a single
channel in 1995 without eroding the forested island between channel locations (Figure 14).
Conditions that favor avulsion (Section 3.3.2) exist within the study area.
King County River and Floodplain Management 29 April 2015
Figure 14. Example of avulsion on the Cedar River near RM 10.5.
Comparison of channel locations evident in historical maps and aerial photos reveals the
location, type, and extent of past channel migration. Information about past channel
migration is used to predict future channel migration and map channel migration hazard
areas. Comparison of channel locations in sequential aerial photos in a GIS format informs
the evaluation of lateral channel migration, channel expansion and avulsion, as does the
compilation of all digitized historical channel locations. The composite map of historic
channel locations becomes the HMZ shown in Map 3, Appendix A.
Water surface elevations of selected flows in the mainstem channel were compared to the
topographic elevations of adjacent valley-bottom surfaces and secondary channels using
existing Cedar River hydraulic model results (Harper, Houf, Righellis, Inc. 2002 and
Watershed Sciences and Engineering 2013) and LiDAR digital surfaces. The elevation
difference between the water surface at 5,000 cfs (annual 10 percent chance flood) and the
valley-bottom surface topography is shown in Map 4, Appendix A. Map 4 is equivalent to a
“Height Above Water Surface” map produced by Jones (2006) except that Map 4 shows
color only in the areas of the valley bottom that are below the 5,000 cfs water surface
elevation, not above it. A 5,000 cfs flood is equivalent to a Phase 4 event in King County
flood warning phase system (Table 1). The 5,000 cfs flood event was selected for Map 4
King County River and Floodplain Management 30 April 2015
because it is a relatively frequent flood that may access low-lying areas of the valley bottom
and so is relevant to mapping avulsion hazard. Map 4 is not an inundation map because it
does include consideration of the hydraulic connectivity of the colored valley-bottom areas
to the main channel at a discharge of 5,000 cfs.
Dark blue in Map 4 indicates valley-bottom areas that are as much as 5 feet lower in
elevation than the water surface at 5,000 cfs and yellow to green indicates valley-bottom
areas that are as much as 1 foot lower in elevation than the water surface at 5,000 cfs.
Along the river channel, this map illustrates the difference in elevation between the water
surface at 5,000 cfs and the water surface at the time that LiDAR was flown. Therefore, the
water depth within the channel is illustrated generally in Map 4 and does not represent
specific localized conditions in the channel.
4.2 Morphology of the study reaches
A river reach is a length of channel that exhibits consistent physical conditions. River
reaches in the study area were identified based primarily on channel gradient, channel
confinement, channel pattern, and riverbank material. Channel sinuosity (ratio of channel
length to valley length), confluence with tributaries, and the presence of infrastructure
were considered secondarily.
Twenty reaches were identified, numbered in upstream direction through the study area;
many of the reaches correspond closely to the river segments used by Perkins et al. (2002).
Reach characteristics are summarized in Table 3 and described below in the downstream
direction.
The State Department of Ecology defines channel confinement based on the ratio of active
channel width to valley bottom width. A ratio of less than 2 is confined; a ratio of greater
than 4 is unconfined; and a ratio between 2 and 4 is moderately confined (Ecology 1994-
2014). The only place where the ratio is less than 4 on the Cedar River in this study area is
at Landsburg Bridge and a few hundred feet downstream. In this report, the term
confinement does not refer to the active channel/valley bottom ratio defined by Ecology,
but is used to generally describe the relative level of constraint placed on the channel by
the proximity of the valley walls, terraces, or constructed features.
Channel patterns are described in the study reach as two types. A single-channel pattern, or
single channel, conveys flow up to and including bankfull flow entirely in one main channel.
A multi-channel pattern, or multiple-channel pattern, consists of more than one channel
separated by islands that may be stable and vegetated. An anabranching channel (see
footnote 3) is an example of multi-channel pattern.
Reaches 20 through 18 are among the steepest in the study area, with channel gradients
ranging from 0.67 to 0.55 percent. The single channel in these reaches generally is confined
and often in contact with high banks or bluffs. Channel substrate is a coarse gravel/cobble/
King County River and Floodplain Management 31 April 2015
boulder mix. With most gravel influx being routed through these reaches (Section 3.2.3),
gravel bars are infrequent and narrow.
The river in Reach 17 is single channel with a 0.62 percent gradient and increasing channel
width in the downstream direction. This reach has erosion-resistant banks at its upstream
end and a right bank composed of colluvium along its downstream end. Coarse channel
substrate, some of which appears to have come from a right bank landslide, is evident in
the mid-channel bar just upstream of the CRT Bridge at the downstream end of Reach 17
(RM 17.6).
Reaches 16 and 15 have a single channel, a widening floodplain and decreasing channel
gradient (ranging from 42 to 60 percent). Bank materials alternate between continuous
lengths of armoring and unarmored alluvium. Bare gravel bars suggest increased in-
channel sediment deposition. Side channels or floodplain channels are present across the
interior of every meander bend in Reach 15.
The river in Reaches 14 and 13, between the SR 18 (RM15.3) and SR 169 (RM 14.1)
bridges, is a single, relatively straight channel. Alluvial banks are armored in much of Reach
14 or confined by bridge abutments. The channel in Reach 13 runs contiguous to an
erosion-resistant bluff and the alluvial fan of Peterson Creek along its left (west) bank. In
March 2014, a relatively small landslide from the left bank bluff briefly blocked the
mainstem channel in the Royal Arch neighborhood area at approximate RM 14.5, but the
channel quickly incised through the landslide debris and remained in the same location.
In Reach 12, the single channel is bounded by SR169 and CRT bridge abutments at its
upstream end and bank armoring at every outside bend as well as some interior bends.
Landward and between bank armoring segments, floodplain channels show bare gravel or
surface water, or both, evidence of frequent flow. Taylor Creek and associated floodplain
channels flow and coalesce behind the Getchman levee before joining the river just
upstream of Jan Road levee (RM 13.4). Unarmored alluvial river banks exhibit active
erosion along both left and right banks between revetments. The channel gradient in Reach
12 is 0.43 percent.
In Reach 11, the single channel is in contact with a right bank terrace and glacial bluffs
through the entire reach. Ongoing bank erosion and channel migration into the terrace of
old alluvium is evident in a very tight curve at the Rawson bend (RM 12.5). The channel
flows along the right bank base of tall glacial bluffs from RM 12.1 to RM 11.8 (across from
the Lions Club area).
In Reach 10, the single channel flows under Cedar Grove Bridge near its upstream end,
curves along the Rainbow Bend levee removal site, and then flows in a straight line
adjacent to the CRT for almost 2,000 feet. Even with the Rainbow Bend levee removal, the
channel has armoring or abutments on at least one of its banks through almost 90 percent
of this reach. The levee removal project excavated two floodplain channels that are readily
accessed by flow from the main channel.
King County River and Floodplain Management 32 April 2015
Table 3. Cedar River reach characteristics.
Reach
River Mile€
Length
(miles)
Average
Gradient
(%)†
Armored
Length
(%)‡
Channel pattern, river banks, geology,
constraints**
General location - infrastructure, King
County facilities, tributaries, etc. D/S* end U/S* end
1 0 1.633 1.6 0.18 100 Single channel, nearly straight, flat gradient. Leveed channel within City of Renton
2 1.633 3.241 1.6 0.27 9
Single incised and confined channel, mild
meanders. Narrow valley. Along SR 169 U/S of I-405
3 3.241 4.57 1.3 0.35 47
Single channel, one meander; 1980s landslide
on LB; armored spots on alluvial banks. Maplewood subdivision on RB
4 4.57 5.135 0.6 0.43 53 Multiple channels; 2001 RB landslide. Ron Regis Park area
5 5.135 6.435 1.3 0.34 60
Single channel, flatter gradient, mild
meanders; armored spots on alluvial banks.
Elliott Bridge and lower Jones Road
area
6 6.435 7.695 1.3 0.46 78
D/S part has single channel, mostly armored
banks. U/S is multi-channel, unconfined. Riverbend and Cedar Rapids area
7 7.695 9.39 1.7 0.44 64
Single channel, large meander; moderately
confined by relatively high alluvial RB. Upper Jones Road area
8 9.39 10.35 1.0 0.30 43 Single channel; narrow valley; bedrock walls. Bedrock area
9 10.35 10.97 0.6 0.38 40 Multiple accessible channels. Valley narrows. Belmondo area
10 10.97 11.69 0.7 0.36 81
Single channel; mostly armored alluvial bank,
until 2013.
Cedar Grove; RB Rainbow Bend levee
removed 2013
11 11.69 12.666 1.0 0.39 15 Single channel; RB old alluvium terrace, bluff. Rawson curve to Lions Club area
12 12.666 14.05 1.4 0.43 69
Single channel; armored alluvial bends; side
channels or creek landward of armoring.
Getchman, Rhode, Rutledge-Johnson
Jan Rd facilities; Taylor Creek joins RB
13 14.05 14.757 0.7 0.46 30
Single channel; mild meander; tall LB bluffs,
the site of 2014 landslide. Royal Arch area
14 14.757 15.52 0.8 0.53 37
Relatively straight single channel; alluvial
banks w/armor. SR 169 and SR 18 Bridges
15 15.52 16.55 1.0 0.60 58
Single channel with accessible side channels;
armored spots on alluvial banks.
Doris Creek, Dorre Don Road; Lower
Don area
16 16.55 17.64 1.1 0.42 67
Single channel; armored lengths of alluvial
banks; erosion resistant bends.
Upper Dorre Don area to Orchard
Grove
17 17.64 18.37 0.7 0.62 0
Single channel; one meander along colluvial
material on RB.
Isolated residential areas on both
banks, upstream of Cedar River Trail
18 18.37 19.654 1.3 0.67 19
Single channel in tortuous bends; tall bluffs
both banks are sediment sources. Arcadia-Nobel area
19 19.654 21.02 1.4 0.55 13
Single channel; relatively straight; tall bluffs
are sediment source.
Isolated residential areas on both
banks
20 21.02 22.063 1.0 0.66 18 Steep single channel; glacial material banks. Landsburg Bridge at U/S end of study
King County River and Floodplain Management 33 April 2015
Table 3 footnotes:
€ River Miles with 3 decimal places are located at cross sections surveyed for the Cedar River Flood
Insurance Study (FEMA 2005) and hydraulic model (Harper, Houf, Righellis (2002). River Miles with 2
decimal places are located between surveyed cross sections.
* D/S = downstream; U/S= upstream.
† Average gradient measured from the water surface elevation at the 1,800 cfs flow.
‡ Armored length is the channel length armored by King County or Renton flood protection facilities on
either one or both banks. Total cannot exceed 100%.
** LB= left bank and RB = right bank when viewed downstream.
The river in Reach 9 is a single channel with a valley bottom that narrows in downstream
direction. The channel has shifted by avulsion and also eroded the alluvial floodplain by
lateral migration. Channel migration is active in Reach 9. The downstream end of Reach 9
and upstream part of Reach 8 are referred to as the Belmondo area.
The river in the upstream part of Reach 8 has a multi-channel pattern, with a left bank side
channel that is actively connected to the mainstem throughout the year. Mid-channel
gravel bars downstream of a circa 2009, relatively small right bank landslide split the
mainstem channel into multiple flow paths. The valley bottom continues to narrow going
downstream through Reach 8, with bedrock walls on outside bends. The downstream end
of Reach 8 is at upper Jones Road Bridge.
In Reach 7, the floodplain broadens as the channel exits the area of bedrock walls. The
single channel remains moderately confined as it flows through the largest amplitude
meander bend of the study area and is bounded by a high right bank alluvial surface. More
than half of the downstream part of this reach has armored banks. The unarmored alluvial
banks show active erosion.
In the upstream 1,200 feet of Reach 6, the river has a multi-channel pattern that is wide
and unconfined, with active bare gravel bars and recently shifting channel locations along
the Cedar Rapids levee setback project. This part of Reach 6 exhibited dynamic channel
migration from 2009 to 2011. Through almost all of the remainder of Reach 6, the river
flows in a single channel and is armored on one or both banks.
The river in Reach 5 flows in a single channel through more than a mile of low-amplitude
meanders that are armored on most outside bends. Alluvial banks show erosion between
armored bends. Channel gradient decreases to 0.34 percent.
Reach 4 is the site of a 2001 landslide from the right bank that blocked the main channel
and induced its rerouting. Similar slide activity and channel responses are evident in
historical aerial photos. Episodic infusion of sediment over several decades causes this
reach to have a multi-channel pattern and an average active channel width about four
times that along most other parts of the river. Although most of the 2001 slide material
appears to have been evacuated by channel erosion, channel expansion has occurred since
2001 and adjustments are ongoing in this unconfined reach.
King County River and Floodplain Management 34 April 2015
In Reach 3, the river flows in a single channel under SR 169/CRT bridges and around one
relatively large-amplitude meander bend. Left bank substrate is composed of
discontinuous bank armoring, colluvial material (at the site of a 1980s landslide), and a
short stretch of bedrock. Between the non-alluvial left bank substrate and a right bank
subdivision, the channel is confined and relatively narrow in this reach. The channel begins
to exhibit incised conditions in the downstream 1,000 feet of Reach 3.
Through Reach 2, the river flows in a single channel through low-amplitude meanders as
gradient drops to less than 0.3 percent. The narrowing valley bottom and SR 169 confine
the channel in place. The channel is incised through Reach 2.
The Cedar River in Reach 1 flows under I-405 at RM 1.63 and between continuous levees
on both river banks through the center of Renton to the mouth. Channel gradient is less
than 0.2 percent. Channel substrate is gravel through most of this reach and transitions to
sand near the river mouth.
Sinuosity, S, was calculated as the ratio of active channel centerline length to valley bottom
centerline length, for each reach in each photo-year from 1936 to 2011 (Figure 15).
Channels are considered sinuous with S values less than 1.5 and meandering with S values
greater than 1.5 (Leopold et al. 1964). A sinuosity of 1.0 indicates a straight channel, and
examples of straight-channel sinuosity are the channelized Reach 1 within the City of
Renton and the very straight Reach 20. The largest S values are for Reaches 3, 12 and 17,
which all approach or equal the meandering category (S=1.5). These larger S values result
from one or a few meander wavelengths occupying a relatively short valley distance. The
majority of study reaches are in the sinuous category and their sinuosity has not varied
greatly through time. Increases in the calculated sinuosity in some reaches may result from
a narrowing of the active channel with an associated minor increase in active channel
centerline length.
Figure 15. Channel sinuosity by reach.
0.80
0.90
1.00
1.10
1.20
1.30
1.40
1.50
1.60
1234567891011121314151617181920Sinuosity Reach
1936 1948 1959 1964 1970 1980 1989 2000 2011
King County River and Floodplain Management 35 April 2015
4.3 Lateral channel migration rates
As noted in Section 3.3.3, lateral channel migration rates were calculated as the distance
between channel locations in successive aerial photos divided by the time between photos.
Channel migration rates were calculated throughout each reach for time intervals between
successive aerial photos from 1936 to 2011 (Table 2) in two ways: using all measurements
and using eroding-only measurements. Channel migration rates calculated throughout each
reach are summarized for all measurements in Table 4 and for eroding-only measurements
in Table 5. The last two columns of each table report a time-weighted average value of
migration rates for 1936 to 1964 and for 1964 to 2011.
Table 4. Cedar River channel migration rates using all measurements.
Reach
1936
to
1948
1948
to
1959
1959
to
1964
1964
to
1970
1970
to
1980
1980
to
1989
1989
to
2000
2000
to
2011
1936
to
1964
1964
to
2011
1 1.0 1.0 1.9 2.1 0.9 1.2 0.8 0.5 1.1 1.0
2 0.9 1.8 3.8 3.3 1.5 1.0 2.0 0.6 2.4 1.6
3 1.3 2.6 6.2 3.8 2.0 1.9 1.8 0.7 2.7 1.9
4 2.0 4.8 5.3 5.3 8.5 3.0 4.3 2.0 3.7 4.7
5 2.8 3.5 3.2 2.7 2.9 2.7 2.5 1.0 3.2 2.3
6 2.6 8.4 7.1 5.4 2.3 3.2 1.8 2.8 5.7 2.9
7 4.9 5.5 7.0 3.9 2.0 3.1 1.8 0.6 6.1 2.1
8 1.5 2.0 5.8 3.5 2.5 1.7 2.1 2.7 2.5 2.4
9 2.0 3.8 2.9 4.6 2.8 1.8 1.5 2.5 2.9 2.8
10 3.1 4.0 2.8 2.7 1.8 2.3 1.1 0.8 3.4 1.6
11 4.5 4.9 3.7 4.1 2.3 2.3 1.9 1.0 4.5 2.1
12 3.3 3.1 2.2 2.2 0.6 2.2
13 3.6 2.4 2.7 1.9 0.9 2.1
14 2.7 2.6 2.2 0.8 0.6 1.6
15 1.9 3.5 3.8 2.2 1.0 2.4
16 1.7 1.5 1.9 1.6 0.8 1.5
17 3.0 1.8 3.2 2.8 1.4 2.4
18 2.0 2.6 2.3 1.6 0.9 1.8
19 2.7 1.7 2.2 1.3 0.8 1.6
20 2.1 1.4 2.0 0.7 0.7 1.3
Migration rates from each of the eight time periods calculated using all measurements
(Table 4) have varied through the study area and through time (Figure 16). The highest
migration rates are approximately 8 feet/year. These higher rates are common to reaches
or areas with less confinement or bank armoring (e.g., Reach 4 and part of Reach 6).
Migration rates through all reaches typically have declined through the period of this study.
Typical migration rates range from 2 feet/year to 7 feet/year during 1936 to 1964 and
range from 1 foot/year to about 5 feet/year during 1964 to 2011.
King County River and Floodplain Management 36 April 2015
Table 5. Cedar River channel migration rates using eroding-only measurements.
Reach
1936
to
1948
1948
to
1959
1959
to
1964
1964
to
1970
1970
to
1980
1980
to
1989
1989
to
2000
2000
to
2011
1936
to
1964
1964
to
2011
1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
2 1.0 1.5 4.8 3.8 1.8 1.2 2.2 0.7 2.8 1.9
3 1.4 3.1 6.2 4.9 2.2 1.9 2.1 0.9 3.2 2.2
4 2.6 5.4 5.7 5.9 11.7 2.8 4.9 2.2 4.5 6.4
5 1.8 4.4 3.3 2.8 3.8 2.7 2.6 1.1 3.5 2.5
6 3.1 8.5 7.6 7.6 3.1 4.9 1.8 3.6 6.2 3.3
7 1.8 4.7 7.3 5.1 2.2 3.7 2.2 0.8 6.7 2.2
8 1.7 2.5 5.8 3.9 3.1 2.3 2.4 2.6 2.9 2.7
9 2.0 8.6 3.7 4.1 2.8 1.3 1.6 2.9 4.6 2.9
10 3.3 4.0 3.2 2.7 2.4 2.9 1.7 1.0 3.9 2.0
11 4.4 5.5 3.0 4.6 2.4 2.9 2.5 1.2 5.3 2.6
12 3.0 3.1 2.5 2.4 1.0 2.3
13 3.6 2.6 3.6 2.2 1.7 2.5
14 2.9 3.2 4.1 1.2 1.1 2.0
15 2.5 3.5 3.8 2.2 1.5 2.7
16 2.3 1.7 2.2 1.8 1.1 1.7
17 3.2 2.5 3.9 2.7 1.3 2.6
18 2.8 2.8 2.6 2.1 1.1 2.2
19 3.6 1.9 2.8 2.0 1.1 2.0
20 2.8 1.9 2.4 0.9 1.1 1.6
King County River and Floodplain Management 37 April 2015
Figure 16. Cedar River channel migration rates using all measurements.
Time-weighted average migration rates (Table 5, Figure 17) moderate the variability in
migration rates evident through the eight time periods (Figure 16). However, overall
spatial and temporal trends in migration remain similar whether calculated in each time
period or as a time-weighted average. Migration rates based on eroding-only
measurements are consistently greater than rates based on all measurements, typically by
about 5 to 10 percent (Figure 17). The migration rates during 1964 to 2011 are lower than
those during 1936 to 1964.
0
1
2
3
4
5
6
7
8
9
1 2 3 4 5 6 7 8 9 1011121314151617181920Migration Rate (feet/year) Reach
1936 - 1948
1948 - 1959
1959 - 1964
1964 - 1970
1970 - 1980
1980 - 1989
1989 - 2000
2000 - 2011
King County River and Floodplain Management 38 April 2015
Figure 17. Cedar River weighted-average channel migration rates, using all measurements
and eroding-only measurements.
Migration rates also were calculated based on measurements taken only in unarmored
areas to evaluate the effect of bank armoring on channel migration (Appendix B). The
migration rates in unarmored areas based on all measurements (Appendix B, Table B-1 and
Figure B-1) have varied through the study area and through the eight time periods
similarly to channel migration rates in all areas (Table 4, Figure 16). The magnitudes of
channel migration rates in unarmored areas typically are greater than migration rates in all
areas (e.g., by 10 to 50 percent), although there is much variability in the differences in
migration rates in unarmored compared to all areas. In most reaches, the time-weighted
average rates in unarmored areas (Appendix B, Table B-1, Table B-2, and Figure B-2) are
within 10 percent of the time-weighted average rate based on measurements in all areas.
The few locations where migration rates in unarmored areas are notably greater than
those in all areas are in Reach 6, where rapid and expansive migration followed levee
removal at the Cedar Rapids site (RM 7.4), and in the largely unconfined and unarmored
Reach 9.
The general similarity between migration rates in unarmored areas and in all areas results
from different reasons during the 1936 to 1964 and the 1964-2011 periods. Bank
conditions in all areas and in unarmored areas were very similar during the 1936 to 1964
period because relatively little bank armoring had been constructed at that time (Figure 2).
Similarities of migration rates in all areas and in unarmored areas during the 1964 to 2011
period likely result because widespread bank armoring can reduce channel migration along
adjacent unprotected banks as well as at armored sites.
Eroding-only channel migration rates, both in all areas and in unarmored areas, have been
used in previous CMZ mapping studies on local rivers. Channel migration rates calculated
on the Tolt River (Shannon & Wilson 1991) and the Middle Green River (King County 1993)
provide local context for Cedar River channel migration rates. Both the Tolt River and the
0
1
2
3
4
5
6
7
8
9
1 2 3 4 5 6 7 8 9 1011121314151617181920Migration Rate (feet/year) Reach
1936-1964 All Msmts
1936-1964 Erod Only
1964-2011 All Msmts
1964-2011 Erod Only
King County River and Floodplain Management 39 April 2015
Middle Green River have migrating channels in post-glacial valleys, and both are affected
by the presence of dams. Both studies calculated migration rates using eroding-only
measurements; the Tolt River from all areas and the Middle Green River from unarmored
areas. Eroding-only channel migration rates on the Tolt River ranged from 2 feet/year to
10 feet/year and on the Middle Green River ranged from about 1 foot/year to 11 feet/year.
River channels in both the Tolt River and Green River study areas have less bank armoring
than the Cedar River study area. Typical eroding-only channel migration rates from all
areas on the Cedar River throughout the timeframe of 1964 to 2011 range from 2 feet/year
to about 6 feet/year. Migration rates on the Cedar River are comparable to these two local
examples.
4.4 Spatial variation in channel migration
Much of the study area exhibits confined channel conditions, as indicated by widespread
containment of the 1,800 cfs (annual 74 percent) and 2,800 cfs (annual 42 percent) flood
events. Containment of these frequent flows, and, in some locations, the 5,000 cfs (annual
10 percent) and larger floods, results in a decreased frequency and extent of overbank
flows, recruitment of gravel and large wood, bank erosion, and channel migration. These
conditions are typical throughout the study reaches except in unconfined areas such as
within Reach 4 (RM 5; 2011 landslide) and Reach 6 (RM 7.4; Cedar Rapids area).
The Cedar River appears to be generally efficient at moving coarse sediment from
Landsburg to I-405. In Reach 20 (RM 22) through Reach 18 (RM 17), the naturally steep
channel gradient and narrow valley bottom confinement combine to keep incoming
sediment in transport. In Reach 17 and downstream as well, pervasive bank armoring or
erosion-resistant geology plus containment of flows well above the threshold of coarse
sediment movement generally maintain conditions that favor coarse sediment transport.
From Reach 17 (RM 17) to Reach 2 (RM 3), the lack of a clear correlation between channel
gradient and sediment characteristics (Figure 5 and Figure 6) suggests that local variations
in factors such as channel confinement have a stronger influence than channel gradient on
sediment transport and deposition, and by extension, on bank erosion and channel
migration. The areas noted in the previous paragraph are example locations where
unconfined channels exhibit sediment deposition and active channel migration.
Large wood accumulations have the potential to influence and increase channel migration
activity (Brummer et al. 2006). However, the current amounts, densities, and distribution
of large wood (K. Akyuz, pers. comm. 2014) suggest that large wood presently is not a
significant factor regarding channel migration, at least not systemically. Large wood
accumulations within a reach typically increase local water surface elevations, and these
increases cause increased potential for avulsion and channel migration, depending on the
proximity of the large wood feature to a potential avulsion pathway. The location, presence,
and size of present-day large wood accumulations were considered when evaluating
potential avulsion sites for avulsion hazard in this study (Section 5.1.2).
Habitat restoration plans for endangered species recovery and other purposes have the
goal of increasing the number and size of large wood over time within the Cedar River. It is
King County River and Floodplain Management 40 April 2015
assumed that, as riparian reforestation projects mature, the amount of wood in the river
will increase. Potential future increases in in-channel large wood accumulations likely will
result in increased water surface elevations and the extent of potential channel migration,
locally at first and more systemically over longer periods.
4.5 Temporal changes in channel migration
The combination of flow regulation since 1914 and the widespread presence of bank
armoring since the 1960s has resulted in a narrowing of the average active channel width
by approximately 50 percent and a simplification of the channel pattern from
anabranching3 to single channel in most of the study area (Perkins 1994). With
simplification of channel pattern, channel migration by avulsion likely decreased through
time because of less opportunity for flows to access the multiple flow paths present in
anabranching channels.
The decrease in channel migration rates seen after 1964 (Figure 17) likely also results from
the proliferation of bank armoring in the 1960s. The effects of bank armoring on channel
migration rates persist to present day, with relatively minor lateral channel migration
observed after the January 2009 flow of 7,870 cfs (approximately an annual 3.3 percent
flood event) (Gendaszek at al. 2012).
3 Anabranching channel: A channel pattern that consists of multiple channels separated by stable islands
which are large relative to the size of the channels and which divide the flow up to and including bankfull
(Knighton 1998).
King County River and Floodplain Management 41 April 2015
5.0 CHANNEL MIGRATION HAZARDS ON
THE CEDAR RIVER
The findings from Section 4 are used in this chapter to predict future limits of channel
migration within the study area. The resulting identified channel migration hazard areas
are shown in the Cedar River CMZ map in Section 5.2.
5.1 Delineation of channel migration hazard areas
Channel migration hazards associated with each CMZ component are described in the
following subsections.
5.1.1 Historical Migration Zone
Historical active channels and the HMZ boundary are shown in Map 3. The HMZ is mapped
as a severe hazard area.
5.1.2 Avulsion Hazard Zone
Low-lying, frequently flooded areas evident in the elevation difference map (Map 4) that
met AHZ mapping criteria (Section 3.3.2) are listed in Table 6 and shown in Map 5,
Appendix A. Mapped AHZs are described in this section.
King County River and Floodplain Management 42 April 2015
Table 6. Areas mapped within the Avulsion Hazard Zone.
D/S
RM*
U/S
RM*
Bank**
Location
Description
Mapping criteria†: ALL must be met in order to map as AHZ Map
as
AHZ?
Criteria† for Severe: must meet ANY
Map as
Severe?
Low-lying Shorter Erodible substrate
Likely
route
Unvegetated/
scour
Low
Connection Indicators
6.80 6.95 LB Riverbend Lower
Yes, behind
facility Yes
Yes: Facility not DMA‡
and is <1 percent
flood elevation4 Yes Yes Yes No No Yes
8.95 9.25 LB
Large meander,
floodplain channel Yes Yes Yes Yes Yes No No No No
9.85 10.00 RB Near CRT€ 5B Yes Yes Yes Yes Yes Yes Yes Yes Yes
10.87 11.47 RB
Rainbow Bend;
existing low area Yes Yes Yes Yes Yes Yes No Yes Yes
10.87 11.16 RB
Rainbow Bend;
side channel to d/s
backwater area Yes Yes Yes Yes Yes Yes Yes Yes Yes
11.15 11.44 RB
Rainbow Bend;
side channel to
river Yes Yes Yes Yes Yes Yes Yes Yes Yes
11.21 11.41 RB
Rainbow bend; cut
off channel to
river Yes Yes Yes Yes Yes Yes Yes Yes Yes
13.16 13.44 LB Rutledge Johnson
Yes, behind
facility Yes
Yes: Facility not DMA‡
and is <1 percent
flood elevation4 Yes Yes Yes No Yes Yes
13.37 13.65 RB 13.65 to Taylor Crk Yes Yes Yes Yes Yes Yes Yes Yes Yes
13.37 13.89 RB Behind Getchman
Yes, behind
facility Yes
Yes: Facility not DMA‡
and is <1 percent
flood elevation4 Yes Yes Yes Yes
15.74 15.91 LB U/S Colemn-Lotto Yes Yes Yes Yes Yes Yes Yes Yes
15.83 16.2 RB Doris Creek Yes Yes Yes Yes Yes Yes Yes Yes
16.00 16.5 LB D/S of CRT Bridge Yes Yes Yes Yes Yes Yes Yes Yes Yes
16.95 17.09 LB U/S Youngs Yes Yes Yes Yes Yes Yes Yes
17.28 17.38 RB
Behind Orchard
Grove
Yes, behind
facility Yes
Yes: Facility not DMA‡
and is <1 percent
flood elevation4 Yes Yes No No No No
17.84 18.04 LB U/S of CRT Bridge Yes Yes Yes Yes Yes Yes Yes
King County River and Floodplain Management 43 April 2015
Table 6 footnotes:
* D/S = downstream; U/S= upstream.
** LB= left bank and RB = right bank when viewed downstream.
† See Section 3.3.2 for full description of mapping criteria.
‡ “Facility not DMA” = Facility does not meet Disconnected Migration Area mapping criteria.
4 “<1 percent flood elevation” = Top of facility is lower than the 1 percent flood water surface elevation
€ CRT = Cedar River Trail.
An AHZ is mapped along the left bank near RM 7 (Map 5A, Appendix A). The top elevation
of the Riverbend Levee at this site is lower in elevation than the water surface elevation of
the 10,300 cfs (annual 1 percent) flood, and this levee is not likely to restrain channel
migration. This severe AHZ is mapped through Cavanaugh Pond.
A low-lying area that runs generally parallel to the main channel along the left bank near
RM 9 is mapped as a moderate AHZ (Map 5B, Appendix A). A present-day side channel that
was occupied by the mainstem as recently as the 1970s is mapped as a severe AHZ along
the right bank near RM 10 (Map 5B, Appendix A). Although this former channel is within
the HMZ, the delineated severe AHZ extends landward of the HMZ.
There are two floodplain channels that were excavated along the right bank near RM 11 as
part of the Rainbow Bend levee removal project. These two excavated channels plus two
existing low-lying areas onsite are mapped as severe AHZs (Map 5C, Appendix A).
Existing floodplain channels and the downstream end of Taylor Creek located landward of
the right bank Getchman levee and the left bank Rutledge-Johnson levee (RM 13 to RM 14)
are mapped as severe AHZs (Map 5D, Appendix A). The top elevation of both levees is
lower than the water surface elevation of the 10,300 cfs (annual 1 percent) flood, and
neither levee is likely to restrain channel migration. An existing right bank floodplain
channel located between the Getchman and Jan Road levees near RM 13.6 has a direct, low-
elevation surface connection to the Cedar River and is mapped as severe hazard (Map 5D,
Appendix A).
There is a low-lying floodplain channel along the left bank near RM 15.8 and more than one
such floodplain channels near RM 16.5 that have a direct, low-elevation connection to the
mainstem. All are mapped as severe AHZs (Map 5E, Appendix A). A right bank side channel
named Doris Creek located between RM 16.2 and RM 15.9 maintains a direct low-elevation
surface connection to the mainstem with year-round flow; it is mapped as a severe AHZ
(Map 5E, Appendix A).
There are two low-lying floodplain channels along the left bank that have a direct, low-
elevation connection to the mainstem channel; one is near RM 17 and one is near RM 18
(Map 5F, Appendix A); both areas are mapped as severe AHZs. A low-lying area landward
of the right bank Orchard Grove levee near RM 17.4 is an AHZ because the top elevation of
this levee is lower than the water surface elevation of the 10,300 cfs and this levee is not
likely to restrain channel migration (Map 5F, Appendix A). This AHZ is a moderate hazard
area because the landward area does not meet any of the criteria to be mapped as a severe
AHZ.
King County River and Floodplain Management 44 April 2015
5.1.3 Erosion Hazard Area/Erosion Setback
The 1964-2011 weighted average channel migration rate calculated using eroding-only
measurements (Table 5) is taken to be the representative lateral migration rate for the
reach in which it was calculated. The 1964-2011 timeframe was used because it produces
long-term average migration rates, which are appropriate to the prediction of channel
migration hazard over multiple decades. It also encompasses the period through which
bank armoring and flow regulation, representative of current conditions, have been in
place. The migration rates using eroding-only measurements also are representative
because they use measurements along both armored and unarmored locations, which
reflect present channel conditions. Channel migration rates calculated in unarmored areas
were not used because they do not include armored locations, which are pervasive under
present conditions.
EHA/ES widths calculated for moderate hazard areas and severe hazard areas in valley-
bottom alluvium using eroding-only migration rates are summarized in Table 7. The severe
hazard ES width is delineated as either 25 years times the channel migration rate in
column 2 of this table applied to the HMZ or 50 years times the same migration rate
applied to the 2011 Active Channel, whichever distance is more landward. The moderate
hazard area ES width is delineated in the same way as the severe hazard area ES using 50
years and 100 years. In addition to applying these setback widths to the HMZ and the 2011
Active Channel, an ES also was applied to the delineated AHZ to a width based on 25 to 50
years of lateral migration (as described in Section 3.3.3.2).
King County River and Floodplain Management 45 April 2015
Table 7. Erosion Hazard Area/Erosion Setback widths.
Reach
Channel
Migration
Rate (ft/year)
EROSION SETBACK WIDTHS (feet)
SEVERE HAZARD AREA MODERATE HAZARD AREA
Feet from
HMZ
Feet from 2011
Active Channel
Feet from
HMZ
Feet from 2011
Active Channel
25 years 50 years 50 years 100 years
1 0.0 0 0 0 0
2 1.9 46 93 93 185
3 2.2 54 108 108 216
4 6.4 161 321 321 642
5 2.5 62 125 125 250
6 3.3 82 165 165 330
7 2.2 55 111 111 221
8 2.7 68 135 135 270
9 2.9 73 146 146 291
10 2.0 50 99 99 199
11 2.6 64 128 128 257
12 2.3 58 115 115 231
13 2.5 63 126 126 252
14 2.0 50 100 100 200
15 2.7 68 136 136 271
16 1.7 42 83 83 166
17 2.6 65 131 131 261
18 2.2 55 110 110 220
19 2.0 51 102 102 203
20 1.6 41 81 81 163
There was a measureable, consistent, channel migration that progressed in the
downstream (down-valley) direction in addition to lateral channel migration at
approximate RM 7.4 and RM 9.8. At these locations, a down-valley component was added
to the EHA/ES.
The lateral migration rate from Table 5 was not a representative migration rate in some
locations because the substrate was not valley-bottom alluvium (i.e., the material in which
Table 5 migration rates were calculated), or the land surface elevation at that location was
much higher than the valley bottom within which that rate was calculated, or both. Specific
locations where these non-representative conditions exist are as follows:
x a left bank landslide site at RM 3;
x the 2001 landslide site on the right bank at approximate RM 5;
x an alluvial fan on the right bank at approximate RM 7.4;
x a terrace mapped as mass-wasting material on the right bank at about RM 10.5;
x a terrace composed of old alluvium on the right bank at about RM 12.5;
King County River and Floodplain Management 46 April 2015
x an alluvial terrace on the right bank at RM 15.35; and
x a landslide site on the right bank at RM 17.7.
At these locations, an EHA/ES was mapped using lateral migration rates that were
calculated specific to that site. The lateral migration rates at these sites were lower than
those in nearby valley-bottom alluvium.
5.1.4 Erosion Hazard Area/Geotechnical Setback
An EHA/GS was added to the outer edge of the EHA/ES at several locations where the
EHA/ES encountered a landform that was greater in height than 20 feet above Ordinary
High Water, as described in Section3.3.4. The EHA/GS is included in the CMZ delineated in
Section 5.2.
5.1.5 Disconnected Migration Area
Legally existing publicly maintained levees, revetments, and other infrastructure within
King County or the City of Renton that met the mapping criteria in Section 3.3.5 are
summarized in Table 8. Areas landward of such structures are eligible to be mapped as a
DMA.
King County River and Floodplain Management 47 April 2015
Table 8. Assumed barriers to channel migration.
D/S RM U/S RM
River
Bank Name of Structure Type of Structure(s)
0.00 1.66 Both Cedar River 205 Flood Control
Project
Levees and floodwalls within City of
Renton
1.99 13.31 Either SR 169, at several locations State highway
2.74 2.78 Left Haddad Revetment within City of Renton
2.77 2.84 Right Tabor-Crowall Revetment within City of Renton
3.33 3.51 Right Brodell Revetment within City of Renton
4.11 4.21 Right Erickson Revetment within City of Renton
4.26 4.31 Right Maplewood Golf Course Revetment within City of Renton
4.27 4.41 Left Lower Elliott Park Revetment within City of Renton
4.77 4.89 Left Upper Elliott Park Levee within City of Renton
7.36 7.54 Right Cedar Rapids Right Bank* Levee
10.32 10.41 Left Belmondo Levee
11.47 11.51 Right Rainbow Bend Upstream Revetment
11.67 11.94 Left SE 184th Str Sole-access county road
12.67 12.82 Left SE 193rd Str to 216th Ave SE Sole-access county road
14.04 14.06 Both SR 169 bridge State highway bridge abutments
14.97 15.16 Left SE Bain Rd Sole-access county road
14.75 14.81 Right SE 214th Str to 221st Ave SE Sole-access county road
14.91 15.16 Left SE Bain Rd Sole-access county road
15.12 15.16 Both SR 18 bridges State highway bridge abutments
15.22 15.26 Both SR 169 bridge State highway bridge abutments
15.81 15.89 Right Dorre Don Way SE Sole-access county road
15.99 16.34 Right Dorre Don Way SE Sole-access county road
16.55 16.58 Left Elkington Cedar Trail Bridge Revetment
16.95 17.05 Right Dorre Don Way SE Sole-access county road
17.19 17.53 Right Upper Dorre Don Way SE Sole-access county road
*Mapped as a barrier to channel migration for Severe Hazard Area only.
5.2 Channel migration hazard maps
Areas within the Historical Migration Zone, Avulsion Hazard Zone, and Erosion Hazard
Area (including the Erosion Setback and Geotechnical Setback) were combined to form an
unconstrained channel migration zone, as shown in Map 6, Appendix A. The unconstrained
CMZ does not recognize artificial constraints and therefore predicts channel migration in
the absence of levees, revetments, and structures such as the Cedar River Trail, SR 169, and
bridge features.
In a majority of study reaches, the width of the HMZ constitutes most of the width of the
unconstrained CMZ. Reaches where this relationship holds true include those that are
steep, confined, or both (e.g., Reaches 20-16, 14, 13, 5, 3, 2, and 1). In reaches where the
width of the HMZ does not constitute most of the width of the unconstrained CMZ (e.g.,
Reaches 15, 12, 11, 8, and 6), typically an AHZ is present, or there has been a down-valley
King County River and Floodplain Management 48 April 2015
component mapped in the EHA/ES, or both. The width of the HMZ may or may not
constitute most of the width of the unconstrained CMZ in unconfined reaches with high
channel migration rates (e.g., Reach 4 and Reach 6).
A channel migration zone map was prepared by modifying the unconstrained CMZ in two
ways. First, the effects of artificially constructed constraints on channel migration were
recognized by mapping a Disconnected Migration Area (DMA) based on the information
from Table 8. Structures listed in Table 8 were assumed to be barriers to channel
migration, and the outer edge of the CMZ was drawn along the boundaries of these
structures. Areas landward of these structures were considered DMAs and removed from
the unconstrained CMZ, with one exception: the severe hazard area along the right bank at
RM 7.4 in Reach 6 landward of the Cedar Rapids Right Bank levee was reduced in width to
match the boundary of the bank armoring. The severe hazard width was reduced at this
location because this structure met the criteria for top elevation being higher than that of
the annual 1 percent flood and for its construction standards but not for the possibility of
erosion landward of the structure. The outer extent of the CMZ remains unaltered at this
location and is mapped as a moderate hazard area.
In accordance with WAC and King County code provisions (cited in Section 3.3.5), artificial
structures in unincorporated King County were mapped as barriers to migration only if
they are publicly maintained, built higher than the annual 1 percent flood elevation, meet
construction standards, and the channel is unlikely to migrate landward of the structure
(Section 3.3.5). The majority of levees and revetments maintained by King County within
unincorporated King County were not mapped as barriers to channel migration because
they were not built higher than the elevation of the annual 1 percent flood and were not
likely to restrain channel migration. All publicly maintained structures in the City of Renton
were mapped as barriers to migration. No privately maintained structures were mapped as
barriers to channel migration. If an artificial structure did not meet all criteria necessary to
map a DMA, the width of both severe and moderate hazard areas were left unrevised in
order to recognize the channel migration hazard landward of that structure.
The second modification to the unconstrained CMZ map was to delineate a severe hazard
area and moderate hazard area within the CMZ. This delineation recognizes that channel
migration hazard is not equal throughout the CMZ. Channel migration hazard is greater for
sites that are near the current channel and potential avulsion pathways.
Severe hazard areas are composed of the HMZ, severe AHZs, and portions of the EHA. The
2011 (present-day) active channel is located within the HMZ, and therefore the active
channel always is located within the severe hazard area. The severe hazard area occupies
most of the width of the CMZ throughout the study area except at RM 14.5 and RM 19.25,
where the moderate-hazard EHA/GS is relatively wide (Map 6, Appendix A). Severe hazard
area widths upstream of the channelized Reach 1 range from 110 feet at RM 20 where both
river banks are bedrock to about 1,000 feet in the naturally unconfined Reach 4. The
moderate hazard area lies between the severe hazard area and the outer boundary of the
unconstrained CMZ.
King County River and Floodplain Management 49 April 2015
The Cedar River channel migration zone is presented in Map 7, Appendix A.
The Cedar River CMZ includes most of the valley floor in the naturally confined upstream
part of this study area (Reaches 20 through 18). Further downstream, the CMZ includes
most of the valley floor where it is not cut off by major infrastructure (e.g., SR 169) in
reaches that exhibit historically active channel migration or are subject to avulsion hazards,
or both (Reaches 15, 12, 10, 9, 8, 6 and 4). The CMZ along most of the length of other
reaches covers a relatively narrow portion of the valley floor.
5.3 Summary, conclusions
Natural conditions set the stage for channel migration in the study area. Over the past
13,000 years, the Cedar River has incised through glacial and non-glacial sediments,
deposited alluvial sediments, and migrated across its alluvial valley bottom. Artificial
conditions imposed on the natural setting over the past 50 to 100 years have altered
channel conditions and channel migration characteristics through most of the study area.
Modifications to the flow regime since circa 1914 have resulted in containment of small to
moderate flood events as well as a simplified channel pattern. Widespread bank armoring
installed in the 1960s, along with other constraining infrastructure, confine much of the
river channel length and have decreased channel migration rates. With flow regulation
assumed to continue as it has for the past century, channel confinement and bank armoring
emerge as the prominent variables presently affecting channel migration in this study area.
The river has a single-channel pattern and lower lateral migration rates in confined and
armored areas than in unconfined or unarmored areas. However, the potential for active
channel migration remains high should bank armoring fail or be removed.
In the few areas that are naturally unconfined or recently have had bank armoring
removed, the following channel conditions have been observed:
x Lateral migration rates typically are higher than in confined areas.
x A multiple-channel pattern prevails and gravel bars are bare and active, all of which
suggest sediment deposition.
x Conditions that favor avulsion may be present.
x Channel expansion typically occurs after a triggering event such as avulsion or levee
removal.
x Greater numbers of large wood exist than in confined areas.
In addition to using the Cedar River CMZ map to regulate land use in affected channel
migration hazard areas, the CMZ map and findings of this study will inform planning and
development of capital flood risk reduction projects via the Cedar River Corridor process.
There is potential to decrease flood risk and increase floodplain connectivity in mapped
channel migration hazard areas by acquiring at-risk properties, removing constructed bank
armoring and allowing channel migration to proceed in a less constrained condition than
currently exists. This potential would be greatest in areas where channel gradient is
moderate and naturally erosion-resistant riverbanks are absent or do not dominate. Such
conditions exist in Reaches 16, 15, 12, 11, 10, 7, 6, 5 and 4 of this study area. If channel
King County River and Floodplain Management 50 April 2015
migration predicted for conditions following a bank-armor removal project is significantly
different from present conditions, the relevant portion of the CMZ map may be updated, as
described in Section 1.3.
This study’s use of historical information to predict existing and future hazard is consistent
with accepted practices and guidance (King County 2014; Ecology 1993-2014). Because
some factors affecting channel migration are stochastic in nature, the channel may not
occupy all parts of the mapped CMZ within the next 100 years. However, there also is a low
but real possibility that the channel could occupy portions of the valley floor beyond the
limits of the mapped CMZ. As such, all parts of the alluvial valley bottom, excluding high
terraces, should be considered to have a low level of channel migration hazard.
King County River and Floodplain Management 51 April 2015
6.0 REFERENCES
Akyuz, K. 2014. Senior Ecologist, King County Department of Natural Resources and Parks,
Rivers and Floodplain Management Section. Personal communication.
Booth, D.B. 1995. Geologic map of the Maple Valley quadrangle, King County Washington.
Miscellaneous Field Studies Map MF-2297. U.S. Geological Survey, Reston, VA.
Brummer, C.J., T.B. Abbe, J.R. Sampson, and D.R. Montgomery. 2006. Geomorphology. 80:
295-309. Influence of vertical change associated with wood accumulations on
delineating channel migration zones, Washington, USA.
Collins, B.D. , A. Sheikh, and C. Kiblinger. 2003. Historical river channel data for the Cedar
River. Unpublished report to King County Department of Natural Resources and
Parks. 14 pp.
Collins, B.D., and D.R. Montgomery. 2011. The legacy of Pleistocene glaciation and the
organization of lowland alluvial process domains in the Puget Sound region.
Geomorphology 126: 174-185.
Federal Emergency Management Agency. 2005. Flood Insurance Study, King County
Washington and Incorporated Areas. Washington D.C.
Federal Emergency Management Agency. 2013. Model ordinance for floodplain
management under the National Flood Insurance Program and the Endangered
Species Act. Produced by Federal Emergency Management Agency Region 10.
Bothell, WA
Fox, M., and S. Bolton. 2007. A regional and geomorphic reference for quantities and
volumes of instream wood in unmanaged forest basins of Washington State. North
American Journal of Fisheries Management 27, 342-359.
Gendaszek, A.S., C.S. Magirl, and C.R. Czuba. 2012. Geomorphic response to flow regulation
and floodplain alterations in the gravel-bedded Cedar River, WA, USA.
Geomorphology. 179, 258-268.
Harper, Houf, and Righellis. 2002. Cedar River Flood Analysis Report. River Mile 5 to 22.
Unpublished report to King County Department of Natural Resources and Parks.
Prepared by Harper, Houf, Righellis, Inc. Las Vegas, NV. 2pp.
Jones, J.L. 2006. Side channel mapping and fish habitat suitability analysis using LiDAR
topography and orthophotography. Photogrammetric Engineering and Remote
Sensing 71, 1202-1206.
King County River and Floodplain Management 52 April 2015
King County. 1993. Cedar River current and future conditions report. Unpublished report
by King County Department of Public Works, Surface Water Management Division.
Seattle, WA.
King County. 2006. Flood hazard management plan: King County, Washington. King County
Department of Natural Resources and Park, Water and Land Resources Division.
Seattle, WA.
King County, 2012. King County Comprehensive Plan 2012. King County Department of
Permitting and Environmental Review, Chapter 8, Section II.L.
King County. 2013. 2013 flood hazard management plan update: King County, Washington.
King County Department of Natural Resources and Parks, Water and Land
Resources Division. Seattle, WA.
King County. 2014. King County channel migration public rule. Chapter 21A-24, Rules and
regulations of the Department of Permitting and Environmental Review and
Department of Natural Resources and Parks. Critical Areas: Designation,
Classification and Mapping of Channel Migration Zones. Amended March 31, 2014.
Knighton, D. 1998. Fluvial forms and processes; a new perspective. John Wiley and Sons,
Inc. New York.
Leopold, L.B. , M.G. Wolman, and J.P. Miller. 1964. Fluvial processes in geomorphology. W.H.
Freeman and Company. San Francisco.
Mullineaux, D.R. year? Geology of the Renton, Auburn, and Black Diamond quadrangles,
King County, Washington. Professional Paper. U.S. Geological Survey, 672.
Washington, D.C.
National Marine Fisheries Service. 2008. Implementation of the National Flood Insurance
Program in the State of Washington Phase One Document - Puget Sound Region.
NMFS Tracking Number NWR-2006-472. National Oceanic and Atmospheric
Administration, National Marine Fisheries Service, Northwest Region.
Nelson, L. 1971. Sediment transport by streams in the Snohomish River basin, Washington:
October 1967 – June 1969: U.S. Geological Survey OpenFile Report 71-213.
Northwest Hydraulic Consultants. 2001. Lower Cedar River Sedimentation Analysis of
Existing Data, Final Report. Unpublished report prepared for the City of Renton.
Prepared by Northwest Hydraulic Consultants, Seattle WA. 58 pp.
Northwest Hydraulic Consultants. 2011. Cedar River Survey Data 2011. Unpublished report
prepared for the City of Renton. Prepared by Northwest Hydraulic Consultants,
Seattle WA. 101pp.
King County River and Floodplain Management 53 April 2015
O’Connor, J.E., M.A. Jones, and T.L. Haluska. 2003. Flood plain and channel dynamics of the
Quinalt and Queets Rivers, Washington, U.S.A. Geomorphology 51, 31-59.
Perkins, S.J. 1994. The shrinking Cedar River – channel changes following flow regulation
and bank armoring. Proceedings, Effects of human-induced changes on hydrologic
systems. 1994 Annual Summer Symposium, American Water Resources Association,
MD. Pp 649-658.
Perkins Geosciences and Harper Houf Righellis, Inc. 2002. Cedar River gravel study phase 2
report. Unpublished report to U.S. Army Corps of Engineers, Seattle District Office
and Jones & Stokes, Bellevue Washington. 67 pp.
Rapp, C., T.A. Abbe. 2003. A framework for delineating channel migration zones.
Washington Department of Ecology Publication 03-06-027. Olympia, WA.
Simon, A. 1989. A model of channel response in disturbed alluvial channels. Earth Science
Processes and Landforms 14, 11-26.
U.S. Army Corps of Engineers. 1997. Draft technical appendices to the Cedar River Section
205 study. Seattle District, Army Corps of Engineers.
WA Department of Ecology. 1994-2014. Washington Department of Ecology, Shorelands
and Environmental Assistance Program Channel Migration Assessment website:
http://www.ecy.wa.gov/programs/sea/sma/cma/index.html
Watershed Sciences and Engineering. 2013. Cedar River interactive mapping project model
and mapping development. Unpublished technical memorandum. 13 pp. August 21,
2013. HEC-RAS hydraulic model. Seattle, WA.
King County River and Floodplain Management 54 April 2015
7.0 APPENDIX A
Map 1. Publicly maintained levees and revetments
Map 2. Generalized geologic map of the study area
Map 3. Historical channels and Historical Migration Zone (HMZ)
Map 4. Elevation difference (water surface at 5,000 cfs and surface topography)
Map 5. Avulsion Hazard Zone
Map 6. Unconstrained Channel Migration Zone
Map 7. Cedar River Channel Migration Zone
Maps 1 through 7 are included after Appendix B.
King County River and Floodplain Management 55 April 2015
8.0 APPENDIX B
Table B-1. Channel migration rates in unarmored areas using all measurements.
Reach
1936
to
1948
1948
to
1959
1959
to
1964
1964
to
1970
1970
to
1980
1980
to
1989
1989
to
2000
2000
to
2011
1936
to
1964
1964
to
2011
1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
2 0.9 1.9 3.9 3.4 1.5 1.0 2.1 0.6 2.5 1.6
3 1.3 2.6 6.3 3.8 1.7 1.3 1.8 0.6 2.7 2.3
4 2.0 4.8 5.3 7.0 1.7 3.6 4.6 1.8 3.7 5.1
5 2.9 3.6 2.8 2.9 2.9 3.4 2.1 1.1 3.4 2.6
6 2.8 8.8 8.9 8.6 3.7 5.5 1.7 6.9 6.1 5.0
7 4.4 5.3 4.5 2.7 1.4 1.9 1.4 0.9 5.3 1.6
8 1.6 2.1 6.8 4.4 2.4 1.7 2.4 3.5 2.7 2.8
9 1.7 4.3 2.8 5.5 4.5 2.5 0.9 2.7 3.0 3.6
10 2.1 4.3 3.7 2.3 2.9 4.8 0.1 0.2 3.4 1.9
11 4.5 4.9 4.0 4.4 2.1 2.3 1.8 1.0 4.5 2.1
12 1.5 2.9 2.5 2.2 0.6 1.9
13 2.7 2.5 2.2 2.1 1.0 2.0
14 2.6 2.6 2.5 0.9 0.7 1.7
15 1.8 4.4 5.0 4.0 1.3 3.1
16 2.4 1.8 2.4 1.2 1.3 1.7
17 3.0 1.8 3.2 2.8 1.4 2.4
18 1.7 2.4 2.4 1.6 0.9 1.8
19 3.1 1.6 2.1 1.4 0.9 1.7
20 2.3 1.3 2.1 0.7 0.8 1.3
King County River and Floodplain Management 56 April 2015
Table B-2. Channel migration rates in unarmored areas using eroding-only measurements.
Reach
1936
to
1948
1948
to
1959
1959
to
1964
1964
to
1970
1970
to
1980
1980
to
1989
1989
to
2000
2000
to
2011
1936
to
1964
1964
to
2011
1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
2 1.1 1.5 5.0 3.8 1.8 1.2 2.3 0.7 3.0 1.9
3 1.4 3.1 6.3 4.9 2.0 1.4 1.9 0.8 3.1 2.6
4 2.6 5.4 5.7 7.8 3.9 1.4 5.7 1.8 4.5 5.4
5 1.8 4.6 3.4 3.2 3.9 3.4 2.2 1.3 3.9 2.5
6 3.1 9.0 9.3 13.2 4.6 5.5 1.9 9.3 6.6 5.9
7 1.8 5.7 3.8 3.5 2.0 2.5 1.9 1.2 4.8 2.0
8 1.5 2.6 6.8 4.6 2.7 2.1 2.5 2.7 2.9 2.8
9 1.6 8.6 3.7 3.4 4.5 3.6 3.5 4.6 3.6
10 2.6 5.0 3.6 2.3 2.9 4.8 0.7 0.2 4.3 2.3
11 4.4 5.5 3.0 4.9 2.1 2.7 2.5 1.2 5.3 2.6
12 1.8 2.9 3.3 2.5 1.3 2.3
13 2.7 2.7 3.0 2.5 1.8 2.4
14 3.0 2.7 4.1 1.4 1.0 2.1
15 1.8 4.4 4.5 4.0 3.2 3.6
16 3.1 1.8 2.4 1.5 1.6 1.9
17 3.2 2.5 3.9 3.1 1.3 2.6
18 2.5 2.7 2.8 2.1 1.1 2.2
19 4.0 1.7 2.8 2.0 1.2 2.1
20 2.9 1.2 2.1 0.9 1.2 1.7
King County River and Floodplain Management 57 April 2015
Figure B-1. Cedar River channel migration rates in unarmored areas using all measurements.
Figure B-2. Cedar River weighted-average channel migration rates in unarmored areas using all
measurements and in eroding-only measurements.
0
1
2
3
4
5
6
7
8
9
1 2 3 4 5 6 7 8 9 1011121314151617181920Migration rate (ft/yr) Reach
1936 - 1948
1948 - 1959
1959 - 1964
1964 - 1970
1970 - 1980
1980 - 1989
1989 - 2000
2000 - 2011
0
1
2
3
4
5
6
7
8
9
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20Migration Rate (ft/yr) Reach
1936-1964 All Msmts
1936-1964 Erod Only
1964-2011 All Msmts
1964-2011 Erod Only
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
Cedar River 205
Flood Control Project
Cummins
1965
Lund
1965
Tobacco-Dotson
1965
Haddad
1966
Maplewood
Golf Course
1965?
Cedar Trail 5
Elliot
Brg
1965
Cedar
Trl 1
Camp Freeman
1970
Orting Hill
Cedar
Rapids R
Belmondo
Riverbend
Lower Ext.
1965?Cedar
Trl 2
Erickson
1963
Tabor-Crowall
Cedar
Trail 4Cedar Trl 3
Progressive
Investment
1963
Littlefield
1965
Upper
Elliot Park
1977?
Herzman
1965
Lower Elliot
Park
Person
1972
Buck's
Curve
1963?Cedar
Trl 5B
Brodell
1966
Cedar
Rapids L
WPA
1963?
Riverbend Upper
Riverbend
Lower
1965
Cook-Jeffries
1963
Cedar
Trail 6
Brassfield
Maxwell Guth
Punnett
Briggs
1968
Scott-Indian
Grove
1964
King CountyRentonKi ng Cou
nt
y
Renton
1 | 2
2 | 3
6 | 7
5 | 6
7
|
8
3 | 4
9
|4 | 5 8
|
9
10
0
5
7
6
9
2 3
11
8
1
4
§¨405
Ü
Legend
!(River Mile
City Boundaries
Levees and Revetments
Reach Boundaries
2011 Active Channel
Valley Wall
Streets
Cedar River
Map 1. Publicly maintained
levees and revetments
The information included on this map has been compiled by
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change without notice.
King County makes no representations or warranties,
express or implied, as to accuracy, completeness,
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!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
!(
Rainbow
Bend US
Bain
Road
Seppi/Safe US
1965
Petorak Wadhams
1973
Edwards
1967
Elkinton-Cedar Trl Brg
Cummins
1965
Rawson
1968
Ahlquist
1965
Bain Road Bridge
Cedar
Trail 5
Cedar
Trl 7
Young
Dorre
Don Rd
Kazzka
1963
Ramon
1962
Belmondo
Mitchell
1963
Lions
Club
1962
Byer's Curve
Banchero
Barnes
1965?Lower Bain Road
1966
Cedar
Trl 8
Littlefield
1965
Arcadia Nobel
1962
Coleman-Lotto
1969
Cedar
Trl 5B
Cedar
Trl 9
Rutledge
Johnson
Jan
Road
1962
Mcdonald
1965
Dorre Don
Lower
1964
Royal
Arch
1966
Rhode
Cedar
1965
WPA
1963?
Dorre Don
Upper
1963
Orchard
Grove
Getchman
Cedar
Trail 6
18 | 19 19 | 2013 | 14
1
5
|
1
6
17 | 1812 | 1316 | 1714 | 151
1
|
1210 | 11
8
9
|
1
08
|
9
20
10
15
22
19
12
14
21
18
11
16
13
20
17
¬«18
Ü
Cedar River Channel Migration Study - April 2015
APRIL 2015
010.5
Miles
!(
!(
!(
!(
!(
!(
!(
!(
!(!(
!(
!(
!(
!(
!(
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!(
!(
!(
!(
!(
!(
!(
10
0
5
15
22
7
19
12
6
9
14
21
2
18
3
11
16
8
1
13
20
4
17
¬«18
¬«167
§¨405
Covington
King
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Ü
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Older Alluvium (Qoal)
Glacial Deposits
Recessional Outwash (Qvr)
Ice Contact (Qvi)
Advance Outwash and other
deposits (Qvu, Qva, Qu)
Till (Qvt)
Pre-Fraser deposits (Qpf)
Bedrock
Bedrock (Ts, Tp, Ti, Tpr)
Cedar River
Map 2. Generalized geologic
map of the study area
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Panel 3 of 8
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Cedar River Channel Migration Study - April 2015
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Panel 1 of 8
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Cedar River Channel Migration Study - April 2015
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Map 4. Elevation difference
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2011 LIDAR
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Elevation Difference
(feet)
-0 to -0.5
-0.51 to -1
-1.01 to -2
-2.01 to -3
-3.01 to -4
-4.01 to -5
-5.01+
Panel 4 of 8
Map 4. Elevation difference
(water surface at 5,000 cfs and
surface topography)
2011 LIDAR
Cedar River Channel Migration Study - April 2015
The information included on this map has been compiled by
King County staff from a variety of sources and is subject to
change without notice.
King County makes no representations or warranties,
express or implied, as to accuracy, completeness,
timeliness, or rights to the use of such information.
This document is not intended for use as a survey product.
King County shall not be liable for any general, special,
indirect, incidental, or consequential damages including, but
not limited to, lost revenues or lost profits resulting from the
use or misuse of the information contained on this map.
Any sale of this map or information on this map is prohibited
except by written permission of King County.
APRIL 2015
!(!(!(11 | 12
10 | 117 | 8
9 | 10
8 | 9
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12
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Feet
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Cedar River
Legend
!(River Mile
City Boundaries
Reach Boundaries
Elevation Difference
(feet)
-0 to -0.5
-0.51 to -1
-1.01 to -2
-2.01 to -3
-3.01 to -4
-4.01 to -5
-5.01+
Panel 5 of 8
Map 4. Elevation difference
(water surface at 5,000 cfs and
surface topography)
2011 LIDAR
Cedar River Channel Migration Study - April 2015
The information included on this map has been compiled by
King County staff from a variety of sources and is subject to
change without notice.
King County makes no representations or warranties,
express or implied, as to accuracy, completeness,
timeliness, or rights to the use of such information.
This document is not intended for use as a survey product.
King County shall not be liable for any general, special,
indirect, incidental, or consequential damages including, but
not limited to, lost revenues or lost profits resulting from the
use or misuse of the information contained on this map.
Any sale of this map or information on this map is prohibited
except by written permission of King County.
APRIL 2015
!(!(!(13 | 1412 | 1314 | 1
5
11 | 12
15
14
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Feet
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Cedar River
Legend
!(River Mile
City Boundaries
Reach Boundaries
Elevation Difference
(feet)
-0 to -0.5
-0.51 to -1
-1.01 to -2
-2.01 to -3
-3.01 to -4
-4.01 to -5
-5.01+
Panel 6 of 8
Map 4. Elevation difference
(water surface at 5,000 cfs and
surface topography)
2011 LIDAR
Cedar River Channel Migration Study - April 2015
The information included on this map has been compiled by
King County staff from a variety of sources and is subject to
change without notice.
King County makes no representations or warranties,
express or implied, as to accuracy, completeness,
timeliness, or rights to the use of such information.
This document is not intended for use as a survey product.
King County shall not be liable for any general, special,
indirect, incidental, or consequential damages including, but
not limited to, lost revenues or lost profits resulting from the
use or misuse of the information contained on this map.
Any sale of this map or information on this map is prohibited
except by written permission of King County.
APRIL 2015
!(
!(
!(
!(
!(
18 | 1915
|
1617 | 1816 | 1714 | 1519
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Cedar River
Legend
!(River Mile
City Boundaries
Reach Boundaries
Elevation Difference
(feet)
-0 to -0.5
-0.51 to -1
-1.01 to -2
-2.01 to -3
-3.01 to -4
-4.01 to -5
-5.01+
Panel 7 of 8
Map 4. Elevation difference
(water surface at 5,000 cfs and
surface topography)
2011 LIDAR
Cedar River Channel Migration Study - April 2015
The information included on this map has been compiled by
King County staff from a variety of sources and is subject to
change without notice.
King County makes no representations or warranties,
express or implied, as to accuracy, completeness,
timeliness, or rights to the use of such information.
This document is not intended for use as a survey product.
King County shall not be liable for any general, special,
indirect, incidental, or consequential damages including, but
not limited to, lost revenues or lost profits resulting from the
use or misuse of the information contained on this map.
Any sale of this map or information on this map is prohibited
except by written permission of King County.
APRIL 2015
!(
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!(
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21
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Feet
Document Path: \\kc.kingcounty.lcl\dnrp\WLRD\RFMS\FLOOD\Flood Drive Files\Cedar-Samm\FLD202 Cedar CMZ Study\Final_to_DPER\Maps\Map4_Cedar_elevation_difference.mxd
Cedar River
Legend
!(River Mile
City Boundaries
Reach Boundaries
Elevation Difference
(feet)
-0 to -0.5
-0.51 to -1
-1.01 to -2
-2.01 to -3
-3.01 to -4
-4.01 to -5
-5.01+
Panel 8 of 8
Map 4. Elevation difference
(water surface at 5,000 cfs and
surface topography)
2011 LIDAR
Cedar River Channel Migration Study - April 2015
The information included on this map has been compiled by
King County staff from a variety of sources and is subject to
change without notice.
King County makes no representations or warranties,
express or implied, as to accuracy, completeness,
timeliness, or rights to the use of such information.
This document is not intended for use as a survey product.
King County shall not be liable for any general, special,
indirect, incidental, or consequential damages including, but
not limited to, lost revenues or lost profits resulting from the
use or misuse of the information contained on this map.
Any sale of this map or information on this map is prohibited
except by written permission of King County.
APRIL 2015
Legend
!(River Mile
Reach Boundaries
Levees and
Revetments
Streets
2011 Active Channel
Historical Migration
Zone Boundary
Severe AHZ
Moderate AHZ
AHZ Erosion Setback
Elevation
difference
(feet)
-0 to -0.5
-0.51 to -1
-1.01 to -2
-2.01 to -3
-3.01 to -4
-4.01 to -5
-5.01+
!(
5 | 6
7
SE RENTON-MAPLE
VALLEY RD
Cedar River Channel Migration Study - April 2015
Cedar River
Map 5. Avulsion Hazard Zone (AHZ)
Document Path: \\kc.kingcounty.lcl\dnrp\WLRD\RFMS\FLOOD\Flood Drive Files\Cedar-Samm\FLD202 Cedar CMZ Study\Final_to_DPER\Maps\Map5_Cedar_AHZ_tiled.mxd
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0 1,000500
Feet
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The information included on this map has been compiled by King County staff
from a variety of sources and is subject to change without notice.
King County makes no representations or warranties, express or implied, as to
accuracy, completeness, timeliness, or rights to the use of such information.
This document is not intended for use as a survey product. King County shall not
be liable for any general, special, indirect, incidental, or consequential damages
including, but not limited to, lost revenues or lost profits resulting from the use or
misuse of the information contained on this map.
Any sale of this map or information on this map is prohibited except by written
permission of King County.
APRIL 2015
!(!(!(1 | 20
2
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SGRADYWAYS2NDSTM A P L E VA L L E Y H W Y
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Cedar River
Legend
!(River Mile
Valley Wall
Reach Boundaries
City Boundaries
Levees and
Revetments
Unconstrained CMZ
Boundary
Historical Migration
Zone Boundary
2011 Active Channel
Severe Avulsion
Hazard Zone (AHZ)
Moderate AHZ
AHZ / Erosion Setback
Erosion Hazard Area /
Geotechnical Setback
Streets
Panel 1 of 8
Map 6. Unconstrained Channel
Migration Zone (CMZ)
Cedar River Channel Migration Study - April 2015
The information included on this map has been compiled by
King County staff from a variety of sources and is subject to
change without notice.
King County makes no representations or warranties,
express or implied, as to accuracy, completeness,
timeliness, or rights to the use of such information.
This document is not intended for use as a survey product.
King County shall not be liable for any general, special,
indirect, incidental, or consequential damages including, but
not limited to, lost revenues or lost profits resulting from the
use or misuse of the information contained on this map.
Any sale of this map or information on this map is prohibited
except by written permission of King County.
APRIL 2015
!(!(
!(
1 | 2 2 | 3
3 | 4
2 3
4 144THAVESEMAI
NAVESUNIONAVENEPUGETDRSEI-405FWYNE3RDST
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Cedar River
Legend
!(River Mile
Valley Wall
Reach Boundaries
City Boundaries
Levees and
Revetments
Unconstrained CMZ
Boundary
Historical Migration
Zone Boundary
2011 Active Channel
Severe Avulsion
Hazard Zone (AHZ)
Moderate AHZ
AHZ / Erosion Setback
Erosion Hazard Area /
Geotechnical Setback
Streets
Panel 2 of 8
Map 6. Unconstrained Channel
Migration Zone (CMZ)
Cedar River Channel Migration Study - April 2015
The information included on this map has been compiled by
King County staff from a variety of sources and is subject to
change without notice.
King County makes no representations or warranties,
express or implied, as to accuracy, completeness,
timeliness, or rights to the use of such information.
This document is not intended for use as a survey product.
King County shall not be liable for any general, special,
indirect, incidental, or consequential damages including, but
not limited to, lost revenues or lost profits resulting from the
use or misuse of the information contained on this map.
Any sale of this map or information on this map is prohibited
except by written permission of King County.
APRIL 2015
!(
!(
!(
5 | 6
3 | 4
4 | 5
5
7
6144THAVESE
SE FAIRWOOD BLVD
SE 144TH ST154THAVESESE142NDST156THAVESESE141STST 177THAVESE140THAVESESERENTON-MAPLEVALLEYRD 169THAVESESE142NDPL1
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King County
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Cedar River
Legend
!(River Mile
Valley Wall
Reach Boundaries
City Boundaries
Levees and
Revetments
Unconstrained CMZ
Boundary
Historical Migration
Zone Boundary
2011 Active Channel
Severe Avulsion
Hazard Zone (AHZ)
Moderate AHZ
AHZ / Erosion Setback
Erosion Hazard Area /
Geotechnical Setback
Streets
Panel 3 of 8
Map 6. Unconstrained Channel
Migration Zone (CMZ)
Cedar River Channel Migration Study - April 2015
The information included on this map has been compiled by
King County staff from a variety of sources and is subject to
change without notice.
King County makes no representations or warranties,
express or implied, as to accuracy, completeness,
timeliness, or rights to the use of such information.
This document is not intended for use as a survey product.
King County shall not be liable for any general, special,
indirect, incidental, or consequential damages including, but
not limited to, lost revenues or lost profits resulting from the
use or misuse of the information contained on this map.
Any sale of this map or information on this map is prohibited
except by written permission of King County.
APRIL 2015
!(!(!(!(8
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5 | 67 | 8
10
7
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7
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Cedar River
Legend
!(River Mile
Valley Wall
Reach Boundaries
City Boundaries
Levees and
Revetments
Unconstrained CMZ
Boundary
Historical Migration
Zone Boundary
2011 Active Channel
Severe Avulsion
Hazard Zone (AHZ)
Moderate AHZ
AHZ / Erosion Setback
Erosion Hazard Area /
Geotechnical Setback
Streets
Panel 4 of 8
Map 6. Unconstrained Channel
Migration Zone (CMZ)
Cedar River Channel Migration Study - April 2015
The information included on this map has been compiled by
King County staff from a variety of sources and is subject to
change without notice.
King County makes no representations or warranties,
express or implied, as to accuracy, completeness,
timeliness, or rights to the use of such information.
This document is not intended for use as a survey product.
King County shall not be liable for any general, special,
indirect, incidental, or consequential damages including, but
not limited to, lost revenues or lost profits resulting from the
use or misuse of the information contained on this map.
Any sale of this map or information on this map is prohibited
except by written permission of King County.
APRIL 2015
!(!(!(11 | 12
10 | 117 | 8
9 | 10
8 | 9
10
12
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Document Path: \\kc.kingcounty.lcl\dnrp\WLRD\RFMS\FLOOD\Flood Drive Files\Cedar-Samm\FLD202 Cedar CMZ Study\Final_to_DPER\Maps\Map6_Cedar_unconstrained_CMZ.mxd
Cedar River
Legend
!(River Mile
Valley Wall
Reach Boundaries
City Boundaries
Levees and
Revetments
Unconstrained CMZ
Boundary
Historical Migration
Zone Boundary
2011 Active Channel
Severe Avulsion
Hazard Zone (AHZ)
Moderate AHZ
AHZ / Erosion Setback
Erosion Hazard Area /
Geotechnical Setback
Streets
Panel 5 of 8
Map 6. Unconstrained Channel
Migration Zone (CMZ)
Cedar River Channel Migration Study - April 2015
The information included on this map has been compiled by
King County staff from a variety of sources and is subject to
change without notice.
King County makes no representations or warranties,
express or implied, as to accuracy, completeness,
timeliness, or rights to the use of such information.
This document is not intended for use as a survey product.
King County shall not be liable for any general, special,
indirect, incidental, or consequential damages including, but
not limited to, lost revenues or lost profits resulting from the
use or misuse of the information contained on this map.
Any sale of this map or information on this map is prohibited
except by written permission of King County.
APRIL 2015
!(!(!(13 | 1412 | 1314
|
1
5
11 | 12
15
14
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Document Path: \\kc.kingcounty.lcl\dnrp\WLRD\RFMS\FLOOD\Flood Drive Files\Cedar-Samm\FLD202 Cedar CMZ Study\Final_to_DPER\Maps\Map6_Cedar_unconstrained_CMZ.mxd
Cedar River
Legend
!(River Mile
Valley Wall
Reach Boundaries
City Boundaries
Levees and
Revetments
Unconstrained CMZ
Boundary
Historical Migration
Zone Boundary
2011 Active Channel
Severe Avulsion
Hazard Zone (AHZ)
Moderate AHZ
AHZ / Erosion Setback
Erosion Hazard Area /
Geotechnical Setback
Streets
Panel 6 of 8
Map 6. Unconstrained Channel
Migration Zone (CMZ)
Cedar River Channel Migration Study - April 2015
The information included on this map has been compiled by
King County staff from a variety of sources and is subject to
change without notice.
King County makes no representations or warranties,
express or implied, as to accuracy, completeness,
timeliness, or rights to the use of such information.
This document is not intended for use as a survey product.
King County shall not be liable for any general, special,
indirect, incidental, or consequential damages including, but
not limited to, lost revenues or lost profits resulting from the
use or misuse of the information contained on this map.
Any sale of this map or information on this map is prohibited
except by written permission of King County.
APRIL 2015
!(
!(
!(
!(
!(
18 | 1915
|
1617 | 1816 | 1714 | 1519
18
16
20
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Cedar River
Legend
!(River Mile
Valley Wall
Reach Boundaries
City Boundaries
Levees and
Revetments
Unconstrained CMZ
Boundary
Historical Migration
Zone Boundary
2011 Active Channel
Severe Avulsion
Hazard Zone (AHZ)
Moderate AHZ
AHZ / Erosion Setback
Erosion Hazard Area /
Geotechnical Setback
Streets
Panel 7 of 8
Map 6. Unconstrained Channel
Migration Zone (CMZ)
Cedar River Channel Migration Study - April 2015
The information included on this map has been compiled by
King County staff from a variety of sources and is subject to
change without notice.
King County makes no representations or warranties,
express or implied, as to accuracy, completeness,
timeliness, or rights to the use of such information.
This document is not intended for use as a survey product.
King County shall not be liable for any general, special,
indirect, incidental, or consequential damages including, but
not limited to, lost revenues or lost profits resulting from the
use or misuse of the information contained on this map.
Any sale of this map or information on this map is prohibited
except by written permission of King County.
APRIL 2015
!(
!(
!(
20
1 8 | 19 19 | 2022
21
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Cedar River
Legend
!(River Mile
Valley Wall
Reach Boundaries
City Boundaries
Levees and
Revetments
Unconstrained CMZ
Boundary
Historical Migration
Zone Boundary
2011 Active Channel
Severe Avulsion
Hazard Zone (AHZ)
Moderate AHZ
AHZ / Erosion Setback
Erosion Hazard Area /
Geotechnical Setback
Streets
Panel 8 of 8
Map 6. Unconstrained Channel
Migration Zone (CMZ)
Cedar River Channel Migration Study - April 2015
The information included on this map has been compiled by
King County staff from a variety of sources and is subject to
change without notice.
King County makes no representations or warranties,
express or implied, as to accuracy, completeness,
timeliness, or rights to the use of such information.
This document is not intended for use as a survey product.
King County shall not be liable for any general, special,
indirect, incidental, or consequential damages including, but
not limited to, lost revenues or lost profits resulting from the
use or misuse of the information contained on this map.
Any sale of this map or information on this map is prohibited
except by written permission of King County.
APRIL 2015
!(!(!(1 | 20
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Document Path: \\kc.kingcounty.lcl\dnrp\WLRD\RFMS\FLOOD\Flood Drive Files\Cedar-Samm\FLD202 Cedar CMZ Study\Final_to_DPER\Maps\Map7_Cedar_CMZ.mxd
Cedar River
Legend
!(River Mile
City Boundaries
Reach Boundaries
Levees and Revetments
Valley Wall
Streets
Parcels
2011 Active Channel
CMZ Boundary
Severe Hazard Area
Moderate Hazard Area
Panel 1 of 8
Map 7. Cedar River Channel
Migration Zone (CMZ)
APRIL 2015
The information included on this map has been compiled
by King County staff from a variety of sources and is
subject to change without notice.
King County makes no representations or warranties,
express or implied, as to accuracy, completeness,
timeliness, or rights to the use of such information.
This document is not intended for use as a survey product.
King County shall not be liable for any general, special,
indirect, incidental, or consequential damages including,
but not limited to, lost revenues or lost profits resulting
from the use or misuse of the information contained on this
map.
Any sale of this map or information on this map is
prohibited except by written permission of King County.
Cedar River Channel Migration Study - April 2015
!(!(
!(
1 | 2 2 | 3
3 | 4
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4
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Document Path: \\kc.kingcounty.lcl\dnrp\WLRD\RFMS\FLOOD\Flood Drive Files\Cedar-Samm\FLD202 Cedar CMZ Study\Final_to_DPER\Maps\Map7_Cedar_CMZ.mxd
Cedar River
Legend
!(River Mile
City Boundaries
Reach Boundaries
Levees and Revetments
Valley Wall
Streets
Parcels
2011 Active Channel
CMZ Boundary
Severe Hazard Area
Moderate Hazard Area
Panel 2 of 8
Map 7. Cedar River Channel
Migration Zone (CMZ)
APRIL 2015
The information included on this map has been compiled
by King County staff from a variety of sources and is
subject to change without notice.
King County makes no representations or warranties,
express or implied, as to accuracy, completeness,
timeliness, or rights to the use of such information.
This document is not intended for use as a survey product.
King County shall not be liable for any general, special,
indirect, incidental, or consequential damages including,
but not limited to, lost revenues or lost profits resulting
from the use or misuse of the information contained on this
map.
Any sale of this map or information on this map is
prohibited except by written permission of King County.
Cedar River Channel Migration Study - April 2015
!(
!(
!(
5 | 6
3 | 4
4 | 5
5
7
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Document Path: \\kc.kingcounty.lcl\dnrp\WLRD\RFMS\FLOOD\Flood Drive Files\Cedar-Samm\FLD202 Cedar CMZ Study\Final_to_DPER\Maps\Map7_Cedar_CMZ.mxd
Cedar River
Legend
!(River Mile
City Boundaries
Reach Boundaries
Levees and Revetments
Valley Wall
Streets
Parcels
2011 Active Channel
CMZ Boundary
Severe Hazard Area
Moderate Hazard Area
Panel 3 of 8
Map 7. Cedar River Channel
Migration Zone (CMZ)
APRIL 2015
The information included on this map has been compiled
by King County staff from a variety of sources and is
subject to change without notice.
King County makes no representations or warranties,
express or implied, as to accuracy, completeness,
timeliness, or rights to the use of such information.
This document is not intended for use as a survey product.
King County shall not be liable for any general, special,
indirect, incidental, or consequential damages including,
but not limited to, lost revenues or lost profits resulting
from the use or misuse of the information contained on this
map.
Any sale of this map or information on this map is
prohibited except by written permission of King County.
Cedar River Channel Migration Study - April 2015
!(!(!(!(8
|6 | 7
5 | 67 | 8
10
7
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Document Path: \\kc.kingcounty.lcl\dnrp\WLRD\RFMS\FLOOD\Flood Drive Files\Cedar-Samm\FLD202 Cedar CMZ Study\Final_to_DPER\Maps\Map7_Cedar_CMZ.mxd
Cedar River
Legend
!(River Mile
City Boundaries
Reach Boundaries
Levees and Revetments
Valley Wall
Streets
Parcels
2011 Active Channel
CMZ Boundary
Severe Hazard Area
Moderate Hazard Area
Panel 4 of 8
Map 7. Cedar River Channel
Migration Zone (CMZ)
APRIL 2015
The information included on this map has been compiled
by King County staff from a variety of sources and is
subject to change without notice.
King County makes no representations or warranties,
express or implied, as to accuracy, completeness,
timeliness, or rights to the use of such information.
This document is not intended for use as a survey product.
King County shall not be liable for any general, special,
indirect, incidental, or consequential damages including,
but not limited to, lost revenues or lost profits resulting
from the use or misuse of the information contained on this
map.
Any sale of this map or information on this map is
prohibited except by written permission of King County.
Cedar River Channel Migration Study - April 2015
!(!(!(11 | 12
10 | 117 | 8
9 | 10
8 | 9
10
12
11
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RENTON-MAPLE VALLEY RD SE
S E L A K E F R A N C I S R D 0 1,000 2,000500
Feet
Document Path: \\kc.kingcounty.lcl\dnrp\WLRD\RFMS\FLOOD\Flood Drive Files\Cedar-Samm\FLD202 Cedar CMZ Study\Final_to_DPER\Maps\Map7_Cedar_CMZ.mxd
Cedar River
Legend
!(River Mile
City Boundaries
Reach Boundaries
Levees and Revetments
Valley Wall
Streets
Parcels
2011 Active Channel
CMZ Boundary
Severe Hazard Area
Moderate Hazard Area
Panel 5 of 8
Map 7. Cedar River Channel
Migration Zone (CMZ)
APRIL 2015
The information included on this map has been compiled
by King County staff from a variety of sources and is
subject to change without notice.
King County makes no representations or warranties,
express or implied, as to accuracy, completeness,
timeliness, or rights to the use of such information.
This document is not intended for use as a survey product.
King County shall not be liable for any general, special,
indirect, incidental, or consequential damages including,
but not limited to, lost revenues or lost profits resulting
from the use or misuse of the information contained on this
map.
Any sale of this map or information on this map is
prohibited except by written permission of King County.
Cedar River Channel Migration Study - April 2015
!(!(!(13 | 1412 | 1314
|
1
5
11 | 12
15
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Document Path: \\kc.kingcounty.lcl\dnrp\WLRD\RFMS\FLOOD\Flood Drive Files\Cedar-Samm\FLD202 Cedar CMZ Study\Final_to_DPER\Maps\Map7_Cedar_CMZ.mxd
Cedar River
Legend
!(River Mile
City Boundaries
Reach Boundaries
Levees and Revetments
Valley Wall
Streets
Parcels
2011 Active Channel
CMZ Boundary
Severe Hazard Area
Moderate Hazard Area
Panel 6 of 8
Map 7. Cedar River Channel
Migration Zone (CMZ)
APRIL 2015
The information included on this map has been compiled
by King County staff from a variety of sources and is
subject to change without notice.
King County makes no representations or warranties,
express or implied, as to accuracy, completeness,
timeliness, or rights to the use of such information.
This document is not intended for use as a survey product.
King County shall not be liable for any general, special,
indirect, incidental, or consequential damages including,
but not limited to, lost revenues or lost profits resulting
from the use or misuse of the information contained on this
map.
Any sale of this map or information on this map is
prohibited except by written permission of King County.
Cedar River Channel Migration Study - April 2015
!(
!(
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18 | 1915
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1617 | 1816 | 1714 | 1519
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Document Path: \\kc.kingcounty.lcl\dnrp\WLRD\RFMS\FLOOD\Flood Drive Files\Cedar-Samm\FLD202 Cedar CMZ Study\Final_to_DPER\Maps\Map7_Cedar_CMZ.mxd
Cedar River
Legend
!(River Mile
City Boundaries
Reach Boundaries
Levees and Revetments
Valley Wall
Streets
Parcels
2011 Active Channel
CMZ Boundary
Severe Hazard Area
Moderate Hazard Area
Panel 7 of 8
Map 7. Cedar River Channel
Migration Zone (CMZ)
APRIL 2015
The information included on this map has been compiled
by King County staff from a variety of sources and is
subject to change without notice.
King County makes no representations or warranties,
express or implied, as to accuracy, completeness,
timeliness, or rights to the use of such information.
This document is not intended for use as a survey product.
King County shall not be liable for any general, special,
indirect, incidental, or consequential damages including,
but not limited to, lost revenues or lost profits resulting
from the use or misuse of the information contained on this
map.
Any sale of this map or information on this map is
prohibited except by written permission of King County.
Cedar River Channel Migration Study - April 2015
!(
!(
!(
20
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21
20
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Document Path: \\kc.kingcounty.lcl\dnrp\WLRD\RFMS\FLOOD\Flood Drive Files\Cedar-Samm\FLD202 Cedar CMZ Study\Final_to_DPER\Maps\Map7_Cedar_CMZ.mxd
Cedar River
Legend
!(River Mile
City Boundaries
Reach Boundaries
Levees and Revetments
Valley Wall
Streets
Parcels
2011 Active Channel
CMZ Boundary
Severe Hazard Area
Moderate Hazard Area
Panel 8 of 8
Map 7. Cedar River Channel
Migration Zone (CMZ)
APRIL 2015
The information included on this map has been compiled
by King County staff from a variety of sources and is
subject to change without notice.
King County makes no representations or warranties,
express or implied, as to accuracy, completeness,
timeliness, or rights to the use of such information.
This document is not intended for use as a survey product.
King County shall not be liable for any general, special,
indirect, incidental, or consequential damages including,
but not limited to, lost revenues or lost profits resulting
from the use or misuse of the information contained on this
map.
Any sale of this map or information on this map is
prohibited except by written permission of King County.
Cedar River Channel Migration Study - April 2015