HomeMy WebLinkAboutStorage One TIR TECHNICAL INFORMATION REPORT Storage One Renton, Washington Our Job. No. 12740
12740.008.doc
TABLE OF CONTENTS
PAGE NUMBERS
1.0 PROJECT OVERVIEW ............................................................................................................................. 1
Figure 1 – Technical Information Report (TIR) Worksheet ....................................................................... 2
Figure 2 – Vicinity Map ............................................................................................................................. 8
Figure 3 – Drainage Basins, Subbasins, and Site Characteristics .......................................................... 10
Figure 4 – Soils Map ............................................................................................................................... 13
2.0 CONDITIONS AND REQUIREMENTS SUMMARY................................................................................ 18
2.1 Analysis of the Eight Core Requirements ........................................................................................ 18
2.2 Analysis of the Five Special Requirements .............................................................................. 19
3.0 OFF-SITE ANALYSIS .................................................................................................................. 21
4.0 FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN ............................. 172
A. Existing Site Hydrology .................................................................................................................. 172
A-1. Predeveloped Hourly Time Step Modeling Input
A-2. Predeveloped Hourly Time Step Modeling Output
B. Developed Site Hydrology .................................................................................................... 172
B-2. Developed Hourly Time Step Modeling Input
B-3. Developed Hourly Time Step Modeling Output
B-4. Bypass Input
B-5. Bypass Output
B-6. Discharge From Pond
B-7. Discharge From Site
C. Performance Standards ................................................................................................................. 173
D. Flow Control System ..................................................................................................................... 173
D-1. Flow Control BMP Selection & Design
D-2. Flow Control Facility Design Output
D-2.1 Raingarden
D-2.2 Modular Grid Pavement
D-2.3 Permeable Pavement
E. Water Quality System .................................................................................................................... 174
5.0 CONVEYANCE SYSTEM ANALYSIS AND DESIGN ........................................................................... 199
6.0 SPECIAL REPORTS AND STUDIES ................................................................................................... 209
7.0 OTHER PERMITS ................................................................................................................................ 235
8.0 CSWPPP ANALYSIS AND DESIGN .................................................................................................... 237
9.0 BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT ...................... 239
10.0 OPERATION AND MAINTENANCE MANUAL ..................................................................................... 250
12740.008.doc
1.0 PROJECT OVERVIEW
The proposed Storage One on 4th Expansion project is a 1.83 acre site located within a portion of
the Northwest quarter of Section 15, Township 23 North, Range 5 East, Willamette Meridian, King
County, Washington. More specifically, the site is located approximately 500 feet east of NE 4th
Street and Duvall Avenue NE in Renton, Washington. The enclosed Figure 2 – Vicinity Map,
depicts the approximate location of the proposed site.
The site is currently partially developed. There is a concrete driveway and small gravel lot on
site. The remainder of the site is grass and trees. There is an isolated Class 3 Wetland (9,529
square feet) located on this project as well as a Class 4 Stream that runs along the east boundary
of the site. The existing topography tends to slope to the east side of the site to the existing
stream that runs south through the project. There are no existing buildings on the site.
The storm drainage facility is proposed to be located near the southwest corner of the project site
and discharge to the existing stream at the southeast corner. The flow control calculations are for
the development and do not include the stream or buffer. The existing row is currently paved and
runoff is collected in existing catch basins along the project frontage.
The northern boundary of the project site is formed by NE 4th Street. Existing commercial
developments are to the west and residential developments are to the east and south.
The proposal for this development is to construct an expansion of the adjacent Storage One
facility. This will include new driveways and parking, a new storage building and a new
retail/office building with restrooms. In addition, public road improvements will be constructed
along NE 4th Street. Elevations on the site are 398 for the majority of the site, down to 395 at the
west and east boundaries of the project site.
Infiltration is not feasible for this site as the on-site soils do not percolate well enough.
A Flow Control BMP is required for this site. This project is a non-subdivision project on an
individual lot that meets the requirements for a large lot, high impervious BMP. An area of the
impervious site equal to 40 percent of the site impervious area will be treated with a flow control
BMP. An on-site rain garden and modular grid pavement will be used before runoff is sent to the
detention pond and water quality system.
The site has been designed according to the 2010 City of Renton Amendments to the 2009 King
County Surface Water Design Manual. The Flow Control Duration Standard Matching Forested
Site Conditions performance standard has been applied to this site. Enhanced Basic Water
Quality is also required as this is a commercial site.
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Soil Map—King County Area, Washington
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/9/2014
Page 1 of 35259690525970052597105259720525973052597405259750525976052597705259780525979052596905259700525971052597205259730525974052597505259760525977052597805259790563620563630563640563650563660563670563680563690563700563710563720563730563740563750563760563770
563620 563630 563640 563650 563660 563670 563680 563690 563700 563710 563720 563730 563740 563750 563760 563770 563780
47° 29' 18'' N 122° 9' 19'' W47° 29' 18'' N122° 9' 12'' W47° 29' 15'' N
122° 9' 19'' W47° 29' 15'' N
122° 9' 12'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 10N WGS84
0 35 70 140 210Feet
0 10 20 40 60Meters
Map Scale: 1:756 if printed on A landscape (11" x 8.5") sheet.14
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Map Unit Polygons
Soil Map Unit Lines
Soil Map Unit Points
Special Point Features
Blowout
Borrow Pit
Clay Spot
Closed Depression
Gravel Pit
Gravelly Spot
Landfill
Lava Flow
Marsh or swamp
Mine or Quarry
Miscellaneous Water
Perennial Water
Rock Outcrop
Saline Spot
Sandy Spot
Severely Eroded Spot
Sinkhole
Slide or Slip
Sodic Spot
Spoil Area
Stony Spot
Very Stony Spot
Wet Spot
Other
Special Line Features
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at 1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil line
placement. The maps do not show the small areas of contrasting
soils that could have been shown at a more detailed scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more accurate
calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as of
the version date(s) listed below.
Soil Survey Area: King County Area, Washington
Survey Area Data: Version 10, Sep 30, 2014
Soil map units are labeled (as space allows) for map scales 1:50,000
or larger.
Date(s) aerial images were photographed: Jul 8, 2014—Jul 15,
2014
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor shifting
of map unit boundaries may be evident.
Soil Map—King County Area, Washington
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/9/2014
Page 2 of 315
Map Unit Legend
King County Area, Washington (WA633)
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
AgC Alderwood gravelly sandy loam,
8 to 15 percent slopes
0.0 0.1%
EvB Everett gravelly sandy loam, 0
to 5 percent slopes
1.8 99.9%
Totals for Area of Interest 1.8 100.0%
Soil Map—King County Area, Washington
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/9/2014
Page 3 of 3
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12740.008.doc
2.0 CONDITIONS AND REQUIREMENTS SUMMARY
2.1 Analysis of the Eight Core Requirements
Core Requirement No. 1: Discharge at the Natural Location.
Response: This project site will discharge to the existing Class IV stream, the same as
current conditions.
Core Requirement No. 2: Off-Site Analysis.
Response: This project has prepared an off-site analysis that is located in Section 3.0 of
this Technical Information Report. Please refer to that document for the off-site analysis.
Core Requirement No. 3: Flow Control.
Response: The project is located within the Flow Control Duration Standard - Matching
Forested flow control area as depicted on the City of Renton Flow Control Applications
Map and this is the standard applied to this project. The difference between existing and
developed 100-yr peak flows is greater than 0.1-cfs, therefore a flow control facility will be
required. This project will provide flow control in the form of a detention pond located in
the southwest corner of the project site discharging to the same location as it does under
existing conditions. A Flow Control BMP is also required. A rain garden is proposed in
the southeast portion of the site. The emergency access road will be comprised of a
grassed modular grid pavement. The proposed rain garden and modular grid pavement
satisfy the requirement for flow control BMP.
Core Requirement No. 4: Conveyance System.
Response: The conveyance system for this project site was sized according to the 2010
City of Renton Amendments to the 2009 King County, Washington Surface Water Design
Manual (KCSWDM). Since the project site is less than 10 acres in size, the pipe
conveyance system was sized based on the Rational method utilizing an initial time of
concentration of 6.3 minutes and a Manning's "n" value of 0.014. The 100-year event
was analyzed. A backwater calculation has been completed and shows that 0.19 feet of
freeboard is provided in the 100-yr storm event. The requirement is that a new pipe
conveyance system be designed to convey the 25-year peak flow at a minimum,
therefore this requirement is satisfied as this system is capable of conveying the 100-yr
event.
Core Requirement No. 5: Temporary Erosion and Sediment Control.
Response: This project site will follow the erosion and sediment control measures as
delineated in City of Renton Core Requirement 5, section 8.0 of this report and the
Demolition and TESC Plan included in the construction plans. Clearing limits will be
specified, cover measures will be instituted, perimeter protection will be installed in the
form of silt fences, a rock construction entrance will be installed, and the streets will be
swept clean of sediment after construction at the end of each day.
Core Requirement No. 6: Maintenance and Operations.
Response: This project will concur with all maintenance and operations requirements as
delineated in the 2009 KCSWDM for projects of this nature.
Core Requirement No. 7: Financial Guarantees and Liability.
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12740.008.doc
Response: This project will concur with all financial guarantees and liability
requirements of the 2009 KCSWDM as delineated for projects of this nature.
Core Requirement No. 8: Water Quality.
Response: This project will create/add more than 5,000 square feet of pollution
generating impervious surface and therefore will require water quality treatment. The
Water Quality Menu followed for this project site requires that the Enhanced Basic Water
Quality Menu be followed for this development due to its commercial nature. This project
is proposing the use of a modular wetland which has DOE GULD approval for enhanced
treatment. An adjustment has been approved by the City for the use of a Modular
Wetland and a copy of the approval letter is included in Section 4.E. This system uses
media to treat storm water runoff. Per section 6.2.1 of the KCSWDM this facility is
designed to treat the full 2-year release rate from the detention facility. There will also be
two flow control BMPs, a rain-garden in the southeast corner of the site to further treat
roof runoff, as well as an emergency access road paved with a grassed modular grid
pavement.
2.2 Analysis of the Five Special Requirements
Special Requirement No. 1: Other Adopted Area-Specific Requirements.
Response: To the best of our knowledge, the site is not located in an Other Adopted
Area-Specific Requirement area; therefore, Special Requirement No. 1 does not apply.
Special Requirement No. 2: Flood Hazard Area Delineation.
Response: This project does not contain, nor is it adjacent to a flood hazard area for a
river, stream, lake, wetland, closed depression, marine shoreline, or a King County
mapped channel migration zone. Therefore, the requirements of this Special
Requirement do not apply.
Special Requirement No. 3: Flood Protection Facilities.
Response: This proposed project will not rely on an existing flood protection facility, nor
does it propose to modify or construct a new flood protection facility. Therefore, the
requirements of this Special Requirement do not apply.
Special Requirement No. 4: Source Control.
Response: This project is a commercial site development; therefore, source control is
required. Sources controls on this project include covering dumpster areas.
Special Requirement No. 5: Oil Control.
Response: This site does not qualify as a high-use site. Therefore, the requirements of
this Special Requirement do not apply.
Special Requirement No. 6: Aquifer Protection Area.
Response: This site is not located in an aquifer protection area. The onsite soils are not
conducive to infiltration. The only runoff to the proposed rain garden is from the building
roof and emergency access road, both of which are non-pollution generating impervious
surface.
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12740.008.doc
3.0 OFF-SITE ANALYSIS
Runoff leaves the site at the southeast corner of the property discharging east to Maplewood
Creek. Maplewood Creek continues south and eventually joins another branch of Maplewood
Creek before it flows through the Maplewood Golf Course and discharges to the Cedar River.
A Level 1 Off-Site Drainage Analysis has been prepared for this project site. That document is
attached herewith in its entirety. This document should meet all of the requirements of the City of
Renton for off-site analysis for this development.
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15432.003.doc
TABLE OF CONTENTS
TASK 1 STUDY AREA DEFINITION AND MAPS
EXHIBIT A Vicinity Map
EXHIBIT B Downstream Drainage Map
EXHIBIT C Upstream Basin Map
TASK 2 RESOURCE REVIEW
EXHIBIT D FEMA Map
EXHIBIT E Sensitive Areas Map
EXHIBIT F SCS Soils Map
EXHIBIT G Assessor’s Map
EXHIBIT H Wetland Inventory Map
EXHIBIT I Basin Reconnaissance Summary Report
TASK 3 FIELD INSPECTION
EXHIBIT J Off-Site Analysis Drainage System Table
3.1 Conveyance System Nuisance Problems (Type 1)
3.2 Severe Erosion Problems (Type 2)
3.3 Severe Flooding Problems (Type 3)
TASK 4 DRAINAGE SYSTEM DESCRIPTION AND PROBLEM DESCRIPTIONS
EXHIBIT K Drainage Complaints
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15432.005.doc
TASK 1 STUDY AREA DEFINITION AND MAPS
The proposed Storage One project is a 1.83 acre site located within a portion of the Northwest quarter of
Section 15, Township 23 North, Range 5 East, Willamette Meridian, King County, Washington. More
specifically, the site is located approximately 500 feet east of NE 4th Street and Duvall Avenue NE in
Renton, Washington. The enclosed Exhibit A – Vicinity Map, depicts the approximate location of the
proposed site.
The site is currently partially developed. There is a concrete driveway and small gravel lot on site. The
remainder of the site is grass and trees. The existing topography tends to slope to the east side of the
site. There are no existing buildings on the site.
The storm drainage facility is proposed to be located in near the southwest corner of the project site such
that the site will discharge in the same location it does under existing conditions. There is an isolated
Class 3 Wetland (9,529 square feet) located on this project as well as a Class 4 Stream that runs along
the east boundary of the site.
The northern boundary of the project site is formed by NE 4th Street. Existing commercial developments
are to west and residential developments are to the east and south.
The proposal for this development is to construct an expansion of the adjacent Storage One facility. This
will include new access drives and parking, a new storage building and a new retail/office building with
restrooms. In addition, public road improvements will be constructed along 4th Street. Elevations on the
site are 398 for the majority of the site, down to 395 at the west and east boundaries of the project site.
Infiltration is not feasible for this site as the on-site soils do not percolate well enough.
A Flow Control BMP is required for this site. This project is a non-subdivision project on an individual lot
that meets the requirements for a large lot, high impervious BMP. An area of the impervious site equal to
40 percent of the impervious site area will be directed to an on-site rain garden or will be constructed on
Grassed Modular Grid Pavement before being sent to the detention pond.
UPSTREAM DRAINAGE ANALYSIS
Based on review of the project survey and our site visit, there is no offsite runoff contributing to the project
site. The site has been filled and raised relative to the surrounding properties.
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15432.005.doc
TASK 2 RESOURCE REVIEW
· Adopted Basin Plans: The site is part of the Lower Cedar River drainage basin, and is in the
Maplewood Sub Basin.
· Finalized Drainage Studies: This is not applicable.
· Basin Reconnaissance Summary Report: Once again, the site is located in the Lower Cedar
River drainage basin and is in the Maplewood Sub Basin.
· Critical Drainage Area Maps: According to the city of Renton, Enhanced Basic Water Quality
treatment is required. Also, Level 2 (Duration standard) flow control is required for this site.
· Floodplain and Floodway FEMA Maps: Please the enclosed Exhibit D – FEMA Map utilized for
this analysis. Panel No. 982 of 1,725, Map No. 53033C0982 F, revised May 16, 1995, indicates
that the proposed project site does not lie within a floodplain or floodway of a stream.
· Other Off-Site Analysis Reports: A review of Exhibit I – Basin Reconnaissance Summary Report
and the site investigation work conducted in the preparation of this Level 1 Drainage Analysis.
The U.S. Department of Agriculture Soils Conservation Service (SCS) soils map is also provided
(see Exhibit F – SCS Soils Map).
· Sensitive Areas Folios: Based on a review of the sensitive areas as shown on the City of Renton
GIS maps, it was found that there is a wetland on subject site. A Wetland Delineation Report was
done for the site there is a 9,529ft Category III wetland on site as well as a Category II wetland by
the south boundary. The Category III wetland is believed to be the result of filling the site and as
such should be exempt from regulation. The Category II wetland shall require a 25-foot buffer.
There is also a surveyed Class 4 stream which runs along the east property boundary that shall
require a 35’ buffer. There are no landslide, flood, seismic or coal mine hazards, etc., associated
with this project site.
· Road Drainage Problems: This is not applicable.
· United States Department of Agriculture King County Soils Survey: Based on our review of the
soils map for this area, the entire site is 95% EvB (Everett gravelly sandy loam) and 5% AgC
(Alderwood gravelly sandy loam).
· Wetland Inventory Map: There is a Category III wetland on site as well as a Category II wetland.
The Category III wetland is due to prior filling of the property and as such should be exempt from
regulation requirements. The Category II wetland shall require a 25-foot buffer.
· Migrating River Studies: This is not applicable.
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2,257
188
WGS_1984_Web_Mercator_Auxiliary_Sphere
City of Renton Print map Storage One
This map is a user generated static output from an Internet mapping site and
is for reference only. Data layers that appear on this map may or may not be
accurate, current, or otherwise reliable.
THIS MAP IS NOT TO BE USED FOR NAVIGATION
Notes
None
Legend
128 0 64 128 Feet
Information Technology - GIS
RentonMapSupport@Rentonwa.gov
12/09/2014
City and County Boundary
Other
City of Renton
Addresses
Parcels
1st Floor
1st Floor
2nd Floor
1st Floor
Other Buildings
Buildings
Slope City of Renton
>15% & <=25%
>25% & <=40% (Sensitive)
>40% & <=90% (Protected)
>90% (Protected)
Environment Designations
Natural
Shoreline High Intensity
Shoreline Isolated High Intensity
Shoreline Residential
Urban Conservancy
Jurisdictions36
37
Soil Map—King County Area, Washington
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/9/2014
Page 1 of 35259690525970052597105259720525973052597405259750525976052597705259780525979052596905259700525971052597205259730525974052597505259760525977052597805259790563620563630563640563650563660563670563680563690563700563710563720563730563740563750563760563770
563620 563630 563640 563650 563660 563670 563680 563690 563700 563710 563720 563730 563740 563750 563760 563770 563780
47° 29' 18'' N 122° 9' 19'' W47° 29' 18'' N122° 9' 12'' W47° 29' 15'' N
122° 9' 19'' W47° 29' 15'' N
122° 9' 12'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 10N WGS84
0 35 70 140 210Feet
0 10 20 40 60Meters
Map Scale: 1:756 if printed on A landscape (11" x 8.5") sheet.38
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Map Unit Polygons
Soil Map Unit Lines
Soil Map Unit Points
Special Point Features
Blowout
Borrow Pit
Clay Spot
Closed Depression
Gravel Pit
Gravelly Spot
Landfill
Lava Flow
Marsh or swamp
Mine or Quarry
Miscellaneous Water
Perennial Water
Rock Outcrop
Saline Spot
Sandy Spot
Severely Eroded Spot
Sinkhole
Slide or Slip
Sodic Spot
Spoil Area
Stony Spot
Very Stony Spot
Wet Spot
Other
Special Line Features
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at 1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil line
placement. The maps do not show the small areas of contrasting
soils that could have been shown at a more detailed scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more accurate
calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as of
the version date(s) listed below.
Soil Survey Area: King County Area, Washington
Survey Area Data: Version 10, Sep 30, 2014
Soil map units are labeled (as space allows) for map scales 1:50,000
or larger.
Date(s) aerial images were photographed: Jul 8, 2014—Jul 15,
2014
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor shifting
of map unit boundaries may be evident.
Soil Map—King County Area, Washington
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/9/2014
Page 2 of 339
Map Unit Legend
King County Area, Washington (WA633)
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
AgC Alderwood gravelly sandy loam,
8 to 15 percent slopes
0.0 0.1%
EvB Everett gravelly sandy loam, 0
to 5 percent slopes
1.8 99.9%
Totals for Area of Interest 1.8 100.0%
Soil Map—King County Area, Washington
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
12/9/2014
Page 3 of 3
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2,257
188
WGS_1984_Web_Mercator_Auxiliary_Sphere
City of Renton Print map Storage One
This map is a user generated static output from an Internet mapping site and
is for reference only. Data layers that appear on this map may or may not be
accurate, current, or otherwise reliable.
THIS MAP IS NOT TO BE USED FOR NAVIGATION
Notes
None
Legend
128 0 64 128 Feet
Information Technology - GIS
RentonMapSupport@Rentonwa.gov
12/09/2014
City and County Boundary
Other
City of Renton
Addresses
Parcels
1st Floor
1st Floor
2nd Floor
1st Floor
Other Buildings
Buildings
Environment Designations
Natural
Shoreline High Intensity
Shoreline Isolated High Intensity
Shoreline Residential
Urban Conservancy
Jurisdictions
Streams (Classified)
1
2
3
4
Wetlands44
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15432.005.doc
TASK 3 FIELD INSPECTION
There were no problems observed during the resource review. Based on a review of the drainage
complaints of the downstream drainage course, there were a few minor drainage issues in the
Maplewood Creek drainage basin, downstream of the site.
3.1 Conveyance System Nuisance Problems (Type 1)
Conveyance system nuisance problems, in general, are defined as any existing or predicted
flooding or erosion that does not constitute a severe flooding or erosion problem. Conveyance
system nuisance problems are defined as flooding or erosion that results in the overflow of the
constructed conveyance system for runoff events less than or equal to a 10-year event.
Examples include inundation of a shoulder or lane of a roadway, overflows collecting in yards or
pastures, shallow flows across driveways, minor flooding in crawlspaces or unheated
garages/outbuildings and minor erosion.
Based on a review of the drainage complaints, there were complaints of localized flooding
approximately 1700 feet downstream of the site where Maplewood Creek crosses NE 2nd. The
localized flooding was due to plugged roadside culverts and the drainage ditch and fallen trees
blocking the drainage. Other localized flooding of backyards were due to a depression that has
since been corrected by the home builder. The Maplewood Creek Sedimentation Pond also has
heavy siltation but it is maintained annually as needed. These complaints all occurred prior to
2006 when this area was annexed to the City of Renton.
With the improvements of this project site, there is the potential that problems on the downstream
drainage course may be helped somewhat by providing onsite detention of storm water.
3.2 Severe Erosion Problems (Type 2)
Severe erosion problems are defined as downstream channels, ravines, or slopes with evidence
of or potential for erosion/incision, sufficient to pose a sedimentation hazard to downstream
conveyance systems or propose a landslide hazard by undercutting adjacent slopes. Severe
erosion problems do not include roadway or minor ditch erosion.
The site visit did not find erosion problems evident anywhere along the downstream drainage
course.
3.3 Severe Flooding Problems (Type 3)
Severe flooding problems can be caused by conveyance system overflows or the elevated water
surfaces of ponds, lakes, wetlands, or closed depressions. Severe flooding problems warrant
additional attention because they pose a significant threat either to health and safety or to public
or private property.
Neither the review of the drainage complaints nor the site visit noted any severe flooding
problems in the downstream drainage course. Portions of the downstream drainage course
investigated by the site visit and a review of the soils map indicates that the downstream drainage
course occurs through till type soils. The field reconnaissance for this off-site analysis drainage
report was conducted on the morning of September 19, 2012. The skies were clear and the
temperature on this day was approximately 65 degrees.
158
159
12740.005.doc OFF-SITE ANALYSIS DRAINAGE SYSTEM TABLE Surface Water Design Manual, Core Requirement #2 Basin: Cedar River Subbasin Name: Maplewood Creek Subbasin Number: Symbol Drainage Component Type, Name, and Size Drainage Component Description Slope Distance from Site Discharge Existing Problems Potential Problems Observations of Field Inspector, Resource Reviewer, or Resident See Map Type: sheet flow, swale, stream, channel, pipe, pond; size, diameter, surface area Drainage basin, vegetation, cover, depth, type of sensitive area, volume % Ft. Constrictions, under capacity, ponding, overtopping, flooding, habitat or organism destruction, scouring, bank sloughing, sedimentation, incision, other erosion Tributary area, likelihood of problem, overflow pathways, potential impacts 1. Sheetflow to the southeast corner of the site Discharges to existing wetland 2 0 - 10 None Noted None Noted 2. Storm Pond Flows from Wetland into Pond 0.5 500 None Noted None Noted 3. Catch Basin Pond Outlet Structure 0 550 None Noted None Noted 4. Catch Basin Pond Outlet Structure 0 550 None Noted None Noted 5. 24-inch pipe Flows from structure to ditch (south) unknown 575 None Noted None Noted 6. Vegetated Ditch Flows from pipe to structure (south) 2 575 None Noted None Noted 7. Catch Basin Flows from ditch to pipe (west) N/a 875 None Noted None Noted 8. 12-inch pipe Flows from structure to structure (east) 0.60 875 None Noted None Noted 9. 36-inch pipe Flows from structure to structure (south) 0.70 550-875 None Noted None Noted 10. Stormwater Manhole Flows from structure to structure (south) 0.22 875 None Noted None Noted Solid lid 11. 36-inch pipe Flows from structure to structure (south) 0.70 1320 None Noted None Noted Continues south then east eventually rejoining Maplewood Creek 160
161
15432.005.doc
TASK 4 DRAINAGE SYSTEM DESCRIPTION AND PROBLEM DESCRIPTIONS
Runoff leaves the site by discharging east into Maplewood Creek. Maplewood Creek continues south
and eventually joins another branch of Maplewood Creek before it flows through the Maplewood Golf
Course and discharges into the Cedar River.
The drainage complaints were forwarded to this office by Gary Fink, City of Renton Utility Systems
Division – Surface Water Utility and are located on the following pages of this report; however, none of
them were within ¼ mile downstream of the project site. They were placed into this report for reference
and there are no anticipated problems associated with the development of this project site.
162
163
1
Karen Harris
From:Colleen Allen
Sent:Thursday, October 16, 2014 9:42 AM
To:Karen Harris
Subject:FW: Request for Drainage Complaints / Storage One Project / BCE #12740
Attachments:12740 Storage One - Renton.pdf; 15432 email from Gary.pdf; AreaMap_Complaints.pdf
Follow Up Flag:Follow up
Flag Status:Flagged
From: Gary Fink [mailto:GFink@Rentonwa.gov]
Sent: Thursday, October 16, 2014 9:36 AM
To: Colleen Allen
Cc: Steve Lee
Subject: RE: Request for Drainage Complaints / Storage One Project / BCE #12740
Good Morning Colleen,
Review of subject parcels, 152305-9002 & 9178, do not show any significant drainage issues other than those specified
in the 2012 e-mail you referenced. Review of the King County IMap drainage complaints map indicated a 1989
complaint regarding fill on the adjacent parcel 152305-9112, and an unspecified 2011 water quality issue on adjacent lot
152305-9231. Renton Maintenance division notes a history of water overtopping of NE 4th St from the wetland north of
NE 4th St, across from the subject parcels, during severe storm events.
Please note that the above information provided is sourced from recorded issues logged in City of Renton drainage
complaint records, City Maintenance records, & King County IMap drainage complaint maps and cannot be deemed a
comprehensive list of all past issues.
Best Regards,
Gary Fink
City of Renton
Utility Systems Division - Surface Water Utility
Phone:(425) 430-7392 / Fax:(425) 430-7241
GFink@RentonWa.gov
From: Colleen Allen [mailto:callen@barghausen.com]
Sent: Tuesday, October 14, 2014 4:06 PM
To: Gary Fink
Cc: Karen Harris
Subject: FW: Request for Drainage Complaints / Storage One Project / BCE #12740
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2
Hi Gary. I’m following up on the email I sent you below. Any progress on researching the drainage complaints?
Colleen
From: Colleen Allen
Sent: Tuesday, October 07, 2014 1:56 PM
To: Gary Fink (GFink@Rentonwa.gov)
Cc: Karen Harris (kharris@barghausen.com)
Subject: Request for Drainage Complaints / Storage One Project / BCE #12740
Hi Gary. We are requesting drainage complaints for two adjacent parcels in Renton:
152305-9002 (no address)
152305-9178 (13839 S.E. 128th Street)
This site is roughly 500 feet east of the 4th and Duvall intersection and has the same
downstream drainage path as a site for which we requested drainage complaints back in
September 2012 (see attached). Hopefully, there haven’t been any new drainage complaints.
Thanks for your help!
---------------------------------
Colleen Allen
Engineering Assistant
Barghausen Consulting Engineers, Inc.
18215 72nd Avenue South
Kent, WA 98032
(425) 251-6222 - Phone
(425) 251-8782 - Fax
http://www.barghausen.com
---------------------------------
165
1
Colleen Allen
From:Karen Harris
Sent:Monday, October 06, 2014 3:36 PM
To:Colleen Allen
Subject:RE: Drainage Complaints- 4th & Duvall, Renton -Question / BCE #15432
Would you email Gary about the 12740 site, it is roughly 500 feet east of the 4th and Duvall intersection and has the
same downstream drainage path? Hopefully there haven’t been any new drainage complaints. ☺
Thanks,
Karen
From: Colleen Allen
Sent: Friday, September 14, 2012 3:12 PM
To: File
Cc: Karen Harris
Subject: FW: Drainage Complaints- 4th & Duvall, Renton -Question / BCE #15432
Karen, I will also save these in Filing.
From: Gary Fink [mailto:GFink@Rentonwa.gov]
Sent: Friday, September 14, 2012 3:05 PM
To: Colleen Allen
Subject: RE: Drainage Complaint Request - 4th & Duvall, Renton -Question
Good Afternoon Colleen,
Per the Renton manual, I’ve reviewed drainage issues for a distance of one mile downstream of your project at NE 4th
Ave & Duvall Ave NE. While the manual requires one mile downstream, I’ve reviewed to a radius of one mile as the
remainder of the course runs through Maplewood Creek channel.
The drainage course reviewed is as follows:
From parcel #1523059124, east on NE 4th Ave approximately 650’ to an outfall contained in a drainage easement.
South from NE 4th Ave, approximately 990’ via channel to a City-maintained detention facility.
South from detention pond via conveyance appr. 910’ along Field Avenue undeveloped right-of-way, turning southeast
across residential property to NE 1st St.
East on NE 1st St, South on Hoquiam Ave NE
Outfall to tributary of Maplewood Creek, South of SE 2nd St.
Maplewood Creek to City of Renton Maplewood sedimentation pond, continuing to Cedar River.
We have reports of minor drainage issues at properties located on NE 2nd Ct & NE 1st Ct. All occurred prior to 2006
annexation:
NE 2nd Ct – 4901, 4907, , 5003: Localized flooding due to plugged roadside culverts and ditch line. 4921:
Localized flooding on property due to fallen trees and plugged seasonal stream channel.
NE 1st Ct – 4904, 4905, 4910, 4913: Localized backyard flooding due to depression. Addressed through builder.
Maplewood Creek Sedimentation pond – heavy siltation due to erosion for storm events. Maintained annually
as needed.
166
2
Please feel free to contact me if you need further information.
Best Regards,
Gary Fink
City of Renton
Utility Systems Division - Surface Water Utility
Phone:(425) 430-7392 / Fax:(425) 430-7241
GFink@RentonWa.gov
From: Colleen Allen [mailto:callen@barghausen.com]
Sent: Thursday, September 13, 2012 2:54 PM
To: Gary Fink
Cc: Karen Harris; File
Subject: RE: Drainage Complaint Request - 4th & Duvall, Renton -Question
Gary, page 2-10 of the City of Renton Drainage Manual requires a 1-mile radius for the Task 2 Resource Review of a Level
1 Off-Site Drainage Analysis. Thank you.
Colleen
From: Gary Fink [mailto:GFink@Rentonwa.gov]
Sent: Thursday, September 13, 2012 2:47 PM
To: Colleen Allen
Subject: Drainage Complaint Request - 4th & Duvall, Renton -Question
Hi Colleen,
I’m pulling the information you’re requested together today, my apologies for the delay. Just wanted to confirm that
you were looking for drainage issues within a one mile radius of 4th & Duvall. Typical request in a ¼-mile radius.
Thanks,
Gary Fink
City of Renton
Utility Systems Division - Surface Water Utility
Phone:(425) 430-7392 / Fax:(425) 430-7241
GFink@RentonWa.gov
167
iMAP
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.
Date: 10/16/2014 Source: King County iMAP - Stormwater (http://www.metrokc.gov/GIS/iMAP)
COMMENTS: Drainage Complaint History - Storage One Project
168
iMAP
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.
Date: 9/15/2014 Source: King County iMAP - Property Information (http://www.metrokc.gov/GIS/iMAP)
169
iMAP
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.
Date: 9/15/2014 Source: King County iMAP - Property Information (http://www.metrokc.gov/GIS/iMAP)
170
171
12740.008.doc
4.0 FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN
A. Existing Site Hydrology
Of the 1.83 acre site, only 1.34 acres will be developed and therefore will be modeled as
till forest for pre-developed condition. The flow control facility will be located near the
southwest corner of the project site and will discharge to the existing stream along the
east site boundary.
A-1 Predeveloped Hourly Time Step Modeling Input
1.34 Acres - Till Forest - SeaTac
A-2 Predeveloped Hourly Time Step Modeling Output
Q2 = 0.037 cfs Q25 = 0.084 cfs
Q10 = 0.065 cfs Q100 = 0.108 cfs
See attached print for additional return periods
B. Developed Site Hydrology
Under developed conditions, the site has 0.79 acres of impervious and 0.38 acres of
landscape. Because this site is using a rain garden as a flow control BMP, 50 percent of
the roof area being directed to it is being modeled as pervious landscape area. For the
modular grid pavement, that area is modelled as grass. See the detention and water
quality sizing criteria on the following pages of this report.
B-2 Developed Time Step Modeling Input
0.76 Acres Impervious, 0.41 Acres Till Grass - SeaTac
B-3 Developed Hourly Time Step Modeling Output
Q2 = 0.221 cfs Q25 = 0.266 cfs
Q10 = 0.287 cfs Q100 = 0.446 cfs
See attached print for additional return periods
B-4 Bypass Input
0.05 Acres Impervious, 0.12 Acres Till Grass - SeaTac
172
12740.008.doc
B-5 Bypass Output
Q2 = 0.019 cfs Q25 = 0.024 cfs
Q10 = 0.028 cfs Q100 = 0.049 cfs
See attached print for additional return periods
B-6 Discharge from Pond
Q2 = 0.015 cfs Q25 = 0.065 cfs
Q10 = 0.059 cfs Q100 = 0.070 cfs
B-7 Discharge from Site
Discharge from site includes pond outlet and bypass.
Q2 = 0.029 cfs Q25 = 0.072 cfs
Q10 = 0.080 cfs Q100 = 0.099 cfs
C. Performance Standards
The Area-Specific Flow Control Standard required for this project site is determined to be
Flow Control Duration Standard – Matching Forested. The applicable conveyance
system capacity standard was mentioned in the Conditions and Requirements Summary,
which is to size the on-site conveyance system by the Rational Method utilizing an initial
time of concentration of 6.3 minutes and a Manning's "n" value of 0.014 with the 100-year
precipitation. The Area-Specific Water Quality Treatments Menu followed for this project
was the Enhanced Basic Water Quality Menu, and the treatment selected is to use a
DOE approved modular wetland.
D. Flow Control System
D-1 Flow Control BMP Selection and Design
The Flow Control BMPs for this site will be sized to treat runoff from 40 percent of the site
impervious area. This will be accomplished with a rain garden, modular grid pavement,
and permeable pavement. Flow control for this project will be in a detention pond utilizing
4 feet of live storage. Discharge will be through a control structure and then to a modular
wetland unit for water quality treatment. The required area to be treated by BMPs is
13,795 square feet.
173
12740.008.doc
D-2 Flow Control Facility Design Output
A total of 13,795 square feet is required to be treated by the BMPs, 13,870
square feet is provided. A summary of BMPs and their sizing is attached in the
following pages.
D-2.1 Raingarden
The raingarden accepts 8,956 square feet of impervious surface and has a
required volume of 2,239 cubic feet.
D-2.2 Modular Grid Pavement
There will be a total of 2,690 square feet of modular grid pavement installed on
the project site.
D-2.3 Permeable Pavement
There will be a total of 2,224 square feet of permeable pavement installed in the
parking lot. 1,900 square feet will be installed in the parking stalls in front of the
pond and 324 square feet will be installed in parking stalls in near the building.
E. Water Quality System
The Enhanced Basic Water Quality requirement will be achieved with a modular wetland
unit. Sizing calculations for the modular wetland are included. The facility is sized to
treat the full 2-yr release rate from the pond per the KCSWDM section 6.2.1.
174
175
12740.003.doc
FLOW CONTROL BMP SIZING
Site Area = 79,715 sf
20% of site area = 15,943 sf
Site Impervious area = 34,487 sf
40% of the site impervious area = 13,795 sf
Therefore 40% of the site impervious area will be used in sizing the Flow Control BMP
Rain Garden
A portion of the building roof will be sent to the rain garden
Impervious area to the rain garden = 8,956 sf
Rain Garden volume required = Impervious area x 3 inches = 2,239 cf
Rain Garden volume provided = 2,239 cf (1,839 cf in large rain garden and 400 cf in planter)
Maximum depth = 12 inches
Grassed Modular Grid Pavement area = 2,690 SF (2,133 sf to pond, 557 sf to bypass)
Permeable Pavement = 2,224 sf (1,900 by pond, 324 sf near building)
Total treated area = 13,870 SF
176
Rain Garden (5/12/16)3:1 side slopeselevcell 1cell 2cell 3planter 1planter 2total areavolumesum volume397.5530510222400016620039876568436840002217969.75969.75398.51020878563400028611269.52239.25177
15432.001.doc
DETENTION VAULT CALCULATIONS
178
12740.003.doc
DETENTION AND WATER QUALITY SIZING CRITERIA
Flow Control Duration Standard – Matching Forested Site Conditions
Pre-Developed:
1.34 acres of till forest
Developed:
Bypass = 0.17 acres (0.013 ac modular grid pavement)
0.05 ac impervious
0.12 ac grass/pervious
To Pond = 1.17 acres
0.79 acres of on-site impervious
0.38 acres of landscape (includes pond and rain garden areas)
Total = 1.17 acres = 0.79 + 0.38
Modular grid pavement to be modeled as grass = 0.05 ac
= 0.79 - 0.05 = 0.74 ac impervious
= 0.38 + 0.05 = 0.43 ac pervious
Roof Area to rain garden to be modeled as 50% grass, 50% impervious = 0.21 ac
= 0.105 ac impervious
0.74 - 0.105 = 0.635 ac impervious
= 0.105 ac grass
0.43 + 0.105 = 0.535 ac pervious
Pervious Pavement to be modeled as 50% grass, 50% impervious = 0.05 ac
= 0.61 ac impervious
0.635 - 0.025 = 0.61 ac impervious
0.535 + 0.025 = 0.56 ac grass
Pond is approximately 0.15 acres, model as impervious for flow control
179
12740.003.doc
For modeling:
= 0.61 + 0.15 = 0.76 acres impervious
= 0.56 - 0.15 = 0.41 acres grass
The KCRTS calculations are on the following pages.
180
181
182
183
Retention/Detention Facility
Type of Facility: Detention Pond
Side Slope: 2.00 H:1V
Pond Bottom Length: 75.00 ft
Pond Bottom Width: 50.00 ft
Pond Bottom Area: 3750. sq. ft
Top Area at 1 ft. FB: 6486. sq. ft
0.149 acres
Effective Storage Depth: 3.75 ft
Stage 0 Elevation: 0.00 ft
Storage Volume: 17859. cu. ft
0.410 ac-ft
Riser Head: 3.65 ft
Riser Diameter: 12.00 inches
Number of orifices: 2
Full Head Pipe
Orifice # Height Diameter Discharge Diameter
(ft) (in) (CFS) (in)
1 0.00 0.60 0.019
2 2.70 1.45 0.057 4.0
Top Notch Weir: None
Outflow Rating Curve: None
Stage Elevation Storage Discharge Percolation Surf Area
(ft) (ft) (cu. ft) (ac-ft) (cfs) (cfs) (sq. ft)
0.00 0.00 378. 0.009 0.000 0.00 3800.
0.01 0.01 416. 0.010 0.001 0.00 3805.
0.02 0.02 454. 0.010 0.001 0.00 3810.
0.03 0.03 492. 0.011 0.002 0.00 3815.
0.04 0.04 530. 0.012 0.002 0.00 3820.
0.05 0.05 568. 0.013 0.002 0.00 3825.
0.15 0.15 953. 0.022 0.004 0.00 3876.
0.25 0.25 1343. 0.031 0.005 0.00 3927.
0.35 0.35 1739. 0.040 0.006 0.00 3978.
0.45 0.45 2139. 0.049 0.007 0.00 4030.
0.55 0.55 2545. 0.058 0.007 0.00 4082.
0.65 0.65 2955. 0.068 0.008 0.00 4134.
0.75 0.75 3371. 0.077 0.008 0.00 4187.
0.85 0.85 3793. 0.087 0.009 0.00 4239.
0.95 0.95 4219. 0.097 0.010 0.00 4293.
1.05 1.05 4651. 0.107 0.010 0.00 4346.
1.15 1.15 5089. 0.117 0.010 0.00 4400.
1.25 1.25 5531. 0.127 0.011 0.00 4454.
1.35 1.35 5979. 0.137 0.011 0.00 4509.
1.45 1.45 6433. 0.148 0.012 0.00 4563.
1.55 1.55 6892. 0.158 0.012 0.00 4619.
1.65 1.65 7357. 0.169 0.013 0.00 4674.
1.75 1.75 7827. 0.180 0.013 0.00 4730.
1.85 1.85 8303. 0.191 0.013 0.00 4786.
1.95 1.95 8784. 0.202 0.014 0.00 4842.
2.05 2.05 9271. 0.213 0.014 0.00 4899.
2.15 2.15 9764. 0.224 0.014 0.00 4956.
2.25 2.25 10262. 0.236 0.015 0.00 5013.
2.35 2.35 10767. 0.247 0.015 0.00 5071.
2.45 2.45 11277. 0.259 0.015 0.00 5129.
2.55 2.55 11792. 0.271 0.016 0.00 5187.
184
2.65 2.65 12314. 0.283 0.016 0.00 5246.
2.70 2.70 12577. 0.289 0.016 0.00 5275.
2.72 2.72 12683. 0.291 0.016 0.00 5287.
2.73 2.73 12736. 0.292 0.018 0.00 5293.
2.75 2.75 12842. 0.295 0.020 0.00 5305.
2.76 2.76 12895. 0.296 0.023 0.00 5311.
2.78 2.78 13001. 0.298 0.027 0.00 5323.
2.79 2.79 13054. 0.300 0.032 0.00 5329.
2.81 2.81 13161. 0.302 0.035 0.00 5340.
2.82 2.82 13214. 0.303 0.036 0.00 5346.
2.84 2.84 13321. 0.306 0.037 0.00 5358.
2.94 2.94 13860. 0.318 0.044 0.00 5418.
3.04 3.04 14405. 0.331 0.050 0.00 5478.
3.14 3.14 14956. 0.343 0.055 0.00 5538.
3.24 3.24 15513. 0.356 0.059 0.00 5598.
3.34 3.34 16076. 0.369 0.063 0.00 5659.
3.44 3.44 16644. 0.382 0.067 0.00 5721.
3.54 3.54 17220. 0.395 0.071 0.00 5782.
3.64 3.64 17801. 0.409 0.074 0.00 5844.
3.65 3.65 17859. 0.410 0.074 0.00 5850.
3.75 3.75 18447. 0.423 0.385 0.00 5912.
3.85 3.85 19042. 0.437 0.951 0.00 5975.
3.95 3.95 19642. 0.451 1.680 0.00 6037.
4.05 4.05 20249. 0.465 2.480 0.00 6101.
4.15 4.15 20863. 0.479 2.760 0.00 6164.
4.25 4.25 21482. 0.493 3.020 0.00 6228.
4.35 4.35 22108. 0.508 3.260 0.00 6292.
4.45 4.45 22741. 0.522 3.480 0.00 6356.
4.55 4.55 23379. 0.537 3.690 0.00 6421.
4.65 4.65 24025. 0.552 3.880 0.00 6486.
4.75 4.75 24677. 0.566 4.070 0.00 6551.
4.85 4.85 25335. 0.582 4.250 0.00 6617.
4.95 4.95 26000. 0.597 4.420 0.00 6683.
5.05 5.05 26672. 0.612 4.580 0.00 6749.
5.15 5.15 27350. 0.628 4.740 0.00 6816.
5.25 5.25 28035. 0.644 4.900 0.00 6883.
5.35 5.35 28726. 0.659 5.050 0.00 6950.
5.45 5.45 29425. 0.676 5.190 0.00 7018.
5.55 5.55 30130. 0.692 5.330 0.00 7086.
5.65 5.65 30842. 0.708 5.470 0.00 7154.
Hyd Inflow Outflow Peak Storage
Stage Elev (Cu-Ft) (Ac-Ft)
1 0.45 0.07 3.51 3.51 17066. 0.392
2 0.22 0.07 3.39 3.39 16370. 0.376
3 0.27 0.06 3.25 3.25 15552. 0.357
4 0.29 0.04 2.93 2.93 13808. 0.317
5 0.23 0.02 2.47 2.47 11397. 0.262
6 0.18 0.01 2.18 2.18 9926. 0.228
7 0.24 0.01 2.22 2.22 10107. 0.232
8 0.20 0.01 1.43 1.43 6339. 0.146
Hyd R/D Facility Tributary Reservoir POC Outflow
Outflow Inflow Inflow Target Calc
1 0.07 0.05 ******** 0.11 0.07
2 0.07 0.02 ******** ******* 0.08
3 0.06 0.03 ******** ******* 0.07
4 0.04 0.02 ******** ******* 0.05
5 0.02 0.02 ******** ******* 0.04
6 0.01 0.02 ******** ******* 0.03
185
7 0.01 0.02 ******** ******* 0.03
8 0.01 0.01 ******** ******* 0.02
----------------------------------
Route Time Series through Facility
Inflow Time Series File:12740-dev.tsf
Outflow Time Series File:rdout
POC Time Series File:dsout
Inflow/Outflow Analysis
Peak Inflow Discharge: 0.446 CFS at 6:00 on Jan 9 in Year 8
Peak Outflow Discharge: 0.070 CFS at 14:00 on Jan 9 in Year 8
Peak Reservoir Stage: 3.51 Ft
Peak Reservoir Elev: 3.51 Ft
Peak Reservoir Storage: 17071. Cu-Ft
: 0.392 Ac-Ft
Add Time Series:12740-bypass.tsf
Peak Summed Discharge: 0.099 CFS at 9:00 on Jan 9 in Year 8
Point of Compliance File:dsout.tsf
Flow Frequency Analysis
Time Series File:rdout.tsf
Project Location:Sea-Tac
---Annual Peak Flow Rates--- -----Flow Frequency Analysis-------
Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob
(CFS) (CFS) (ft) Period
0.065 2 2/09/01 20:00 0.070 3.51 1 100.00 0.990
0.014 7 1/07/02 4:00 0.065 3.39 2 25.00 0.960
0.059 3 3/06/03 22:00 0.059 3.25 3 10.00 0.900
0.012 8 8/26/04 8:00 0.043 2.93 4 5.00 0.800
0.015 6 1/08/05 6:00 0.015 2.47 5 3.00 0.667
0.015 5 1/19/06 14:00 0.015 2.22 6 2.00 0.500
0.043 4 11/24/06 9:00 0.014 2.18 7 1.30 0.231
0.070 1 1/09/08 14:00 0.012 1.43 8 1.10 0.091
Computed Peaks 0.068 3.47 50.00 0.980
Flow Frequency Analysis
Time Series File:dsout.tsf
Project Location:Sea-Tac
---Annual Peak Flow Rates--- -----Flow Frequency Analysis-------
Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob
(CFS) (CFS) Period
0.080 2 2/09/01 18:00 0.099 1 100.00 0.990
0.029 6 1/05/02 16:00 0.080 2 25.00 0.960
0.072 3 3/06/03 19:00 0.072 3 10.00 0.900
0.025 8 8/26/04 2:00 0.052 4 5.00 0.800
0.027 7 1/05/05 8:00 0.037 5 3.00 0.667
0.037 5 1/18/06 16:00 0.029 6 2.00 0.500
0.052 4 11/24/06 7:00 0.027 7 1.30 0.231
0.099 1 1/09/08 9:00 0.025 8 1.10 0.091
Computed Peaks 0.092 50.00 0.980
Flow Duration from Time Series File:rdout.tsf
Cutoff Count Frequency CDF Exceedence_Probability
CFS % % %
0.001 27634 45.065 45.065 54.935 0.549E+00
0.003 7757 12.650 57.715 42.285 0.423E+00
0.005 5495 8.961 66.676 33.324 0.333E+00
0.006 5061 8.253 74.930 25.070 0.251E+00
186
0.008 6748 11.005 85.934 14.066 0.141E+00
0.010 2114 3.447 89.382 10.618 0.106E+00
0.012 2827 4.610 93.992 6.008 0.601E-01
0.014 2018 3.291 97.283 2.717 0.272E-01
0.015 1154 1.882 99.165 0.835 0.835E-02
0.017 324 0.528 99.693 0.307 0.307E-02
0.019 23 0.038 99.731 0.269 0.269E-02
0.021 16 0.026 99.757 0.243 0.243E-02
0.023 9 0.015 99.772 0.228 0.228E-02
0.024 9 0.015 99.786 0.214 0.214E-02
0.026 6 0.010 99.796 0.204 0.204E-02
0.028 5 0.008 99.804 0.196 0.196E-02
0.030 2 0.003 99.808 0.192 0.192E-02
0.032 2 0.003 99.811 0.189 0.189E-02
0.033 6 0.010 99.821 0.179 0.179E-02
0.035 5 0.008 99.829 0.171 0.171E-02
0.037 11 0.018 99.847 0.153 0.153E-02
0.039 7 0.011 99.858 0.142 0.142E-02
0.041 8 0.013 99.871 0.129 0.129E-02
0.042 7 0.011 99.883 0.117 0.117E-02
0.044 8 0.013 99.896 0.104 0.104E-02
0.046 3 0.005 99.901 0.099 0.995E-03
0.048 5 0.008 99.909 0.091 0.913E-03
0.050 6 0.010 99.918 0.082 0.815E-03
0.051 7 0.011 99.930 0.070 0.701E-03
0.053 8 0.013 99.943 0.057 0.571E-03
0.055 8 0.013 99.956 0.044 0.440E-03
0.057 5 0.008 99.964 0.036 0.359E-03
0.059 5 0.008 99.972 0.028 0.277E-03
0.060 7 0.011 99.984 0.016 0.163E-03
0.062 3 0.005 99.989 0.011 0.114E-03
0.064 3 0.005 99.993 0.007 0.652E-04
Flow Duration from Time Series File:dsout.tsf
Cutoff Count Frequency CDF Exceedence_Probability
CFS % % %
0.001 29386 47.922 47.922 52.078 0.521E+00
0.003 7262 11.843 59.765 40.235 0.402E+00
0.006 6137 10.008 69.773 30.227 0.302E+00
0.008 6210 10.127 79.901 20.099 0.201E+00
0.010 4420 7.208 87.109 12.891 0.129E+00
0.012 3403 5.550 92.658 7.342 0.734E-01
0.014 2187 3.567 96.225 3.775 0.378E-01
0.017 1167 1.903 98.128 1.872 0.187E-01
0.019 644 1.050 99.178 0.822 0.822E-02
0.021 183 0.298 99.477 0.523 0.523E-02
0.023 83 0.135 99.612 0.388 0.388E-02
0.025 36 0.059 99.671 0.329 0.329E-02
0.028 32 0.052 99.723 0.277 0.277E-02
0.030 23 0.038 99.760 0.240 0.240E-02
0.032 13 0.021 99.781 0.219 0.219E-02
0.034 8 0.013 99.795 0.205 0.205E-02
0.037 8 0.013 99.808 0.192 0.192E-02
0.039 9 0.015 99.822 0.178 0.178E-02
0.041 8 0.013 99.835 0.165 0.165E-02
0.043 8 0.013 99.848 0.152 0.152E-02
0.045 9 0.015 99.863 0.137 0.137E-02
0.048 8 0.013 99.876 0.124 0.124E-02
0.050 6 0.010 99.886 0.114 0.114E-02
0.052 5 0.008 99.894 0.106 0.106E-02
187
0.054 7 0.011 99.905 0.095 0.946E-03
0.056 7 0.011 99.917 0.083 0.832E-03
0.059 10 0.016 99.933 0.067 0.669E-03
0.061 7 0.011 99.945 0.055 0.554E-03
0.063 6 0.010 99.954 0.046 0.457E-03
0.065 8 0.013 99.967 0.033 0.326E-03
0.068 3 0.005 99.972 0.028 0.277E-03
0.070 4 0.007 99.979 0.021 0.212E-03
0.072 4 0.007 99.985 0.015 0.147E-03
0.074 3 0.005 99.990 0.010 0.978E-04
0.076 4 0.007 99.997 0.003 0.326E-04
0.079 1 0.002 99.998 0.002 0.163E-04
Duration Comparison Anaylsis
Base File: 12740-pre.tsf
New File: dsout.tsf
Cutoff Units: Discharge in CFS
-----Fraction of Time----- ---------Check of Tolerance-------
Cutoff Base New %Change Probability Base New %Change
0.018 | 0.97E-02 0.95E-02 -1.9 | 0.97E-02 0.018 0.018 -1.0
0.023 | 0.63E-02 0.39E-02 -38.9 | 0.63E-02 0.023 0.020 -13.6
0.029 | 0.49E-02 0.26E-02 -47.4 | 0.49E-02 0.029 0.021 -25.1
0.034 | 0.37E-02 0.21E-02 -42.9 | 0.37E-02 0.034 0.024 -28.2
0.039 | 0.29E-02 0.18E-02 -38.4 | 0.29E-02 0.039 0.027 -30.2
0.044 | 0.22E-02 0.15E-02 -33.8 | 0.22E-02 0.044 0.032 -27.6
0.049 | 0.15E-02 0.12E-02 -20.7 | 0.15E-02 0.049 0.043 -11.4
0.054 | 0.10E-02 0.96E-03 -4.8 | 0.10E-02 0.054 0.053 -2.4
0.059 | 0.62E-03 0.67E-03 7.9 | 0.62E-03 0.059 0.060 1.9
0.064 | 0.34E-03 0.41E-03 19.0 | 0.34E-03 0.064 0.065 1.9
0.069 | 0.21E-03 0.23E-03 7.7 | 0.21E-03 0.069 0.071 2.3
0.074 | 0.16E-03 0.82E-04 -50.0 | 0.16E-03 0.074 0.072 -3.3
0.079 | 0.11E-03 0.16E-04 -85.7 | 0.11E-03 0.079 0.073 -7.6
0.084 | 0.16E-04 0.00E+00 -100.0 | 0.16E-04 0.084 0.079 -5.8
Maximum positive excursion = 0.002 cfs ( 3.4%)
occurring at 0.065 cfs on the Base Data:12740-pre.tsf
and at 0.067 cfs on the New Data:dsout.tsf
Maximum negative excursion = 0.013 cfs (-30.9%)
occurring at 0.041 cfs on the Base Data:12740-pre.tsf
and at 0.028 cfs on the New Data:dsout.tsf
----------------------------------
Route Time Series through Facility
Inflow Time Series File:12740-dev.tsf
Outflow Time Series File:rdout
POC Time Series File:dsout
Inflow/Outflow Analysis
Peak Inflow Discharge: 0.446 CFS at 6:00 on Jan 9 in Year 8
Peak Outflow Discharge: 0.070 CFS at 14:00 on Jan 9 in Year 8
Peak Reservoir Stage: 3.51 Ft
Peak Reservoir Elev: 3.51 Ft
Peak Reservoir Storage: 17071. Cu-Ft
: 0.392 Ac-Ft
Add Time Series:12740-bypass.tsf
Peak Summed Discharge: 0.099 CFS at 9:00 on Jan 9 in Year 8
Point of Compliance File:dsout.tsf
Flow Frequency Analysis
188
Time Series File:rdout.tsf
Project Location:Sea-Tac
---Annual Peak Flow Rates--- -----Flow Frequency Analysis-------
Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob
(CFS) (CFS) (ft) Period
0.065 2 2/09/01 20:00 0.070 3.51 1 100.00 0.990
0.014 7 1/07/02 4:00 0.065 3.39 2 25.00 0.960
0.059 3 3/06/03 22:00 0.059 3.25 3 10.00 0.900
0.012 8 8/26/04 8:00 0.043 2.93 4 5.00 0.800
0.015 6 1/08/05 6:00 0.015 2.47 5 3.00 0.667
0.015 5 1/19/06 14:00 0.015 2.22 6 2.00 0.500
0.043 4 11/24/06 9:00 0.014 2.18 7 1.30 0.231
0.070 1 1/09/08 14:00 0.012 1.43 8 1.10 0.091
Computed Peaks 0.068 3.47 50.00 0.980
Flow Frequency Analysis
Time Series File:dsout.tsf
Project Location:Sea-Tac
---Annual Peak Flow Rates--- -----Flow Frequency Analysis-------
Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob
(CFS) (CFS) Period
0.080 2 2/09/01 18:00 0.099 1 100.00 0.990
0.029 6 1/05/02 16:00 0.080 2 25.00 0.960
0.072 3 3/06/03 19:00 0.072 3 10.00 0.900
0.025 8 8/26/04 2:00 0.052 4 5.00 0.800
0.027 7 1/05/05 8:00 0.037 5 3.00 0.667
0.037 5 1/18/06 16:00 0.029 6 2.00 0.500
0.052 4 11/24/06 7:00 0.027 7 1.30 0.231
0.099 1 1/09/08 9:00 0.025 8 1.10 0.091
Computed Peaks 0.092 50.00 0.980
Flow Duration from Time Series File:rdout.tsf
Cutoff Count Frequency CDF Exceedence_Probability
CFS % % %
0.001 27634 45.065 45.065 54.935 0.549E+00
0.003 7757 12.650 57.715 42.285 0.423E+00
0.005 5495 8.961 66.676 33.324 0.333E+00
0.006 5061 8.253 74.930 25.070 0.251E+00
0.008 6748 11.005 85.934 14.066 0.141E+00
0.010 2114 3.447 89.382 10.618 0.106E+00
0.012 2827 4.610 93.992 6.008 0.601E-01
0.014 2018 3.291 97.283 2.717 0.272E-01
0.015 1154 1.882 99.165 0.835 0.835E-02
0.017 324 0.528 99.693 0.307 0.307E-02
0.019 23 0.038 99.731 0.269 0.269E-02
0.021 16 0.026 99.757 0.243 0.243E-02
0.023 9 0.015 99.772 0.228 0.228E-02
0.024 9 0.015 99.786 0.214 0.214E-02
0.026 6 0.010 99.796 0.204 0.204E-02
0.028 5 0.008 99.804 0.196 0.196E-02
0.030 2 0.003 99.808 0.192 0.192E-02
0.032 2 0.003 99.811 0.189 0.189E-02
0.033 6 0.010 99.821 0.179 0.179E-02
0.035 5 0.008 99.829 0.171 0.171E-02
0.037 11 0.018 99.847 0.153 0.153E-02
0.039 7 0.011 99.858 0.142 0.142E-02
0.041 8 0.013 99.871 0.129 0.129E-02
0.042 7 0.011 99.883 0.117 0.117E-02
0.044 8 0.013 99.896 0.104 0.104E-02
189
0.046 3 0.005 99.901 0.099 0.995E-03
0.048 5 0.008 99.909 0.091 0.913E-03
0.050 6 0.010 99.918 0.082 0.815E-03
0.051 7 0.011 99.930 0.070 0.701E-03
0.053 8 0.013 99.943 0.057 0.571E-03
0.055 8 0.013 99.956 0.044 0.440E-03
0.057 5 0.008 99.964 0.036 0.359E-03
0.059 5 0.008 99.972 0.028 0.277E-03
0.060 7 0.011 99.984 0.016 0.163E-03
0.062 3 0.005 99.989 0.011 0.114E-03
0.064 3 0.005 99.993 0.007 0.652E-04
Flow Duration from Time Series File:dsout.tsf
Cutoff Count Frequency CDF Exceedence_Probability
CFS % % %
0.001 29386 47.922 47.922 52.078 0.521E+00
0.003 7262 11.843 59.765 40.235 0.402E+00
0.006 6137 10.008 69.773 30.227 0.302E+00
0.008 6210 10.127 79.901 20.099 0.201E+00
0.010 4420 7.208 87.109 12.891 0.129E+00
0.012 3403 5.550 92.658 7.342 0.734E-01
0.014 2187 3.567 96.225 3.775 0.378E-01
0.017 1167 1.903 98.128 1.872 0.187E-01
0.019 644 1.050 99.178 0.822 0.822E-02
0.021 183 0.298 99.477 0.523 0.523E-02
0.023 83 0.135 99.612 0.388 0.388E-02
0.025 36 0.059 99.671 0.329 0.329E-02
0.028 32 0.052 99.723 0.277 0.277E-02
0.030 23 0.038 99.760 0.240 0.240E-02
0.032 13 0.021 99.781 0.219 0.219E-02
0.034 8 0.013 99.795 0.205 0.205E-02
0.037 8 0.013 99.808 0.192 0.192E-02
0.039 9 0.015 99.822 0.178 0.178E-02
0.041 8 0.013 99.835 0.165 0.165E-02
0.043 8 0.013 99.848 0.152 0.152E-02
0.045 9 0.015 99.863 0.137 0.137E-02
0.048 8 0.013 99.876 0.124 0.124E-02
0.050 6 0.010 99.886 0.114 0.114E-02
0.052 5 0.008 99.894 0.106 0.106E-02
0.054 7 0.011 99.905 0.095 0.946E-03
0.056 7 0.011 99.917 0.083 0.832E-03
0.059 10 0.016 99.933 0.067 0.669E-03
0.061 7 0.011 99.945 0.055 0.554E-03
0.063 6 0.010 99.954 0.046 0.457E-03
0.065 8 0.013 99.967 0.033 0.326E-03
0.068 3 0.005 99.972 0.028 0.277E-03
0.070 4 0.007 99.979 0.021 0.212E-03
0.072 4 0.007 99.985 0.015 0.147E-03
0.074 3 0.005 99.990 0.010 0.978E-04
0.076 4 0.007 99.997 0.003 0.326E-04
0.079 1 0.002 99.998 0.002 0.163E-04
190
191
Detention Pond
5/23/2016
elev cell 1 total area volume sum volume
ft sf sf cf cf
394.25 4685 4685 0 0
394.5 4875 4875 1195 1195
395 5247 5247 2530.5 3725.5
395.5 5626 5626 2718.25 6443.75
396 6009 6009 2908.75 9352.5
396.5 6391 6391 3100 12452.5
397 6774 6774 3291.25 15743.75
397.5 7162 7162 3484 19227.75
398 7566 7566 3682 22909.75 14640 CF REQ.
399 8262 8262 7914 30823.75
192
WATER QUALITY CALCULATIONS
193
isLawr’\JIrDCommunity&EconomicDevelopmentDepartmentJune21,2016C.E.”Chip”Vincent,AdministratorMr.JasonHubbellBarghausenConsultingEngineers1821572ndAvenueSouthKent,WA98032RE:StorageOneon4thExpansion(U1500$468)—MWS-LinearModularWetlandStormwaterTreatmentSystemforPrivateUse-Adjustment2016-04DearMr.Hubbell:TheCityofRentonhascompletedreviewoftheadjustmentrequestforStorageOneon4thExpansion(U15008434)inaccordancewithCityadopted2009KingCountySurfaceWaterDesignManualandassociatedCityAmendments.Astheapplicant’sengineer,youarerequestinganadjustmentfromthe2009KingCountySurfaceWaterDesignManualtoSection6.1.2,EnhancedBasicWaterQualityMenu,requirements.Morespecifically,youarerequestinganadjustmentfortheimplementationoftheMWSLinearModularWetlandStormwaterTreatmentSystemlocatedonaprivatecommercialpropertythatwillbeownedandmaintainedbythepropertyowner(s).Findings:1.Theprojectsiteislocatedat4215NE4thStreet.Theprojectisacommerciallanduse,whichpertheCity’sAmendmentstothe2009KingCountySurfaceWaterDesignManualSection1.2.8.1,isrequiredtoprovideEnhancedBasicWaterQualityTreatment.2.ThesurfacewaterfromtheproposeddevelopmentwillbecollectedthenroutedthroughadetentionsystempriortoenteringtheMWS-LinearModularWetlandStormwaterTreatmentSystem.3.TheMWS-LinearModularWetlandStormwaterTreatmentSystem,andotheron-sitedrainagefacilitieswillbeprivatelyownedandmaintained.4.TheMWS-LinearModularWetlandStormwaterTreatmentSystemisnotanapprovedfacilityintheCity’sadoptedstormwatermanual,thereforeanadjustmentisrequiredtoallowtheuseoftheMWS-LinearModularWetlandRentonCityHall.1055SouthGradyWay.Renton,Washington98057.rentonwa.gov
Mr.JasonHubbellPage2of4June21,2016StormwaterTreatmentSystemonprivateorpubliclyownedandmaintainedstormsystems.5.TheWashingtonStateDepartmentofEcologyhasapprovedtheMWS-LinearModularWetlandStormwaterTreatmentSystemforGeneralUseLevelDesignationforBasic,Phosphorous,andEnhancedtreatment.Basedontheinformationprovidedintheenclosedadjustmentrequest,theMWS-LinearModularWetlandStormwaterTreatmentSystemisapprovedfortheproposedStorageOneon4thExpansionwiththefollowingconditions:Conditions:1.Thepropertyowner(s)isresponsibleforthemaintenanceandoperationoftheMWS-LinearModularWetlandStormwaterTreatmentSystem.2.Thepropertyowner(s)shallenterintoaservicecontractwithanapprovedcontractororLinearModularWetlandrepresentativeforthelongtermmaintenanceofthesystem.3.TheMWS-LinearModularWetlandinstalleddownstreamofdetentionshallbedesignedwithawaterqualitydesignflowrateofthefull2-yearreleaserateofthedetentionfacility.4.TheMWS-LinearModularWetlandStormwaterTreatmentSystemunitsshallbedesigned,assembled,installed,operatedandmaintainedinaccordancewiththeModularWetlandSystems,Inc.applicablemanualsanddocumentsandtheEcologyDecision.5.EachsiteplanmustundergoModularWetlandSystems,Inc.reviewandapprovalbeforesiteinstallation.ThisensuresthatsitegradingandslopeareappropriateforuseofaMWS-LinearModularWetlandStormwaterTreatmentSystemunit.6.MWS-LinearModularWetlandStormwaterSystemmediashallconformtothespecificationssubmittedto,andapprovedby,theWashingtonStateDepartmentofEcology.7.Facilityinspection,maintenance,andreportingarerequiredbytheCityofRentonSurfaceWaterUtilityforthePropertyOwnermaintainedMWS-LinearModularWetlandStormwaterTreatmentSysteminperpetuity.Thefacilityinspection,maintenanceandreportingisrequiredpertheEcologyNationalPollutantDischargeEliminationSystemPhaseIIMunicipalStormwaterPermit(SectionS5.C.4.c.iii).Facilityownersareresponsibleforensuringthat
Mr.JasonHubbellPage3of4June21,2016stormwaterfacilitiesareproperlymaintainedandfunctioningasdesignedandpermitted.8.TheMWS-LinearModularWetlandStormwaterTreatmentSystemshallbeinspectedandmaintainedinaccordancewithmanufacturerrecommendationsand,inaddition,beinspectedandmaintainedasdetailedbelow:a.Forthefirstyearafterconstruction,theMWS-LinearModularWetlandStormwaterTreatmentSystemshallbeinspectedeverysixmonthstoassureproperperformance.Inspectionreportswillbeusedtodeterminefuturesite-specificmaintenanceschedulesandrequirements.b.Followingthefirstyearofoperation,thefacilityowner(s)shallannuallyhavetheMWS-LinearModularWetlandStormwaterTreatmentSysteminspectedandmaintainedpertheproceduresinthemostrecentversionoftheMWS-LinearModularWetlandStormwaterTreatmentSystemOperationandMaintenanceManuals.AllwrittenrecordsoftheinspectionandmaintenanceshallbesubmittedtotheCityofRentonSurfaceWaterUtility,totheattentionofSurfaceWaterUtilityPrivateStormwaterFacilityInspectionProgram.IfmorefrequentinspectionandmaintenanceoftheMWS-LinearModularWetlandStormwaterTreatmentSystemisrequiredbythemanufacturerorisneededtoensureperformanceofthefacility,thentheadditionalinspectionandmaintenancereportscompletedwithintheyearshallbeprovidedwiththeannualreport.c.Uponcompletionofthetwo-yearinspectionperiod,afterconstructionoftheMWS-LinearModularWetlandStormwaterTreatmentSystem,theCitywillreviewtheinspectionreportandfacilitymaintenancelogtoreevaluatefutureinspectionfrequencyofthesystem.Theinformationwillbeusedtodetermineiftheminimuminspectionfrequencyofonceayearcanbeallowed.U.Maintenanceactivities,toassureproperperformanceoftheMWS-LinearModularWetlandStormwaterTreatmentSystem,shallbeasneeded,orasdeterminedintheannualinspection,tocomplywiththerequirementsinthe2009KingCountySurfaceWaterDesignManualformaintenanceofdrainagefacilities.Inaddition,maintenanceproceduresshouldfollowthosegiveninthemostrecentversionoftheMWS-LinearModularWetlandStormwaterTreatmentSystemOperationandMaintenanceManuals.
Mr.JasonHubbellPage4of4June21,20169.TheapplicantwillneedtosubmitaDrainageFacilityCovenanttoallowtheCityaccesstothefacilityforinspectionoftheprivateMWS-LinearModularWetlandStormwaterTreatmentSystemandotherstormwaterfacilitiesonthesitethatwillbeprivatelymaintained.TheDrainageFacilityCovenantmustbeapprovedforrecordingpriortotheCity’sutilitypermitbeingissuedfortheconstructionofthefacilities.Thisadjustmentapprovalletteristobeincludedwiththerecordedcovenant.TheDrainageFacilityCovenantcanbefoundinReferenceJoftheCityofRentonAmendmentstothe2009KingCountySurfaceWaterDesignManual.AsiteplanshowingthelocationofthetreatmentfacilitymustbeincludedasExhibitAwiththedeclarationofcovenant.ThesiteplanmustmeetallKingCountyrecordingdocumentrequirements(i.e.textsize,clarity,etc.).10.Alettersignedbythepropertyowner(s)agreeingtotherequiredinspectionandmaintenancescheduleisrequiredasaconditionofgrantingthisadjustment.ThelettershallbesubmittedtotheCitypriortoconstructionpermitapproval.11.Theapprovalofthisadjustmentdoesnotrelievetheapplicantfromothercity,state,orfederalrequirements.Ifyouhaveanyquestionsaboutthisadjustment,pleasecontactBrianneBannwarth,DevelopmentEngineeringManager,at(425)430-7299orRonStraka,SurfaceWaterUtilityEngineeringManager,at(425)430-7248.Sincerely,BrianneBannwart,P.E.RonStraka,P.E.‘DevelopmentEngineeringManagerSurfaceWaterUtilityEngineeringManagercc:LysHornsby,P.E.,UtilitySystemsDirectorMikeStenhouse,MaintenanceServicesDirectorRohiniNair,CivilEngineerIllClarkClose,SeniorPlannerStrickerCatoMurphyArchitects—ProjectApplicantH:\FiIeSys\SWP-SurfaceWaterProjects\SWP-27-SurfaceWaterProjects(CIP)\27-3129RentonStormwaterManual\ADJUSTMENTS\2016\2016-4StorageOne-PrivateModularWetland.doc
194
7 0.01 0.02 ******** ******* 0.03
8 0.01 0.01 ******** ******* 0.02
----------------------------------
Route Time Series through Facility
Inflow Time Series File:12740-dev.tsf
Outflow Time Series File:rdout
POC Time Series File:dsout
Inflow/Outflow Analysis
Peak Inflow Discharge: 0.446 CFS at 6:00 on Jan 9 in Year 8
Peak Outflow Discharge: 0.070 CFS at 14:00 on Jan 9 in Year 8
Peak Reservoir Stage: 3.51 Ft
Peak Reservoir Elev: 3.51 Ft
Peak Reservoir Storage: 17071. Cu-Ft
: 0.392 Ac-Ft
Add Time Series:12740-bypass.tsf
Peak Summed Discharge: 0.099 CFS at 9:00 on Jan 9 in Year 8
Point of Compliance File:dsout.tsf
Flow Frequency Analysis
Time Series File:rdout.tsf
Project Location:Sea-Tac
---Annual Peak Flow Rates--- -----Flow Frequency Analysis-------
Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob
(CFS) (CFS) (ft) Period
0.065 2 2/09/01 20:00 0.070 3.51 1 100.00 0.990
0.014 7 1/07/02 4:00 0.065 3.39 2 25.00 0.960
0.059 3 3/06/03 22:00 0.059 3.25 3 10.00 0.900
0.012 8 8/26/04 8:00 0.043 2.93 4 5.00 0.800
0.015 6 1/08/05 6:00 0.015 2.47 5 3.00 0.667
0.015 5 1/19/06 14:00 0.015 2.22 6 2.00 0.500
0.043 4 11/24/06 9:00 0.014 2.18 7 1.30 0.231
0.070 1 1/09/08 14:00 0.012 1.43 8 1.10 0.091
Computed Peaks 0.068 3.47 50.00 0.980
Flow Frequency Analysis
Time Series File:dsout.tsf
Project Location:Sea-Tac
---Annual Peak Flow Rates--- -----Flow Frequency Analysis-------
Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob
(CFS) (CFS) Period
0.080 2 2/09/01 18:00 0.099 1 100.00 0.990
0.029 6 1/05/02 16:00 0.080 2 25.00 0.960
0.072 3 3/06/03 19:00 0.072 3 10.00 0.900
0.025 8 8/26/04 2:00 0.052 4 5.00 0.800
0.027 7 1/05/05 8:00 0.037 5 3.00 0.667
0.037 5 1/18/06 16:00 0.029 6 2.00 0.500
0.052 4 11/24/06 7:00 0.027 7 1.30 0.231
0.099 1 1/09/08 9:00 0.025 8 1.10 0.091
Computed Peaks 0.092 50.00 0.980
Flow Duration from Time Series File:rdout.tsf
Cutoff Count Frequency CDF Exceedence_Probability
CFS % % %
0.001 27634 45.065 45.065 54.935 0.549E+00
0.003 7757 12.650 57.715 42.285 0.423E+00
0.005 5495 8.961 66.676 33.324 0.333E+00
0.006 5061 8.253 74.930 25.070 0.251E+00
195
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198
12740.008.doc
5.0 CONVEYANCE SYSTEM ANALYSIS AND DESIGN
The conveyance system for this project is sized to convey the 100-year storm event based on the
modified rational method with an initial time of concentration of 6.3 minutes. This site is
approximately 1.34 acres in size, which is significantly less than the 10-acre maximum
requirement for using the modified rational method. For this project, we are using the modified
rational method.
Backwater calculations are included to show the 0.19 foot of freeboard being provided for the 25-
yr storm event and that there will be no overtopping of the system in the 100-yr storm event.
Design requirements per the 2009 King County Storm Water Design Manual section 1.2.4.1 state
that new pipe systems shall be designed to convey at a minimum the 25-year event therefore the
conveyance system exceeds design requirements.
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200
12740-conveyance-25yr.xlsBARGHAUSEN CONSULTING ENGINEERS - PIPE FLOW CALCULATORusing the Rational Method & Manning FormulaKING COUNTY DESIGN FOR 25YEAR STORMJOB NAME: Storage One NOTE: ENTER DEFAULTS AND STORM DATA BEFORE BEGINNING JOB#: 12740 DEFAULTS C= 0.9 n= 0.014REVISED:5/18/2016 d=12Tc=6.3A= Contributing Area (Ac) Qd= Design Flow (cfs) COEFFICIENTS FOR THE RATIONAL METHOD "Ir"-EQUATIONC= Runoff Coefficient Qf= Full Capacity Flow (cfs)STORMAr BrTc= Time of Concentration (min) Vd= Velocity at Design Flow (fps) 2YR 1.58 0.58I= Intensity at Tc (in/hr) Vf= Velocity at Full Flow (fps) 10YR 2.44 0.64 PRECIP=4d= Diameter of Pipe (in) s= Slope of pipe (%) 25YR 2.66 0.65 Ar=2.66L= Length of Pipe (ft) n= Manning Roughness Coefficient 50YR 2.75 0.65 Br=0.65D= Water Depth at Qd (in) Tt= Travel Time at Vd (min) 100YR 2.61 0.63FROM TO A s L d Tc n C SUM A A*C SUM A*C I Qd QfQd/QfD/d D Vf Vd Tt====== ====== ====== ====== ================== ====== ====== ====== ===================== ====== ====== ====== ====== ====== ====== ====== ======CB2 CB7 0.21 0.51 35 12 6.3 0.014 0.9 0.21 0.19 0.19 3.22 0.61 2.360.2570.346 4.15 3.01 2.52 0.23CB8 CB7 0.07 0.50 20 12 6.5 0.014 0.9 0.28 0.06 0.25 3.14 0.79 2.340.3390.402 4.82 2.98 2.70 0.12CB7 CB3 0.30 0.50 62 12 6.7 0.014 0.9 0.58 0.27 0.52 3.10 1.62 2.340.6930.612 7.34 2.98 3.22 0.32CB4 CB3 0.35 0.51 88 12 6.3 0.014 0.9 0.35 0.32 0.32 3.22 1.01 2.360.4290.459 5.51 3.01 2.92 0.50CB3 Pond 0.93 0.58 43 15 6.3 0.014 0.9 0.93 0.84 0.84 3.22 2.69 4.570.5900.551 8.27 3.72 3.87 0.19Page 1201
12740-conveyance.xlsBARGHAUSEN CONSULTING ENGINEERS - PIPE FLOW CALCULATORusing the Rational Method & Manning FormulaKING COUNTY DESIGN FOR 100YEAR STORMJOB NAME: Storage One NOTE: ENTER DEFAULTS AND STORM DATA BEFORE BEGINNING JOB#: 12740 DEFAULTS C= 0.9 n= 0.014REVISED:5/18/2016 d=12Tc=6.3A= Contributing Area (Ac) Qd= Design Flow (cfs) COEFFICIENTS FOR THE RATIONAL METHOD "Ir"-EQUATIONC= Runoff Coefficient Qf= Full Capacity Flow (cfs)STORMAr BrTc= Time of Concentration (min) Vd= Velocity at Design Flow (fps) 2YR 1.58 0.58I= Intensity at Tc (in/hr) Vf= Velocity at Full Flow (fps) 10YR 2.44 0.64 PRECIP=4d= Diameter of Pipe (in) s= Slope of pipe (%) 25YR 2.66 0.65 Ar=2.61L= Length of Pipe (ft) n= Manning Roughness Coefficient 50YR 2.75 0.65 Br=0.63D= Water Depth at Qd (in) Tt= Travel Time at Vd (min) 100YR 2.61 0.63FROM TO A s L d Tc n C SUM A A*C SUM A*C I Qd QfQd/QfD/d D Vf Vd Tt====== ====== ====== ====== ================== ====== ====== ====== ===================== ====== ====== ====== ====== ====== ====== ====== ======CB2 CB7 0.21 0.51 35 12 6.3 0.014 0.9 0.21 0.19 0.19 3.27 0.62 2.360.2620.350 4.20 3.01 2.53 0.23CB8 CB7 0.07 0.50 20 12 6.5 0.014 0.9 0.28 0.06 0.25 3.20 0.81 2.340.3450.406 4.87 2.98 2.71 0.12CB7 CB3 0.30 0.50 62 12 6.7 0.014 0.9 0.58 0.27 0.52 3.16 1.65 2.340.7060.621 7.45 2.98 3.23 0.32CB4 CB3 0.35 0.51 88 12 6.3 0.014 0.9 0.35 0.32 0.32 3.27 1.03 2.360.4370.464 5.57 3.01 2.93 0.50CB3 Pond 0.93 0.58 43 15 6.3 0.014 0.9 0.93 0.84 0.84 3.27 2.74 4.570.6000.557 8.36 3.72 3.88 0.18Page 1202
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BACKWATER COMPUTER PROGRAM FOR PIPES
Pipe data from file:12740-1.bwp
Surcharge condition at intermediate junctions
Tailwater Elevation:397.42 feet
Discharge Range:0.69 to 2.69 Step of 0.1 [cfs]
Overflow Elevation:398.1 feet
Weir:NONE
Channel Width:3. feet
PIPE NO. 1: 43 LF - 15"CP @ 0.58% OUTLET: 393.90 INLET: 394.15 INTYP: 5
JUNC NO. 1: OVERFLOW-EL: 398.10 BEND: 90 DEG DIA/WIDTH: 4.0 Q-RATIO: 0.66
Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI
*******************************************************************************
0.69 3.29 397.44 * 0.012 0.33 0.31 3.52 3.52 3.28 3.29 0.44
0.79 3.29 397.44 * 0.012 0.35 0.33 3.52 3.52 3.28 3.29 0.48
0.89 3.29 397.44 * 0.012 0.38 0.35 3.52 3.52 3.28 3.29 0.51
0.99 3.30 397.45 * 0.012 0.40 0.37 3.52 3.52 3.28 3.30 0.54
1.09 3.31 397.46 * 0.012 0.42 0.39 3.52 3.52 3.28 3.31 0.57
1.19 3.31 397.46 * 0.012 0.44 0.41 3.52 3.52 3.28 3.31 0.60
1.29 3.32 397.47 * 0.012 0.45 0.42 3.52 3.52 3.28 3.32 0.63
1.39 3.33 397.48 * 0.012 0.47 0.44 3.52 3.52 3.29 3.33 0.66
1.49 3.34 397.49 * 0.012 0.49 0.46 3.52 3.52 3.29 3.34 0.69
1.59 3.35 397.50 * 0.012 0.50 0.47 3.52 3.52 3.29 3.35 0.72
1.69 3.36 397.51 * 0.012 0.52 0.49 3.52 3.52 3.30 3.36 0.74
1.79 3.37 397.52 * 0.012 0.54 0.50 3.52 3.52 3.30 3.37 0.77
1.89 3.38 397.53 * 0.012 0.55 0.52 3.52 3.52 3.30 3.38 0.80
1.99 3.39 397.54 * 0.012 0.57 0.53 3.52 3.52 3.30 3.39 0.83
2.09 3.41 397.56 * 0.012 0.58 0.55 3.52 3.52 3.31 3.41 0.85
2.19 3.42 397.57 * 0.012 0.60 0.56 3.52 3.52 3.31 3.42 0.88
2.29 3.43 397.58 * 0.012 0.61 0.58 3.52 3.52 3.32 3.43 0.91
2.39 3.45 397.60 * 0.012 0.62 0.59 3.52 3.52 3.32 3.45 0.93
2.49 3.46 397.61 * 0.012 0.64 0.61 3.52 3.52 3.32 3.46 0.96
2.59 3.48 397.63 * 0.012 0.65 0.62 3.52 3.52 3.33 3.48 0.99
2.69 3.49 397.64 * 0.012 0.66 0.63 3.52 3.52 3.33 3.49 1.01
2.79 3.51 397.66 * 0.012 0.68 0.65 3.52 3.52 3.34 3.51 1.04
PIPE NO. 2: 62 LF - 12"CP @ 0.50% OUTLET: 394.15 INLET: 394.46 INTYP: 5
JUNC NO. 2: OVERFLOW-EL: 398.58 BEND: 0 DEG DIA/WIDTH: 4.0 Q-RATIO: 1.66
Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI
*******************************************************************************
0.42 3.00 397.46 * 0.012 0.27 0.27 3.29 3.29 2.99 3.00 0.36
0.48 3.00 397.46 * 0.012 0.29 0.29 3.29 3.29 2.99 3.00 0.39
0.54 3.01 397.47 * 0.012 0.31 0.31 3.29 3.29 3.00 3.01 0.42
0.60 3.02 397.48 * 0.012 0.33 0.32 3.30 3.30 3.01 3.02 0.44
0.66 3.03 397.49 * 0.012 0.34 0.34 3.31 3.31 3.01 3.03 0.46
0.72 3.04 397.50 * 0.012 0.36 0.35 3.31 3.31 3.03 3.04 0.49
0.78 3.06 397.52 * 0.012 0.37 0.37 3.32 3.32 3.04 3.06 0.51
0.84 3.07 397.53 * 0.012 0.39 0.39 3.33 3.33 3.05 3.07 0.53
0.90 3.09 397.55 * 0.012 0.40 0.40 3.34 3.34 3.06 3.09 0.56
0.96 3.11 397.57 * 0.012 0.42 0.41 3.35 3.35 3.08 3.11 0.58
1.02 3.13 397.59 * 0.012 0.43 0.43 3.36 3.36 3.09 3.13 0.60
1.08 3.15 397.61 * 0.012 0.44 0.44 3.37 3.37 3.11 3.15 0.62
1.14 3.17 397.63 * 0.012 0.45 0.46 3.38 3.38 3.12 3.17 0.64
1.20 3.20 397.66 * 0.012 0.47 0.47 3.39 3.39 3.14 3.20 0.66
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1.26 3.22 397.68 * 0.012 0.48 0.48 3.41 3.41 3.16 3.22 0.68
1.32 3.25 397.71 * 0.012 0.49 0.50 3.42 3.42 3.18 3.25 0.70
1.38 3.27 397.73 * 0.012 0.50 0.51 3.43 3.43 3.20 3.27 0.72
1.44 3.30 397.76 * 0.012 0.51 0.52 3.45 3.45 3.22 3.30 0.74
1.50 3.33 397.79 * 0.012 0.52 0.53 3.46 3.46 3.25 3.33 0.76
1.56 3.36 397.82 * 0.012 0.54 0.55 3.48 3.48 3.27 3.36 0.78
1.62 3.39 397.85 * 0.012 0.55 0.56 3.49 3.49 3.29 3.39 0.80
1.68 3.42 397.88 * 0.012 0.56 0.57 3.51 3.51 3.32 3.42 0.81
PIPE NO. 3: 35 LF - 12"CP @ 0.51% OUTLET: 394.46 INLET: 394.64 INTYP: 5
Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI
*******************************************************************************
0.16 2.82 397.46 * 0.012 0.17 0.17 3.00 3.00 2.82 2.82 0.22
0.18 2.82 397.46 * 0.012 0.18 0.18 3.00 3.00 2.82 2.82 0.23
0.20 2.83 397.47 * 0.012 0.19 0.19 3.01 3.01 2.83 2.83 0.25
0.22 2.84 397.48 * 0.012 0.20 0.20 3.02 3.02 2.84 2.84 0.26
0.25 2.85 397.49 * 0.012 0.21 0.21 3.03 3.03 2.85 2.85 0.27
0.27 2.87 397.51 * 0.012 0.22 0.22 3.04 3.04 2.87 2.87 0.29
0.29 2.88 397.52 * 0.012 0.23 0.22 3.06 3.06 2.88 2.88 0.30
0.31 2.90 397.54 * 0.012 0.24 0.23 3.07 3.07 2.90 2.90 0.31
0.34 2.92 397.56 * 0.012 0.24 0.24 3.09 3.09 2.91 2.92 0.32
0.36 2.94 397.58 * 0.012 0.25 0.25 3.11 3.11 2.93 2.94 0.33
0.38 2.96 397.60 * 0.012 0.26 0.26 3.13 3.13 2.95 2.96 0.35
0.41 2.98 397.62 * 0.012 0.27 0.26 3.15 3.15 2.97 2.98 0.36
0.43 3.00 397.64 * 0.012 0.28 0.27 3.17 3.17 3.00 3.00 0.37
0.45 3.03 397.67 * 0.012 0.28 0.28 3.20 3.20 3.02 3.03 0.38
0.47 3.05 397.69 * 0.012 0.29 0.28 3.22 3.22 3.05 3.05 0.39
0.50 3.08 397.72 * 0.012 0.30 0.29 3.25 3.25 3.07 3.08 0.40
0.52 3.11 397.75 * 0.012 0.30 0.30 3.27 3.27 3.10 3.11 0.41
0.54 3.14 397.78 * 0.012 0.31 0.30 3.30 3.30 3.13 3.14 0.42
0.56 3.17 397.81 * 0.012 0.32 0.31 3.33 3.33 3.16 3.17 0.43
0.59 3.20 397.84 * 0.012 0.32 0.32 3.36 3.36 3.19 3.20 0.44
0.61 3.23 397.87 * 0.012 0.33 0.32 3.39 3.39 3.22 3.23 0.45
0.63 3.27 397.91 * 0.012 0.34 0.33 3.42 3.42 3.25 3.27 0.46
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BACKWATER COMPUTER PROGRAM FOR PIPES
Pipe data from file:12740-1.bwp
Surcharge condition at intermediate junctions
Tailwater Elevation:397.55 feet
Discharge Range:0.74 to 2.74 Step of 0.1 [cfs]
Overflow Elevation:398.1 feet
Weir:NONE
Channel Width:3. feet
PIPE NO. 1: 43 LF - 15"CP @ 0.58% OUTLET: 393.90 INLET: 394.15 INTYP: 5
JUNC NO. 1: OVERFLOW-EL: 398.10 BEND: 90 DEG DIA/WIDTH: 4.0 Q-RATIO: 0.66
Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI
*******************************************************************************
0.74 3.42 397.57 * 0.012 0.34 0.32 3.65 3.65 3.41 3.42 0.46
0.84 3.42 397.57 * 0.012 0.36 0.34 3.65 3.65 3.41 3.42 0.49
0.94 3.43 397.58 * 0.012 0.39 0.36 3.65 3.65 3.41 3.43 0.53
1.04 3.43 397.58 * 0.012 0.41 0.38 3.65 3.65 3.41 3.43 0.56
1.14 3.44 397.59 * 0.012 0.43 0.40 3.65 3.65 3.41 3.44 0.59
1.24 3.45 397.60 * 0.012 0.44 0.41 3.65 3.65 3.41 3.45 0.62
1.34 3.46 397.61 * 0.012 0.46 0.43 3.65 3.65 3.42 3.46 0.65
1.44 3.46 397.61 * 0.012 0.48 0.45 3.65 3.65 3.42 3.46 0.67
1.54 3.47 397.62 * 0.012 0.50 0.46 3.65 3.65 3.42 3.47 0.70
1.64 3.48 397.63 * 0.012 0.51 0.48 3.65 3.65 3.42 3.48 0.73
1.74 3.49 397.64 * 0.012 0.53 0.50 3.65 3.65 3.43 3.49 0.76
1.84 3.50 397.65 * 0.012 0.54 0.51 3.65 3.65 3.43 3.50 0.79
1.94 3.52 397.67 * 0.012 0.56 0.53 3.65 3.65 3.43 3.52 0.81
2.04 3.53 397.68 * 0.012 0.57 0.54 3.65 3.65 3.44 3.53 0.84
2.14 3.54 397.69 * 0.012 0.59 0.56 3.65 3.65 3.44 3.54 0.87
2.24 3.56 397.71 * 0.012 0.60 0.57 3.65 3.65 3.44 3.56 0.89
2.34 3.57 397.72 * 0.012 0.62 0.58 3.65 3.65 3.45 3.57 0.92
2.44 3.58 397.73 * 0.012 0.63 0.60 3.65 3.65 3.45 3.58 0.95
2.54 3.60 397.75 * 0.012 0.64 0.61 3.65 3.65 3.46 3.60 0.97
2.64 3.62 397.77 * 0.012 0.66 0.63 3.65 3.65 3.46 3.62 1.00
2.74 3.63 397.78 * 0.012 0.67 0.64 3.65 3.65 3.47 3.63 1.03
2.74 3.63 397.78 * 0.012 0.67 0.64 3.65 3.65 3.47 3.63 1.03
PIPE NO. 2: 62 LF - 12"CP @ 0.50% OUTLET: 394.15 INLET: 394.46 INTYP: 5
JUNC NO. 2: OVERFLOW-EL: 398.58 BEND: 0 DEG DIA/WIDTH: 4.0 Q-RATIO: 1.66
Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI
*******************************************************************************
0.45 3.14 397.60 * 0.012 0.28 0.28 3.42 3.42 3.13 3.14 0.38
0.51 3.13 397.59 * 0.012 0.30 0.30 3.42 3.42 3.12 3.13 0.40
0.57 3.14 397.60 * 0.012 0.32 0.31 3.43 3.43 3.13 3.14 0.43
0.63 3.15 397.61 * 0.012 0.33 0.33 3.43 3.43 3.14 3.15 0.45
0.69 3.17 397.63 * 0.012 0.35 0.35 3.44 3.44 3.15 3.17 0.48
0.75 3.18 397.64 * 0.012 0.37 0.36 3.45 3.45 3.16 3.18 0.50
0.81 3.20 397.66 * 0.012 0.38 0.38 3.46 3.46 3.17 3.20 0.52
0.87 3.21 397.67 * 0.012 0.40 0.39 3.46 3.46 3.19 3.21 0.54
0.93 3.23 397.69 * 0.012 0.41 0.41 3.47 3.47 3.20 3.23 0.57
0.99 3.25 397.71 * 0.012 0.42 0.42 3.48 3.48 3.21 3.25 0.59
1.05 3.27 397.73 * 0.012 0.44 0.43 3.49 3.49 3.23 3.27 0.61
1.11 3.29 397.75 * 0.012 0.45 0.45 3.50 3.50 3.25 3.29 0.63
1.17 3.31 397.77 * 0.012 0.46 0.46 3.52 3.52 3.26 3.31 0.65
1.23 3.34 397.80 * 0.012 0.47 0.48 3.53 3.53 3.28 3.34 0.67
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1.29 3.36 397.82 * 0.012 0.48 0.49 3.54 3.54 3.30 3.36 0.69
1.35 3.39 397.85 * 0.012 0.50 0.50 3.56 3.56 3.32 3.39 0.71
1.41 3.42 397.88 * 0.012 0.51 0.51 3.57 3.57 3.34 3.42 0.73
1.47 3.44 397.90 * 0.012 0.52 0.53 3.58 3.58 3.36 3.44 0.75
1.53 3.47 397.93 * 0.012 0.53 0.54 3.60 3.60 3.39 3.47 0.77
1.59 3.50 397.96 * 0.012 0.54 0.55 3.62 3.62 3.41 3.50 0.79
1.65 3.54 398.00 * 0.012 0.55 0.57 3.63 3.63 3.44 3.54 0.80
1.65 3.54 398.00 * 0.012 0.55 0.57 3.63 3.63 3.44 3.54 0.80
PIPE NO. 3: 35 LF - 12"CP @ 0.51% OUTLET: 394.46 INLET: 394.64 INTYP: 5
Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI
*******************************************************************************
0.17 2.96 397.60 * 0.012 0.17 0.17 3.14 3.14 2.96 2.96 0.22
0.19 2.95 397.59 * 0.012 0.18 0.18 3.13 3.13 2.95 2.95 0.24
0.21 2.97 397.61 * 0.012 0.19 0.19 3.14 3.14 2.96 2.97 0.25
0.24 2.98 397.62 * 0.012 0.20 0.20 3.15 3.15 2.98 2.98 0.27
0.26 2.99 397.63 * 0.012 0.21 0.21 3.17 3.17 2.99 2.99 0.28
0.28 3.01 397.65 * 0.012 0.22 0.22 3.18 3.18 3.00 3.01 0.29
0.30 3.02 397.66 * 0.012 0.23 0.23 3.20 3.20 3.02 3.02 0.31
0.33 3.04 397.68 * 0.012 0.24 0.24 3.21 3.21 3.04 3.04 0.32
0.35 3.06 397.70 * 0.012 0.25 0.24 3.23 3.23 3.05 3.06 0.33
0.37 3.08 397.72 * 0.012 0.26 0.25 3.25 3.25 3.07 3.08 0.34
0.39 3.10 397.74 * 0.012 0.26 0.26 3.27 3.27 3.09 3.10 0.35
0.42 3.12 397.76 * 0.012 0.27 0.27 3.29 3.29 3.12 3.12 0.36
0.44 3.15 397.79 * 0.012 0.28 0.27 3.31 3.31 3.14 3.15 0.37
0.46 3.17 397.81 * 0.012 0.29 0.28 3.34 3.34 3.16 3.17 0.38
0.48 3.20 397.84 * 0.012 0.29 0.29 3.36 3.36 3.19 3.20 0.39
0.51 3.22 397.86 * 0.012 0.30 0.29 3.39 3.39 3.21 3.22 0.40
0.53 3.25 397.89 * 0.012 0.31 0.30 3.42 3.42 3.24 3.25 0.41
0.55 3.28 397.92 * 0.012 0.31 0.31 3.44 3.44 3.27 3.28 0.42
0.58 3.31 397.95 * 0.012 0.32 0.31 3.47 3.47 3.30 3.31 0.43
0.60 3.35 397.99 * 0.012 0.33 0.32 3.50 3.50 3.33 3.35 0.44
0.62 3.38 398.02 * 0.012 0.33 0.33 3.54 3.54 3.37 3.38 0.45
0.62 3.38 398.02 * 0.012 0.33 0.33 3.54 3.54 3.37 3.38 0.45
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12740.008.doc
6.0 SPECIAL REPORTS AND STUDIES
A geotechnical engineering report has been prepared for this site by Geotech Consultants, Inc.
dated May 29, 2014. The report is enclosed.
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12740.008.doc
7.0 OTHER PERMITS
Other permits for this project include:
· Building Permit
· Right-of-Way Use Permit
· NPDES Permit
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12740.008.doc
8.0 CSWPPP ANALYSIS AND DESIGN
This project will utilize appropriate erosion and sediment control measures in order to protect the
site and adjacent properties. See also the Stormwater Pollution Prevention Plan (SWPPP)
prepared for this project.
1. Mark Clearing Limits – To protect adjacent properties and to reduce the area of soil
exposed to construction, the limits of construction will be clearly marked before land-
disturbing activities begin. Trees that are to be preserved, as well as all sensitive areas and
their buffers, shall be clearly delineated, both in the field and on the plans. In general, natural
vegetation and native topsoil shall be retained in an undisturbed state to the maximum extent
possible. The BMPs relevant to marking the clearing limits that will be applied for this project
include:
· Buffer Zones (BMP C102)
· High Visibility Plastic or Metal Fence (BMP C103)
Clearing Limits and Buffer Zones shall be as shown on the plans and all vegetation outside
the clearing limits shall be preserved.
2. Establish Construction Access - Construction access or activities occurring on unpaved
areas shall be minimized, yet where necessary, access points shall be stabilized to minimize
the tracking of sediment onto public roads, and wheel washing, street sweeping, and street
cleaning shall be employed to prevent sediment from entering state waters. All wash
wastewater shall be controlled on site. The specific BMPs related to establishing
construction access that will be used on this project include:
· Stabilized Construction Entrance (BMP C105)
A stabilized construction entrance shall be installed as shown on the plans.
3. Control Flow Rates – In order to protect the properties and waterways downstream of the
project site, stormwater discharges from the site will be controlled. The specific BMPs for
flow control that shall be used on this project include:
· Temporary Sediment Pond (BMP C241)
The final pond will be constructed during the TESC phase and will be used as a sediment
pond during construction. The pond will have a sediment pond riser with an orifice to control
the flows being discharged offsite.
4. Install Sediment Controls - All stormwater runoff from disturbed areas shall pass through an
appropriate sediment removal BMP before leaving the construction site or prior to being
discharged to an infiltration facility. The specific BMPs to be used for controlling sediment on
this project include:
· Silt Fence (BMP C233)
· Materials on Hand (BMP C150) may also be applicable
Silt fence is to be installed along the perimeter of the project site, wherever the onside grades
will be higher than the adjacent properties. Locations of silt fence installation are marked on
the plans.
12740.008.doc
Material shall be contained onsite using good housekeeping practices to reduce the chance
that any construction materials or chemicals be introduced to surface water runoff.
5. Stabilize Soils - Exposed and unworked soils shall be stabilized with the application of
effective BMPs to prevent erosion throughout the life of the project. The specific BMPs for
soil stabilization that shall be used on this project include:
· Temporary and Permanent Seeding (BMP C120)
· Nets and Blankets (BMP C122)
· Topsoiling (BMP C125)
· Dust Control (BMP C140)
· Early application of gravel base on areas to be paved
All areas disturbed by construction activities shall be hydro-seeded upon completion of
grading activities or if they will be unworked for more than 2 days in the wet season or 7 days
in the dry season. Jute mesh maybe required to stabilize the 2:1 slopes adjacent to the
pond.
6. Protect Slopes – All cut and fill slopes will be designed, constructed, and protected in a
manner than minimizes erosion. The following specific BMPs will be used to protect slopes
for this project:
· Temporary and Permanent Seeding (BMP C120)
· Interceptor Dike and Swale (BMP C200)
· Check Dams (BMP C207)
Steep slopes will be protected from erosion by not directing runoff toward them. When
necessary, such as where the interceptor ditches enter the stormwater ponds, riprap is to be
used to limit the bank erosion.
7. Protect Drain Inlets – All storm drain inlets and culverts made operable during construction
shall be protected to prevent unfiltered or untreated water from entering the drainage
conveyance system. However, the first priority is to keep all access roads clean of sediment
and keep street wash water separate from entering storm drains until treatment can be
provided. Storm Drain Inlet Protection (BMP C220) will be implemented for all drainage inlets
and culverts that could potentially be impacted by sediment-laden runoff on and near the
project site. The following inlet protection measures may need to be applied on this project:
· Catch Basin Filters
Existing catch basins will be protected from sediment-laden runoff by a geotextile fabric catch
basin insert. These insert shall be installed on the existing catch basins in NE 4th Street as
well as any newly constructed catch basins onsite. Please refer to the TESC plans for
placement of the catch basin inserts and the insert detail.
8. Stabilize Channels and Outlets – Where site runoff is to be conveyed in channels, or
discharged to a stream or some other natural drainage point, efforts will be taken to prevent
downstream erosion. The specific BMPs for channel and outlet stabilization that shall be
used on this project include:
12740.008.doc
· Outlet Protection (BMP C209)
Runoff from the graded site is directed to temporary ‘v’-ditches with rock check dams. The
checks will slow the velocity of the runoff in the channel and reduce the amount of sediment
transported. Where there is an elevation change in the ‘v’-ditches, riprap will be installed to
protect the channel from erosion. Riprap will also be used to protect the inlets of the bypass
system and the bank on the sediment pond where the ditches enter.
9. Control Pollutants – All pollutants, including waste materials and demolition debris, that
occur onsite shall be handled and disposed of in a manner that does not cause contamination
of stormwater. Good housekeeping and preventative measures will be taken to ensure that
the site will be kept clean, well-organized, and free of debris.
10. Control Dewatering– All dewatering water from open cut excavation, tunneling, foundation
work, trench, or underground vaults shall be discharged into a controlled conveyance system
prior to discharge to a sediment trap or sediment pond. Channels will be stabilized, per
Element #8. Clean, nonturbid dewatering water will not be routed through stormwater
sediment ponds, and will be discharged to systems tributary to the receiving waters of the
State in a manner that does not cause erosion, flooding, or a violation of State water quality
standards in the receiving water. Highly turbid dewatering water from soils known or
suspected to be contaminated, or from use of construction equipment, will require additional
monitoring and treatment as required for the specific pollutants based on the receiving waters
into which the discharge is occurring. Such monitoring is the responsibility of the contractor.
However, the dewatering of soils known to be free of contamination will trigger BMPs to trap
sediment and reduce turbidity. At a minimum, geotextile fabric socks/bags/cells will be used
to filter this material. Other BMPs to be used for sediment trapping and turbidity reduction
include the following:
· Concrete Handling (BMP C151)
· Temporary Sediment Pond (BMP C241)
11. Maintain BMPs – All temporary and permanent erosion and sediment control BMPs shall be
maintained and repaired as needed to assure continued performance of their intended
function. Maintenance and repair shall be conducted in accordance with each particular
BMP’s specifications. Visual monitoring of the BMPs will be conducted at least once every
calendar week and within 24 hours of any rainfall event that causes a discharge from the site.
If the site becomes inactive, and is temporarily stabilized, the inspection frequency will be
reduced to once every month.
All temporary erosion and sediment control BMPs shall be removed within 30 days after the
final site stabilization is achieved or after the temporary BMPs are no longer needed.
Trapped sediment shall be removed or stabilized on site. Disturbed soil resulting from
removal of BMPs or vegetation shall be permanently stabilized.
12. Manage Project - Project management will incorporate the key components listed below:
· Phasing of Construction
The construction project is being phased to the extent practicable in order to prevent
soil erosion, and, to the maximum extent possible, the transport of sediment from the
site during construction.
12740.008.doc
Re-vegetation of exposed areas and maintenance of that vegetation shall be an
integral part of the clearing activities during each phase of construction, per the
Scheduling BMP (C 162).
· Seasonal Work Limitations
From October 1 through April 30, clearing, grading, and other soil disturbing
activities shall only be permitted if shown to the satisfaction of the local permitting
authority that silt-laden runoff will be prevented from leaving the site through a
combination of the following:
Site conditions including existing vegetative coverage, slope, soil type, and proximity
to receiving waters; and
Limitations on activities and the extent of disturbed areas; and
Proposed erosion and sediment control measures.
Based on the information provided and/or local weather conditions, the local
permitting authority may expand or restrict the seasonal limitation on site disturbance.
The following activities are exempt from the seasonal clearing and grading
limitations:
o Routine maintenance and necessary repair of erosion and sediment control
BMPs;
o Routine maintenance of public facilities or existing utility structures that do
not expose the soil or result in the removal of the vegetative cover to soil;
and
o Activities where there is 100 percent infiltration of surface water runoff within
the site in approved and installed erosion and sediment control facilities.
· Coordination with Utilities and Other Jurisdictions
Care has been taken to coordinate with utilities, other construction projects, and the
local jurisdiction in preparing this SWPPP and scheduling the construction work.
· Inspection and Monitoring
o All BMPs shall be inspected, maintained, and repaired as needed to assure
continued performance of their intended function. Site inspections shall be
conducted by a person who is knowledgeable in the principles and practices of
erosion and sediment control. This person has the necessary skills to:
Assess the site conditions and construction activities that could impact the
quality of stormwater, and
Assess the effectiveness of erosion and sediment control measures used to
control the quality of stormwater discharges.
o A Certified Erosion and Sediment Control Lead shall be on-site or on-call at all
times.
12740.008.doc
o Whenever inspection and/or monitoring reveals that the BMPs identified in this
SWPPP are inadequate, due to the actual discharge of or potential to discharge
a significant amount of any pollutant, appropriate BMPs or design changes shall
be implemented as soon as possible.
· Maintaining an Updated Construction SWPPP
o This SWPPP shall be retained on-site or within reasonable access to the site.
o The SWPPP shall be modified whenever there is a change in the design,
construction, operation, or maintenance at the construction site that has, or could
have, a significant effect on the discharge of pollutants to waters of the state.
o The SWPPP shall be modified if, during inspections or investigations conducted
by the owner/operator, or the applicable local or state regulatory authority, it is
determined that the SWPPP is ineffective in eliminating or significantly
minimizing pollutants in stormwater discharges from the site. The SWPPP shall
be modified as necessary to include additional or modified BMPs designed to
correct problems identified. Revisions to the SWPPP shall be completed within
seven (7) days following the inspection.
Because this site is greater than 1 acre, a General Permit from the Department of Ecology is
required. The NPDES was received from the DOE on June 6, 2016 and is included in this
section.
STATE OF WASHINGTON
DEPARTMENT OF ECOLOGY
PO Box 47600 • Olympia, WA 98504-7600 • 360-407-6000
711 for Washington Relay Service • Persons with a speech disability can call 877-833-6341
June 6,2016
Travis Ameche
Urban Development & Construction LLC
918 S Horton St
Seattle, WA 98134-1952
RE: Coverage under the Construction Stormwater General Permit
Permit number: W4R304097
Site Name: Storage One on 4th Expansion
Location: NE 4111 Street, between Duvall Ave NE & Field Place NE
Renton, WA County: King
Disturbed Acres: 1.48
Dear Mr. Ameche:
The Washington State Department of Ecology (Ecology) received your Notice of Intent for coverage
under Ecology's Construction Stormwater General Permit (permit). This is your permit coverage
letter. Your permit coverage is effective on June 6, 2016. Please retain this permit coverage letter
with your permit (enclosed), stormwater pollution prevention plan (SVVPPP), and site log book
These materials are the official record of permit coverage for your site.
Please take time to read the entire permit and contact Ecology if you have any questions.
Appeal Process
You have a right to appeal coverage under the general permit to the Pollution Control Hearing Board
(PCHB) within 30 days of the date of receipt of this letter. This appeal is limited to the general
permit's applicability or non-applicability to a specific discharger. The appeal process is governed by
chapter 43.21B RCW and chapter 371-08 WAC. "Date of receipt" is defined in RCW 43.21B.001(2).
To appeal, you must do the following within 30 days of the date of receipt of this letter:
• File your appeal and a copy of the permit cover page with the PCHB (see addresses below).
Filing means actual receipt by the PCHB during regular business hours.
• Serve a copy of your appeal and the permit cover page on Ecology in paper form -
by mail or in person (see addresses below). E-mail is not accepted.
Travis Ameche
June 6,2016
Page 2
You must also comply with other applicable requirements in chapter 43.21B RCW and chapter 371-
08 WAC.
Address and Location Information:
Street Addresses:
Department of Ecology
Attn: Appeals Processing Desk
300 Desmond Drive SE
Lacey, WA 98503
Pollution Control Hearings Board (PCHB)
1111 Israel Road SW, Suite 301
Tumwater, WA 98501
Mailing Addresses:
Department of Ecology
Attn: Appeals Processing Desk
PO Box 47608
Olympia, WA 98504-7608
Pollution Control Hearings Board
PO Box 40903
Olympia, WA 98504-0903
Electronic Discharge Monitoring Reports (WQWebDMR)
This permit requires that Permittees submit monthly discharge monitoring reports (DMRs) electronically
using Ecology's secure online system, WQWebDMR. To sign up for WQWebDMR go to:
www.ecy.wa.gov/programs/wq/permits/paris/webdmr.html. If you have questions, contact the portal staff
at (360) 407-7097 (Olympia area), or (800) 633-6193/option 3, or email WQWebPortal@ecy.wa.gov.
Ecology Field Inspector Assistance
If you have questions regarding stormwater management at your construction site, please contact
Tracie Walters of Ecology's Northwest Regional Office in Bellevue at tracie.walters@ecy.wa.gov or
(425) 649-4484.
Questions or Additional Information
Ecology is committed to providing assistance. Please review our web page at:
www.ecy.wa.gov/programs/wq/stormwater/construction. If you have questions about the
construction stormwater general permit, please contact Melinda Wilson at
melinda.wilson@ecy.wa.gov or (360) 407-6556.
Sincerely,
Bill Moore, P.E., Manager
Program Development Services Section
Water Quality Program
Enclosure
238
12740.008.doc
9.0 BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT
Bond quantities are included in the following pages.
239
Site Improvement Bond Quantity WorksheetWeb date: 12/02/2008Department of Development & Environmental Services900 Oakesdale Avenue SouthwestRenton, Washington 98057-5212206-296-6600 TTY 206-296-7217Project Name: Date: Location: Project No.: Activity No.: Note: All prices include labor, equipment, materials, overhead and Clearing greater than or equal to 5,000 board feet of timber? profit. Prices are from RS Means data adjusted for the Seattle area or from local sources if not included in the RS Means database._____________yes __________________no If yes, Forest Practice Permit Number: (RCW 76.09)Page 1 of 9Storage One on 4th Expansion4815 NE 4th Street, Renton WA For alternate formats, call 206-296-6600. __________________5/23/201612740 - Bond Quantity Worksheet.xlsUnit prices updated: 02/12/02 Version: 11/26/2008Report Date: 5/23/2016240
Site Improvement Bond Quantity WorksheetWeb date: 12/02/2008Unit# ofReference #PriceUnitQuantity ApplicationsCostEROSION/SEDIMENT CONTROLNumberBackfill & compaction-embankmentESC-15.62$ CYCheck dams, 4" minus rockESC-2SWDM 5.4.6.3 67.51$ EachCrushed surfacing 1 1/4" minusESC-3WSDOT 9-03.9(3) 85.45$ CYDitchingESC-48.08$ CYExcavation-bulkESC-51.50$ CYFence, siltESC-6SWDM 5.4.3.1 1.38$ LF 1040 11435Fence, Temporary (NGPE)ESC-71.38$ LFHydroseedingESC-8SWDM 5.4.2.4 0.59$ SYJute MeshESC-9SWDM 5.4.2.2 1.45$ SYMulch, by hand, straw, 3" deepESC-10SWDM 5.4.2.1 2.01$ SYMulch, by machine, straw, 2" deepESC-11SWDM 5.4.2.1 0.53$ SYPiping, temporary, CPP, 6"ESC-1210.70$ LFPiping, temporary, CPP, 8"ESC-1316.10$ LFPiping, temporary, CPP, 12"ESC-1420.70$ LFPlastic covering, 6mm thick, sandbaggedESC-15SWDM 5.4.2.3 2.30$ SYRip Rap, machine placed; slopesESC-16WSDOT 9-13.1(2) 39.08$ CYRock Construction Entrance, 50'x15'x1'ESC-17SWDM 5.4.4.1 1,464.34$ EachRock Construction Entrance, 100'x15'x1'ESC-18SWDM 5.4.4.1 2,928.68$ Each 1 12929Sediment pond riser assemblyESC-19SWDM 5.4.5.2 1,949.38$ Each 1 11949Sediment trap, 5' high berm ESC-20SWDM 5.4.5.1 17.91$ LFSed. trap, 5' high, riprapped spillway berm section ESC-21SWDM 5.4.5.1 68.54$ LFSeeding, by handESC-22SWDM 5.4.2.4 0.51$ SYSodding, 1" deep, level groundESC-23SWDM 5.4.2.5 6.03$ SYSodding, 1" deep, sloped groundESC-24SWDM 5.4.2.5 7.45$ SYTESC SupervisorESC-2574.75$ HR 40 12990Water truck, dust controlESC-26SWDM 5.4.7 97.75$ HRWRITE-IN-ITEMS **** (see page 9)EachESC SUBTOTAL:9,303.26$ 30% CONTINGENCY & MOBILIZATION:2,790.98$ ESC TOTAL:12,094.24$ COLUMN:APage 2 of 912740 - Bond Quantity Worksheet.xlsUnit prices updated: 02/12/02 Version: 11/26/2008Report Date: 5/23/2016241
Site Improvement Bond Quantity WorksheetWeb date: 12/02/2008Existing Future Public PrivateRight-of-Way Road Improvements Improvements & Drainage FacilitiesQuant.Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Complete CostGENERAL ITEMSNo.Backfill & Compaction- embankment GI - 1 5.62$ CYBackfill & Compaction- trench GI - 2 8.53$ CYClear/Remove Brush, by hand GI - 3 0.36$ SYClearing/Grubbing/Tree Removal GI - 4 8,876.16$ AcreExcavation - bulk GI - 5 1.50$ CY1800 2,700.00Excavation - Trench GI - 6 4.06$ CYFencing, cedar, 6' high GI - 7 18.55$ LFFencing, chain link, vinyl coated, 6' high GI - 8 13.44$ LF410 5,510.40Fencing, chain link, gate, vinyl coated, 20' GI - 9 1,271.81$ Each1 1,271.81Fencing, split rail, 3' high GI - 10 12.12$ LFFill & compact - common barrow GI - 11 22.57$ CYFill & compact - gravel base GI - 12 25.48$ CYFill & compact - screened topsoil GI - 13 37.85$ CYGabion, 12" deep, stone filled mesh GI - 14 54.31$ SYGabion, 18" deep, stone filled mesh GI - 15 74.85$ SYGabion, 36" deep, stone filled mesh GI - 16 132.48$ SYGrading, fine, by hand GI - 17 2.02$ SYGrading, fine, with grader GI - 18 0.95$ SY7116 6,760.20Monuments, 3' long GI - 19 135.13$ EachSensitive Areas Sign GI - 20 2.88$ EachSodding, 1" deep, sloped ground GI - 21 7.46$ SYSurveying, line & grade GI - 22 788.26$ DaySurveying, lot location/lines GI - 23 1,556.64$ AcreTraffic control crew ( 2 flaggers ) GI - 24 85.18$ HRTrail, 4" chipped wood GI - 25 7.59$ SYTrail, 4" crushed cinder GI - 26 8.33$ SYTrail, 4" top course GI - 27 8.19$ SYWall, retaining, concrete GI - 28 44.16$ SFWall, rockery GI - 29 9.49$ SF640 6,073.60Page 3 of 9SUBTOTAL22,316.01Quantity Completed (Bond Reduction)**KCC 27A authorizes only one bond reduction.12740 - Bond Quantity Worksheet.xlsUnit prices updated: 02/12/02Version: 11/26/08Report Date: 5/23/2016242
Site Improvement Bond Quantity WorksheetWeb date: 12/02/2008Existing Future Public PrivateBond Reduction*Right-of-way Road Improvements Improvements & Drainage FacilitiesQuant.Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Complete CostROAD IMPROVEMENTNo.AC Grinding, 4' wide machine < 1000sy RI - 1 28.00$ SYAC Grinding, 4' wide machine 1000-2000syRI - 2 15.00$ SYAC Grinding, 4' wide machine > 2000sy RI - 3 7.00$ SYAC Removal/Disposal/Repair RI - 4 67.50$ SYBarricade, type I RI - 5 30.03$ LFBarricade, type III ( Permanent ) RI - 6 45.05$ LFCurb & Gutter, rolled RI - 7 17.00$ LFCurb & Gutter, vertical RI - 8 12.50$ LF260 3,250.00Curb and Gutter, demolition and disposalRI - 9 18.00$ LF260 4,680.00Curb, extruded asphalt RI - 10 5.50$ LFCurb, extruded concrete RI - 11 7.00$ LF770 5,390.00Sawcut, asphalt, 3" depth RI - 12 1.85$ LFSawcut, concrete, per 1" depth RI - 13 1.69$ LF330 557.70Sealant, asphalt RI - 14 1.25$ LF330 412.50Shoulder, AC, ( see AC road unit price )RI - 15 -$ SYShoulder, gravel, 4" thick RI - 16 15.00$ SYSidewalk, 4" thick RI - 17 35.00$ SY1322 46,270.00 2150 75,250.00Sidewalk, 4" thick, demolition and disposalRI - 18 29.50$ SYSidewalk, 5" thick RI - 19 38.50$ SYSidewalk, 5" thick, demolition and disposalRI - 20 37.50$ SYSign, handicap RI - 21 85.28$ Each1 85.28Striping, per stall RI - 22 5.82$ Each21 122.22Striping, thermoplastic, ( for crosswalk ) RI - 23 2.38$ SFStriping, 4" reflectorized line RI - 24 0.25$ LFPage 4 of 9SUBTOTAL 55,170.20 80,847.50*KCC 27A authorizes only one bond reduction.12740 - Bond Quantity Worksheet.xlsUnit prices updated: 02/12/02Version: 11/26/08Report Date: 5/23/2016243
Site Improvement Bond Quantity WorksheetWeb date: 12/02/2008Existing Future Public PrivateBond Reduction*Right-of-way Road Improvements Improvements & Drainage FacilitiesQuant.Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Complete CostROAD SURFACING (4" Rock = 2.5 base & 1.5" top course) For '93 KCRS ( 6.5" Rock= 5" base & 1.5" top course)For KCRS '93, (additional 2.5" base) add:RS - 1 3.60$ SY1050 3,780.00AC Overlay, 1.5" AC RS - 2 11.25$ SYAC Overlay, 2" AC RS - 3 15.00$ SYAC Road, 2", 4" rock, First 2500 SY RS - 4 21.00$ SYAC Road, 2", 4" rock, Qty. over 2500SY RS - 5 19.00$ SYAC Road, 3", 4" rock, First 2500 SY RS - 6 23.30$ SY1050 24,465.00AC Road, 3", 4" rock, Qty. over 2500 SY RS - 7 21.00$ SYAC Road, 5", First 2500 SY RS - 8 27.60$ SYAC Road, 5", Qty. Over 2500 SY RS - 9 25.00$ SYAC Road, 6", First 2500 SYRS - 1033.10$ SY115 3,806.50AC Road, 6", Qty. Over 2500 SYRS - 1130.00$ SYAsphalt Treated Base, 4" thickRS - 1220.00$ SYGravel Road, 4" rock, First 2500 SYRS - 1315.00$ SYGravel Road, 4" rock, Qty. over 2500 SYRS - 148.50$ SYPCC Road, 5", no base, over 2500 SYRS - 1527.00$ SYPCC Road, 6", no base, over 2500 SYRS - 1625.50$ SYThickened EdgeRS - 178.60$ LFPage 5 of 9SUBTOTAL3,806.50 28,245.00*KCC 27A authorizes only one bond reduction.12740 - Bond Quantity Worksheet.xlsUnit prices updated: 02/12/02Version: 11/26/08Report Date: 5/23/2016244
Site Improvement Bond Quantity WorksheetWeb date: 12/02/2008Existing Future Public PrivateBond Reduction*Right-of-way Road Improvements Improvements & Drainage FacilitiesQuant.Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Complete CostDRAINAGE (CPP = Corrugated Plastic Pipe, N12 or Equivalent) For Culvert prices, Average of 4' cover was assumed. Assume perforated PVC is same price as solid pipe.Access Road, R/D D - 1 21.00$ SY177 3,717.00Bollards - fixed D - 2 240.74$ EachBollards - removable D - 3 452.34$ Each* (CBs include frame and lid)CB Type I D - 4 1,257.64$ EachCB Type IL D - 5 1,433.59$ Each4 5,734.36CB Type II, 48" diameter D - 6 2,033.57$ Each2 4,067.14 for additional depth over 4' D - 7 436.52$ FTCB Type II, 54" diameter D - 8 2,192.54$ Each1 2,192.54 for additional depth over 4' D - 9 486.53$ FTCB Type II, 60" diameter D - 10 2,351.52$ Each for additional depth over 4' D - 11 536.54$ FTCB Type II, 72" diameter D - 12 3,212.64$ Each for additional depth over 4' D - 13 692.21$ FTThrough-curb Inlet Framework (Add) D - 14 366.09$ EachCleanout, PVC, 4" D - 15 130.55$ EachCleanout, PVC, 6" D - 16 174.90$ Each3 524.70Cleanout, PVC, 8" D - 17 224.19$ EachCulvert, PVC, 4" D - 18 8.64$ LFCulvert, PVC, 6" D - 19 12.60$ LF84 1,058.40Culvert, PVC, 8" D - 20 13.33$ LFCulvert, PVC, 12" D - 21 21.77$ LFCulvert, CMP, 8" D - 22 17.25$ LFCulvert, CMP, 12" D - 23 26.45$ LFCulvert, CMP, 15" D - 24 32.73$ LFCulvert, CMP, 18" D - 25 37.74$ LFCulvert, CMP, 24" D - 26 53.33$ LFCulvert, CMP, 30" D - 27 71.45$ LFCulvert, CMP, 36" D - 28 112.11$ LFCulvert, CMP, 48" D - 29 140.83$ LFCulvert, CMP, 60" D - 30 235.45$ LFCulvert, CMP, 72" D - 31 302.58$ LFPage 6 of 9SUBTOTAL 17,294.14*KCC 27A authorizes only one bond reduction.12740 - Bond Quantity Worksheet.xlsUnit prices updated: 02/12/02Version: 11/26/08Report Date: 5/23/2016245
Site Improvement Bond Quantity WorksheetWeb date: 12/02/2008Existing Future Public PrivateBond Reduction*Right-of-way Road Improvements ImprovementsDRAINAGE CONTINUED & Drainage FacilitiesQuant.No. Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Complete CostCulvert, Concrete, 8" D - 32 21.02$ LFCulvert, Concrete, 12" D - 33 30.05$ LFCulvert, Concrete, 15" D - 34 37.34$ LFCulvert, Concrete, 18" D - 35 44.51$ LFCulvert, Concrete, 24" D - 36 61.07$ LFCulvert, Concrete, 30" D - 37 104.18$ LFCulvert, Concrete, 36" D - 38 137.63$ LFCulvert, Concrete, 42" D - 39 158.42$ LFCulvert, Concrete, 48" D - 40 175.94$ LFCulvert, CPP, 6" D - 41 10.70$ LF400 4280Culvert, CPP, 8" D - 42 16.10$ LFCulvert, CPP, 12" D - 43 20.70$ LF203 4202.1Culvert, CPP, 15" D - 44 23.00$ LF45 1035Culvert, CPP, 18" D - 45 27.60$ LFCulvert, CPP, 24" D - 46 36.80$ LFCulvert, CPP, 30" D - 47 48.30$ LFCulvert, CPP, 36" D - 48 55.20$ LFDitching D - 49 8.08$ CYFlow Dispersal Trench (1,436 base+) D - 50 25.99$ LFFrench Drain (3' depth) D - 51 22.60$ LFGeotextile, laid in trench, polypropylene D - 52 2.40$ SYInfiltration pond testing D - 53 74.75$ HRMid-tank Access Riser, 48" dia, 6' deep D - 54 1,605.40$ EachPond Overflow Spillway D - 55 14.01$ SYRestrictor/Oil Separator, 12" D - 56 1,045.19$ EachRestrictor/Oil Separator, 15" D - 57 1,095.56$ EachRestrictor/Oil Separator, 18" D - 58 1,146.16$ EachRiprap, placed D - 59 39.08$ CY10 390.8Tank End Reducer (36" diameter) D - 60 1,000.50$ EachTrash Rack, 12" D - 61 211.97$ Each1 211.97Trash Rack, 15" D - 62 237.27$ EachTrash Rack, 18" D - 63 268.89$ EachTrash Rack, 21" D - 64 306.84$ EachPage 7 of 9SUBTOTAL10119.87*KCC 27A authorizes only one bond reduction.12740 - Bond Quantity Worksheet.xlsUnit prices updated: 02/12/02Version: 11/26/08Report Date: 5/23/2016246
Site Improvement Bond Quantity WorksheetWeb date: 12/02/2008Existing Future Public PrivateBond Reduction*Right-of-way Road Improvements Improvements & Drainage FacilitiesQuant.Unit Price Unit Quant. Price Quant. Cost Quant. Cost Complete CostPARKING LOT SURFACINGNo.2" AC, 2" top course rock & 4" borrow PL - 1 21.00$ SY2" AC, 1.5" top course & 2.5" base coursePL - 2 28.00$ SY4" select borrow PL - 3 4.55$ SY1.5" top course rock & 2.5" base course PL - 4 11.41$ SYUTILITY POLES & STREET LIGHTINGUtility pole relocation costs must be accompanied by Franchise Utility's Cost StatementUtility Pole(s) Relocation UP-11 10,000.00Street Light Poles w/Luminaires UP-2 8,000.00$ Each2 16,000.00WRITE-IN-ITEMS(Such as detention/water quality vaults.)No.Modular Wetland System WI - 1 40,000.000$ Each1 40,000.00Modular Grid Pavement WI - 2 5.00$ SF2700 13,500.00Permeable Pavement WI - 3 40.00$ SY250 10,000.00WI - 4 LFWI - 5 FTWI - 6WI - 7WI - 8WI - 9WI - 10SUBTOTAL 26,000.00 63,500.00SUBTOTAL (SUM ALL PAGES):84,976.70 222,322.5230% CONTINGENCY & MOBILIZATION:25,493.01 66,696.76 GRANDTOTAL: 110,469.71 289,019.28COLUMN: B C D EPage 8 of 9Lump Sum*KCC 27A authorizes only one bond reduction.12740 - Bond Quantity Worksheet.xlsUnit prices updated: 02/12/02Version: 11/26/08Report Date: 5/23/2016247
Site Improvement Bond Quantity WorksheetWeb date: 12/02/2008Original bond computations prepared by:Name:Date:PE Registration Number:Tel. #:Firm Name:Address:Project No: Stabilization/Erosion Sediment Control (ESC) (A)Existing Right-of-Way Improvements (B)Future Public Road Improvements & Drainage Facilities(C)Private Improvements (D)Calculated Quantity Completed(E)Total Right-of Way and/or Site Restoration Bond*/** (A+B)(First $7,500 of bond* shall be cash.)Performance Bond* Amount (A+B+C+D) = TOTAL (T)T x 0.30 ORMinimum bond* amount is $1000.Reduced Performance Bond* Total *** Use larger of Tx30% or (T-E)Maintenance/Defect Bond* TotalNAME OF PERSON PREPARING BOND* REDUCTION:Date:* NOTE:The word "bond" as used in this document means any financial guarantee acceptable to King County.** NOTE: KCC 27A authorizes right of way and site restoration bonds to be combined when both are required. The restoration requirement shall include the total cost for all TESC as a minimum, not a maximum. In addition, corrective work, both on- and off-site needs to be included. Quantities shall reflect worse case scenarios not just minimum requirements. For example, if a salmonid stream may be damaged, some estimated costs for restoration needs to be reflected in this amount. The 30% contingency and mobilization costs are computed in this quantity.*** NOTE: Per KCC 27A, total bond amounts remaining after reduction shall not be less than 30% of the original amount (T) or as revised by major design changes.SURETY BOND RIDER NOTE: If a bond rider is used, minimum additional performance bond shall be(C+D)-EREQUIRED BOND* AMOUNTS ARE SUBJECT TO REVIEW AND MODIFICATION BY DDES123,475.0$ (B+C) x 0.25 =12,094.2$ 289,019.3$ 411,583.2$ -$ 9/29/2015425-251-6222ROAD IMPROVEMENTS & DRAINAGE FACILITIES FINANCIAL GUARANTEE REQUIREMENTSPUBLIC ROAD & DRAINAGE MAINTENANCE/DEFECT BOND*Brandon ChaisyBarghausen Consulting Engineers18215 72nd Avenue South, Kent WA 98032PERFORMANCE BOND*AMOUNT47626BOND* AMOUNT REQUIRED AT RECORDING ORTEMPORARY OCCUPANCY ***399,489.0$ 27,617.4$ 411,583.2$ 12,094.2$ (T-E)-$ 110,469.7$ Page 9 of 912740 - Bond Quantity Worksheet.xlsCheck out the DDES Web site at www.kingcounty.gov/permitsUnit prices updated: 02/12/02Version: 11/26/08Report Date: 5/23/2016248
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10.0 OPERATION AND MAINTENANCE MANUAL
An Operation and Maintenance Manual is included in this section.
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OPERATIONS AND MAINTENANCE MANUAL
Renton Self Storage
N.E. 4th Street
Renton, Washington
Prepared for:
Jackson|Main Architects
311 1st Avenue South, Suite 300
Seattle, WA 98104
May 18, 2016
Our Job No. 12740
18215 72ND AVENUE SOUTH KENT, WA 98032 (425) 251-6222 (425) 251-8782 FAX
BRANCH OFFICES ¨ TUMWATER, WA ¨ LONG BEACH, CA ¨ ROSEVILLE, CA ¨ SAN DIEGO, CA
www.barghausen.com
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12740.006.doc
TABLE OF CONTENTS
1.0 INTRODUCTION/GENERAL INFORMATION
EXHIBIT A MAINTENANCE GUIDELINES
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1.0 INTRODUCTION/GENERAL INFORMATION
Catch basins are located on the Renton Self Storage site that collect runoff from the project site
and route that runoff through conveyance piping to the southwest corner of the site where runoff
enters a detention pond which provides flow control for the new land covers on the project site.
Level 2 Flow Control is the required means of providing Flow Control for this project. Water
quality treatment will be provided in a modular wetland to meet the City of Renton’s Enhanced
Basic Water Quality.
The release mechanism from the detention pond is a control structure located on the east side of
the pond, which has a riser pipe inside of it that releases runoff at a slow rate and tends to back
up water in the pond during peak storm events. The release to the downstream drainage course
is also through the modular wetland, to the existing wetland onsite.
All facilities on the project site should be maintained on a regular basis of at least twice a year at
an interval of every six months. Should vegetation become sparse or should it die out, then it
should be replaced around the site to match what the design conditions of the site were when the
site was initially constructed.
The following pages of this report delineate the requirements for flow control, conveyance, and
water quality facilities maintenance. Please refer to these documents when performing your
maintenance on the project site.
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GENERAL PUMP MAINTENAINCE GUIDELINES
The storm water pump(s) shall be inspected per the manufacturer's operation and maintenance
manual. Listed below are general maintenance guidelines for storm water pumps.
1) Inspect cables and cable entry for damage and/or leaks
2) Check motor insulation.
3) Check external parts (screws, bolts and nuts are tight)
4) Check seal chamber oil
5) Check impeller for wear or damage
6) Inspect floats and switches and test that the pump(s) are starting and stopping at the set
elevations
7) Operate pumps and test the operating release rate(s) to ensure the pump(s) are
functioning properly
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Maintenance Guidelines for
Modular Wetland System - Linear
Maintenance Summary
o Remove Trash from Screening Device – average maintenance interval is 6 to 12 months.
(5 minute average service time).
o Remove Sediment from Separation Chamber – average maintenance interval is 12 to 24 months.
(10 minute average service time).
o Replace Cartridge Filter Media – average maintenance interval 12 to 24 months.
(10-15 minute per cartridge average service time).
o Replace Drain Down Filter Media – average maintenance interval is 12 to 24 months.
(5 minute average service time).
o Trim Vegetation – average maintenance interval is 6 to 12 months.
(Service time varies).
System Diagram
Access to screening device, separation
chamber and cartridge filter
Access to drain
down filter
Pre-Treatment
Chamber
Biofiltration Chamber
Discharge
Chamber
Outflow
Pipe
Inflow Pipe
(optional)
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Maintenance Procedures
Screening Device
1. Remove grate or manhole cover to gain access to the screening device in the Pre-
Treatment Chamber. Vault type units do not have screening device. Maintenance
can be performed without entry.
2. Remove all pollutants collected by the screening device. Removal can be done
manually or with the use of a vacuum truck. The hose of the vacuum truck will not
damage the screening device.
3. Screening device can easily be removed from the Pre-Treatment Chamber to gain
access to separation chamber and media filters below. Replace grate or manhole
cover when completed.
Separation Chamber
1. Perform maintenance procedures of screening device listed above before
maintaining the separation chamber.
2. With a pressure washer spray down pollutants accumulated on walls and cartridge
filters.
3. Vacuum out Separation Chamber and remove all accumulated pollutants. Replace
screening device, grate or manhole cover when completed.
Cartridge Filters
1. Perform maintenance procedures on screening device and separation chamber
before maintaining cartridge filters.
2. Enter separation chamber.
3. Unscrew the two bolts holding the lid on each cartridge filter and remove lid.
4. Remove each of 4 to 8 media cages holding the media in place.
5. Spray down the cartridge filter to remove any accumulated pollutants.
6. Vacuum out old media and accumulated pollutants.
7. Reinstall media cages and fill with new media from manufacturer or outside
supplier. Manufacturer will provide specification of media and sources to purchase.
8. Replace the lid and tighten down bolts. Replace screening device, grate or
manhole cover when completed.
Drain Down Filter
1. Remove hatch or manhole cover over discharge chamber and enter chamber.
2. Unlock and lift drain down filter housing and remove old media block. Replace with
new media block. Lower drain down filter housing and lock into place.
3. Exit chamber and replace hatch or manhole cover.
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Maintenance Notes
1. Following maintenance and/or inspection, it is recommended the maintenance
operator prepare a maintenance/inspection record. The record should include any
maintenance activities performed, amount and description of debris collected, and
condition of the system and its various filter mechanisms.
2. The owner should keep maintenance/inspection record(s) for a minimum of five
years from the date of maintenance. These records should be made available to
the governing municipality for inspection upon request at any time.
3. Transport all debris, trash, organics and sediments to approved facility for disposal
in accordance with local and state requirements.
4. Entry into chambers may require confined space training based on state and local
regulations.
5. No fertilizer shall be used in the Biofiltration Chamber.
6. Irrigation should be provided as recommended by manufacturer and/or landscape
architect. Amount of irrigation required is dependent on plant species. Some plants
may require irrigation.
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Maintenance Procedure Illustration
Screening Device
The screening device is located directly
under the manhole or grate over the
Pre-Treatment Chamber. It’s mounted
directly underneath for easy access
and cleaning. Device can be cleaned by
hand or with a vacuum truck.
Separation Chamber
The separation chamber is located
directly beneath the screening device.
It can be quickly cleaned using a
vacuum truck or by hand. A pressure
washer is useful to assist in the
cleaning process.
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Cartridge Filters
The cartridge filters are located in the
Pre-Treatment chamber connected to
the wall adjacent to the biofiltration
chamber. The cartridges have
removable tops to access the
individual media filters. Once the
cartridge is open media can be
easily removed and replaced by hand
or a vacuum truck.
Drain Down Filter
The drain down filter is located in the
Discharge Chamber. The drain filter
unlocks from the wall mount and hinges
up. Remove filter block and replace with
new block.
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Trim Vegetation
Vegetation should be maintained in the
same manner as surrounding vegetation
and trimmed as needed. No fertilizer shall
be used on the plants. Irrigation
per the recommendation of the
manufacturer and or landscape
architect. Different types of vegetation
requires different amounts of
irrigation.
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Inspection Form
Modular Wetland System, Inc.
P. 760.433-7640
F. 760-433-3176
E. Info@modularwetlands.com
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For Office Use Only
(city) (Zip Code)(Reviewed By)
Owner / Management Company
(Date)
Contact Phone ( )_
Inspector Name Date / / Time AM / PM
Weather Condition Additional Notes
Yes
Depth:
Yes No
Modular Wetland System Type (Curb, Grate or UG Vault):Size (22', 14' or etc.):
Other Inspection Items:
Storm Event in Last 72-hours? No Yes Type of Inspection Routine Follow Up Complaint Storm
Office personnel to complete section to
the left.
2972 San Luis Rey Road, Oceanside, CA 92058 P (760) 433-7640 F (760) 433-3176
Inspection Report
Modular Wetlands System
Is the filter insert (if applicable) at capacity and/or is there an accumulation of debris/trash on the shelf system?
Does the cartridge filter media need replacement in pre-treatment chamber and/or discharge chamber?
Any signs of improper functioning in the discharge chamber? Note issues in comments section.
Chamber:
Is the inlet/outlet pipe or drain down pipe damaged or otherwise not functioning properly?
Structural Integrity:
Working Condition:
Is there evidence of illicit discharge or excessive oil, grease, or other automobile fluids entering and clogging the
unit?
Is there standing water in inappropriate areas after a dry period?
Damage to pre-treatment access cover (manhole cover/grate) or cannot be opened using normal lifting
pressure?
Damage to discharge chamber access cover (manhole cover/grate) or cannot be opened using normal lifting
pressure?
Does the MWS unit show signs of structural deterioration (cracks in the wall, damage to frame)?
Project Name
Project Address
Inspection Checklist
CommentsNo
Does the depth of sediment/trash/debris suggest a blockage of the inflow pipe, bypass or cartridge filter? If yes,
specify which one in the comments section. Note depth of accumulation in in pre-treatment chamber.
Is there a septic or foul odor coming from inside the system?
Is there an accumulation of sediment/trash/debris in the wetland media (if applicable)?
Is it evident that the plants are alive and healthy (if applicable)? Please note Plant Information below.
Sediment / Silt / Clay
Trash / Bags / Bottles
Green Waste / Leaves / Foliage
Waste:Plant Information
No Cleaning Needed
Recommended Maintenance
Additional Notes:
Damage to Plants
Plant Replacement
Plant Trimming
Schedule Maintenance as Planned
Needs Immediate Maintenance
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Maintenance Report
Modular Wetland System, Inc.
P. 760.433-7640
F. 760-433-3176
E. Info@modularwetlands.com
274
For Office Use Only
(city) (Zip Code)(Reviewed By)
Owner / Management Company
(Date)
Contact Phone ( )_
Inspector Name Date / / Time AM / PM
Weather Condition Additional Notes
Site
Map #
Comments:
2972 San Luis Rey Road, Oceanside, CA 92058 P. 760.433.7640 F. 760.433.3176
Inlet and Outlet
Pipe Condition
Drain Down Pipe
Condition
Discharge Chamber
Condition
Drain Down Media
Condition
Plant Condition
Media Filter
Condition
Long:
MWS
Sedimentation
Basin
Total Debris
Accumulation
Condition of Media
25/50/75/100
(will be changed
@ 75%)
Operational Per
Manufactures'
Specifications
(If not, why?)
Lat:MWS
Catch Basins
GPS Coordinates
of Insert
Manufacturer /
Description / Sizing
Trash
Accumulation
Foliage
Accumulation
Sediment
Accumulation
Type of Inspection Routine Follow Up Complaint Storm Storm Event in Last 72-hours? No Yes
Office personnel to complete section to
the left.
Project Address
Project Name
Cleaning and Maintenance Report
Modular Wetlands System
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