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ENGINEERING REPORT
Technical Information Report
Master Site Plan Review Submittal
Southport West Expansion
Renton, WA
PREPARED BY:
COUGHLIN PORTER LUNDEEN
801 Second Avenue, Suite 900
Seattle, WA 98104
P 206.343.0460
CONTACT / Bart Balko, PE
Renton, WA
June 24, 2022
06/24/22EXHIBIT 8
RECEIVED
Clark Close 07/15/2022
PLANNING DIVISION
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TABLE OF CONTENTS
I. PROJECT OVERVIEW .................................................................................................................................... 1
General Description .......................................................................................................................................... 1
Existing Conditions ........................................................................................................................................... 1
Proposed Drainage System .............................................................................................................................. 1
II. CONDITIONS AND REQUIREMENTS ............................................................................................................ 3
Special Requirements:...................................................................................................................................... 3
Project Specific Requirements:......................................................................................................................... 4
III. OFF-SITE ANALYSIS ..................................................................................................................................... 5
Task 1 – Study Area Definition and Maps ........................................................................................................ 5
Task 2 - Resource Review ................................................................................................................................ 5
Task 3 - Field Inspection ................................................................................................................................... 5
Task 4 - Drainage System Description and Problem Descriptions ................................................................... 5
Upstream Analysis ........................................................................................................................................ 5
Downstream Analysis .................................................................................................................................... 6
Task 5 – Mitigation of Existing or Potential Problems....................................................................................... 6
IV. FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN ....................................... 7
Existing Site Hydrology (Part A) ....................................................................................................................... 7
Developed Site Hydrology (Part B) ................................................................................................................... 7
Performance Standards and Onsite BMP’s (Parts C and D) ............................................................................ 8
Water Quality System (Part E) ........................................................................................................................ 10
V. CONVEYANCE SYSTEM ANALYSIS AND DESIGN .................................................................................. 11
Standard Requirements (based on KCSWDM and SAO): .............................................................................. 11
On-site Conveyance ....................................................................................................................................... 11
Existing Conditions: ..................................................................................................................................... 11
Developed Storm System Description: ....................................................................................................... 11
VI. SPECIAL REPORTS AND STUDIES ........................................................................................................... 13
VII. OTHER PERMITS ....................................................................................................................................... 14
VIII. CSWPPP ANALYSIS AND DESIGN .......................................................................................................... 15
Standard Requirements .................................................................................................................................. 15
ESC Analysis and Design (part A) .................................................................................................................. 16
SWPPP Plan Design (Part B) ......................................................................................................................... 16
IX. BOND QUANTITY, FACILITY SUMMARIES, AND DECLARATION OF COVENANT ............................... 18
X. OPERATION AND MAINTENANCE MANUAL ............................................................................................ 19
Standard Maintenance........................................................................................................................................
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Appendix A – Figures ..........................................................................................................................................
Figure 1 TIR Worksheet ..................................................................................................................................
Figure 2 Site Lcoation Map .............................................................................................................................
Figure 3 USDA Soil Survey Map .....................................................................................................................
Figure 4 Sensitive Areas Map .........................................................................................................................
Figure 5 Existing Southport Conditions ...........................................................................................................
Figure 6A Proposed Catchment Areas ...........................................................................................................
Figure 6B Proposed Subbasin Areas ..............................................................................................................
Figure 6C drainage Basin Map .......................................................................................................................
Figure 7 Proposed Southport Conditions ......................................................................................................
`
Figure 8 Water Treatment Sizing (Provided at a later date) ............................................................................
Figure 9 Flow Control Application Map ...........................................................................................................
Figure 10 FEMA Firm Map ..............................................................................................................................
Figure 11 Aquifer Protection Map ...................................................................................................................
Figure 12 Offsite Analysis ...............................................................................................................................
Appendix B– Engineering Calculations .............................................................................................................
Southport Park Avenue Conveyance Analysis ................................................................................................
Backwater Analysis .........................................................................................................................................
Water Treatment Sizing (Provided at a later date) ..........................................................................................
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I. PROJECT OVERVIEW
GENERAL DESCRIPTION
The following Technical Information Report (TIR) provides the technical information and design analysis
required for developing the Drainage and Temporary Erosion and Sedimentation Control Plan (TESC) for the
Southport West Expansion Project Master Site Plan Review (MSPR) Permit. The stormwater design for the
project was based on the requirements set forth in the 2017 Renton Surface Water Design Manual (RSWDM)
(See Figure 1 – Technical Information Report Worksheet).
The Southport West Expansion Project is located within the City of Renton, situated north of the existing
intersection of Park Avenue and 757th Avenue. The proposed project will consist of a phased corporate office
complex, separated into four phases (See Figure 2 – Site Location Map). The site is in the NW ¼ of the NW
¼ of Section 8, Township 23 North, Range 5 East, Willamette Meridian.
The propose phased project is for the development of up to 1,250,000 square feet of office space within five
towers on a previous Puget Sound Energy (PSE) site. Phase 1 consists of the two western most office
buildings (Towers 1 and 2), and the associated western portion of the garage podium. Phase 2 will consist of
two additional office buildings (Towers 3 and 4), to be constructed adjacent to Phase 1 to the east. Phase 3
will consist of Tower 5 to the east of Phase 1 and Phase 2, and phase 4 includes Tower 6 at the southwest
corner of the site.
The existing site consists of two parcels of mostly of gravel and asphalt with total area of 10.09 acres. The
proposed conditions will include 5.77 acres of building coverage, and the remainder being road, sidewalks and
pathways, with landscape and amenity areas. The existing site discharges stormwater runoff primarily to the
existing Southport property to the north, into a storm conveyance system known as the “PSE Bypass” storm
system. The existing PSE Bypass drainage system already accounts for portions of the Southport Hotel,
portions of the existing Office lot, portions of the Southport West property, and the Park Avenue Extension.
This PSE Bypass storm system has limited capacity for additional runoff volumes, with visual flooding
occurring during winter rainy months. The remainder of the existing PSE properties convey runoff to John’s
Creek to the east. Additionally, there is a third storm drainage system that conveys runoff between the
Southport properties, and the Bristol Developments (See Figure 5 – Existing Southport Conditions). The
proposed pollution generating surfaces will be captured by catch basins and treated in cartridge filter facilities
prior to connection into the three existing drainage systems. Soils for the area were mapped using the King
County Soil Survey maps (See Figure 3 – USDA Soil Survey Map), and results from the Geotechnical
exploration will be provided as part of future permit submittals.
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EXISTING CONDITIONS
The western parcel has a total area of 7.74 acres, and the eastern parcel has a total area of 2.35 acres, with a
combined area of 10.09 acres. Together the existing parcels have a total impervious area of 9.66 acres, and a
pervious area of 0.43 acres. The existing impervious surfaces include buildings, roadways, gravel surface
area, sidewalks and concrete platforms for PSE electrical equipment. The site is currently an active PSE
electrical facility, which will be relocated to a new area to the east during Phase 1 or prior to Phase 2. See
Figure 7 for proposed PSE relocation vicinity. The existing drainage patterns are divided into north and south
halves, with the northern areas draining to the existing PSE Bypass system and the southern areas flowing to
John’s Creek.
The current site is relatively flat with most of the existing area ranging from 22 feet to 25 feet. There is a
gradual decline of 3 feet from the southeastern point to the northwestern region. See Table 1 for site surface
cover information. The BNSF rail at the south end of the site sits at an elevation of approximately31 feet.
PROPOSED DRAINAGE SYSTEM
The proposed pollution generating surfaces include asphalt roadway paving, and concrete sidewalk
placement. Site parking will be within underground parking garages with some parallel on-street parking stalls.
The remaining site consists of building roof tops, and landscaped areas. See Table 2 for site surface cover
information. According to Table 1.1.2.A of the 2017 Renton Surface Water Design Manual (RSWDM), this
project meets the criteria for a Full Drainage Review, including water quality requirements. Per the 2017
RSWDM, since 100% of the runoff will directly discharge to major receiving water body (Lake Washington)
Basic Water Quality measures apply. We anticipate the Full Drainage Review will take place during the
construction permit process, while the intent of this report is to provide high level master plan drainage system
intent for project planning.
The proposed site will be distributed into three conveyance systems that each discharge directly to Lake
Washington. For the purposes of this report, the three connections are referred to as the PSE Bypass, Bristol
Connection, and John’s Creek. See Figure 7 for the location of these connections. The proposed drainage
improvements will include the on-site and off-site conveyance improvements to the PSE Bypass system,
connections to the Bristol conveyance system, as well as John’s Creek. The outfall to John’s Creek will be
replaced to meet current City requirements, and to meet the site’s conveyance needs. Additionally, the project
site lies within the City’s Existing Peak Flow Control basin. This project is therefore not required to provide flow
control for the replaced impervious area, provided the existing downstream system has sufficient capacity to
safely convey the proposed flows. The included conveyance analysis demonstrates that the Bristol and John’s
Creek connections have capacity for the additional flows, and with the proposed improvements, the PSE
Bypass drainage system will also have the needed capacity.
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PSE BYPASS DRAINAGE SYSTEM
The proposed improvements to the PSE Bypass drainage system include upsizing the 18” line that connects
the existing drainage tunnel south to Center Road. Additionally, an overflow conveyance line is being installed
as part of a separate project that will resolve current capacity issues that have been reported on the current
Southport Office and Hotel lots, and the current PSE site. PSE Bypass drainage system currently collects
runoff generated on portions of the Southport Office Buildings, the Center Road, the Park Avenue Extension,
and most of the existing PSE site, totaling 7.81 acres. The Southport West project will reduce the tributary
area to the PSE Bypass line to a total of 4.73 acres to help mitigate the existing flooding issues.
During Phase 1 of the Southport West project, and after the relocation of the PSE site, a temporary sediment
and detention pond may be installed to help mitigate flooding issues in the interim period before the remaining
phases are developed. Additionally, the existing site includes an approximate 0.50 acres which sheet flows to
the adjacent Boeing property. It is likely that Phase 4 would mitigate this with the proposed Phase 4 facilities
discharging into the PSE Bypass system. This is accounted for in the master plan Conveyance Analysis
included in this report.
BRISTOL DRAINAGE SYSTEM
Portions of the proposed Towers 3 and 4 will discharge roof runoff to the Bristol Drainage System. In order to
determine the available capacity of this system, the included master plan conveyance analysis evaluated the
entire Bristol tributary basin. This includes portions of the Southport Hotel, Southport Office complex, the
Bristol 1 and 2 developments, and portions of Southport Lane. Runoff volumes from the water quality storm
event of the tributary area is conveyed to a water quality vault prior to discharging to Lake Washington. An
overflow line is also available to convey excess water above the water quality storm volumes during large
storm events. In order to determine the capacity of this system, it is assumed that the water quality vault is at
full capacity and the overflow conveyance line is utilized. The Southport West Phase 2 will introduce 1.41
acres of roof area to this line, as well as 0.09 acres of the project frontage to Southport Lane. The conveyance
analysis demonstrates that the additional tributary area introduced during Phase 2 of this project does not
overload the Bristol drainage system, and the COR requirements during the 25- and 100-year storms are met.
JOHN’S CREEK DRAINAGE SYSTEM
The existing 12” outfall to John’s creek will be replaced with an 18” outfall. The existing connections to this
outfall include a 15” line, and 12” lines. The upsizing of the outfall will help with discharging the existing
tributary areas as well as the new tributary areas introduced as part of the Southport West project. The
existing tributary area to this outfall at John’s Creek includes a portion of the existing PSE site, the Bristol 2
frontage, as well as a drainage swale located east of the Bristol 2 development. After the Southport West
development is complete, the tributary area to this outfall will be 4.22 acres in the final condition. The
conveyance analysis evaluated the entire tributary basin, which determined that the existing 12” outfall must
be upsized to 18” to meet current COR conveyance requirements.
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All conveyance on site will be designed according to Chapter 4 of the 2017 Renton Surface Water Design
Manual (RSWDM). The master plan calculations and system modifications demonstrate how that can be
achieved.
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II. CONDITIONS AND REQUIREMENTS
This section will address the requirements set forth by the Core and Special Requirements listed in Chapter 1
of the City of Renton Surface Water Design Manual.
City of Renton Surface Water Design Manual Core Requirements:
1. Discharge at the Natural Location (1.2.1): This master plan project proposes to direct approximately
4.055 acres of runoff to the existing PSE Bypass drainage system, following the existing conveyance
pattern. Approximately 1.496 acres are directed to the Bristol drainage system, and the remaining
(approximate) 4.540 acres are directed to John’s Creek. All three conveyance methods tie into Lake
Washington within a quarter mile of the site.
2. Off-site Analysis (1.2.2): Refer to Sections III and IV. A Level 1 downstream analysis has been
performed, as this project will discharge to Lake Washington.
3. Flow Control (1.2.3.1): Refer to Section IV. The project is in a Peak Flow Control Area. Flow control
has not been provided for the proposed improvements, due to no increase in flow during the 100-year
event. The pre-development condition (total site) 100-year peak flow is 4.28 cfs, and the mitigated
100-year peak flow rate is 3.92 cfs.
4. Conveyance System (1.2.4): Refer to Section V. Closed pipe systems, treatment catch basin and
extension connections have been provided for stormwater conveyance.
5. Erosion and Sedimentation Control (1.2.5): Refer to Section VIII and the demolition/TESC provided
as part of this submittal. The project will construct a series of sediment controls to address the
specific conditions at the site. Specific Erosion and Sedimentation Control measures will be designed
as part of future permits.
6. Maintenance and Operations (1.2.6): Refer to Section X. The proposed storm drainage system will
be privately owned, operated, and maintained.
7. Financial Guarantees and Liability (1.2.7): The owner and contractor will obtain all necessary
permits and bonds prior to the beginning of each phase of construction.
8. Water Quality (1.2.8): Refer to Section IV. Water quality treatment for runoff from target pollution
generating surfaces will be provided by cartridge filter systems. See Section IV for more information.
9. Onsite BMP (1.2.9): Refer to Section IV. Onsite BMP’s have been assessed to the maximum extent
possible. Further review will be provided with each phase as part of future permits. See Section IV for
more information.
SPECIAL REQUIREMENTS:
Special Requirement #1. Other Adopted Area-Specific Requirements Section 1.3.1
• Critical Drainage Areas (CDAs): Not Applicable
• Master Drainage Plans (MDPs): There are no known master drainage plans covering this project site.
• Basin Plans (BPs): The project is located within the South Lake Washington – Renton drainage basin.
• Lake Management Plans (LMPs): Not Applicable
• Shared Facility Drainage Plans (SFDPs): Not Applicable
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Special Requirement #2. Flood Hazard Area Delineation, Section 1.3.2: See Figure 10 for 100-yr flood
zone. The site is within Zone X therefore no 100-yr flood plains have been delineated on the plans.
Special Requirement #3. Flood Protection Facilities, Section 1.3.3: Not Applicable
Special Requirement #4. Source Controls, Section 1.3.4: See attached Activity Worksheet and Required
BMP’s.
Special Requirement #5. Oil Control, Section 6.1.5. This office development site will not trigger this
requirement. No oil control is required.
Special Requirement #6. Aquifer Protection Area. Section 1.3.6: See attached Aquifer Protection Map under
Appendix A. The site is not located in an Aquifer Protection Zone. Not applicable.
PROJECT SPECIFIC REQUIREMENTS:
There are no applicable project specific instructions.
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III. OFF-SITE ANALYSIS
TASK 1 – STUDY AREA DEFINITION AND MAPS
The Renton drainage basin map was used to verify that the site was fully in the Lake Washington South
drainage basin (See Figure 6C – Drainage Basin Map).
TASK 2 - RESOURCE REVIEW
a) Adopted Basin Plans Lake Washington South drainage basin
b) Floodplain/floodway (FEMA) Maps Site is not in the floodplain (See Figure 10)
c) Off-site Analysis Reports None
d) Sensitive Areas Folio No Sensitive Areas. See Figure 4 and Figure 11
e) Drainage Complaints and Studies No Drainage Complaints. See Figure 4.
f) Road Drainage Problems No Current Road Drainage Problems.
g) King County Soils Survey: See Figure 3 – USDA Soil Map
h) Wetland Inventory Maps: No Wetlands. See Figure 4
i) Migrating Rivers Study Not Applicable.
j) DOE’s Section 303d List of Polluted Waters See Section VIII, Part B of this report for Category
5 listings.
k) KC Designated Water Quality Problems Not Applicable.
l) City of Renton Critical Maps: See Figure 4 and Figure 11. Project is in a
seismic area.
TASK 3 - FIELD INSPECTION
Coughlin Porter Lundeen conducted site visits in preparing the project plans. Please refer to Task 4,
Downstream Analysis below for more information.
TASK 4 - DRAINAGE SYSTEM DESCRIPTION AND PROBLEM
DESCRIPTIONS
Runoff from the site will be conveyed through new and existing storm elements that discharge to Lake
Washington. The proposed site will distribute treated runoff into either the existing PSE Bypass system, the
Bristol conveyance system and John’s Creek. See Appendix A, Figure 12 – Offsite Analysis Map.
Upstream Analysis
The site is the upstream most area for both the PSE Bypass and the Bristol conveyance systems. The site is
also the upstream most area for the conveyance system that discharges into John’s Creek. The site is not the
upstream most area for John’s Creek itself. See Figure 6A – Proposed Catchment Area, for reference.
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Downstream Analysis
As delineated in red on Figure 12 – Offsite Analysis Map, the downstream analysis begins immediately after
the furthest downstream proposed pipe ties into the existing PSE Bypass system, Bristol conveyance system,
and John’s Creek consisting of man-made catch basins. For the PSE Bypass system, runoff generated on the
project site discharges through a system of catch basins into an underground drainage tunnel, and ultimately
into Lake Washington. The distance from the PSE catch basin this project proposes to tie into to Lake
Washington is approximately 750 feet, see Figure 12 for downstream conveyance route. The conveyance
analysis as part of this project has identified flooding issues with the existing conveyance system, as well as
noted visual minor flooding issues at the current PSE owned site, and the existing Southport Officesand Hotel.
To resolve existing flooding issues, as well as to prevent flooding issues from occurring after the proposed
development is complete, this project will upsize the connection up to the underground drainage tunnel.
Additionally, an overflow conveyance system is being installed (not part of this project) that will parallel a
portion of the underground tunnel. This was installed to resolve current flooding issues. The conveyance
analysis as part of this project has determined that the existing flooding issues will be resolved with the
proposed mitigation facilities and upsized conveyance system.
The Southport West development will remove 1.13 acres of impervious area, with the proposed planted
landscape areas. However due to existing flooding issues identified, this project proposes flood mitigation
measures to minimize overtopping of existing and proposed catch basins (See Appendix B: Conveyance
Analysis Calculations). City of Renton requires an elevation difference of 0.5 feet between the energy grade
line and the RIM elevation for the 25-year storm, as well as limited overtopping of the conveyance system
during the 100-year storm. The Conveyance Analysis calculations provided demonstrate that the proposed
mitigation measures meet these requirements.
TASK 5 – MITIGATION OF EXISTING OR POTENTIAL PROBLE MS
The existing flooding issues mentioned previously in the report are mitigated with the proposed
improvements to the downstream conveyance systems. The current flooding has been witnessed on rare
occasion at the Southport Hotel loading bay area, where the existing 18” PSE Bypass line connects to
the underground drainage tunnel. Visual inspection of the drainage tunnel by SECO has determined that
the flooding issues are likely caused by blockage within the tunnel that constricts the runoff volume,
thereby surcharging the system. An overflow 24” ductile iron pipe is currently being installed by SECO to
bypass the blockage in the tunnel. Our analysis shows that this overflow pipe, along with redistributing
the site tributary areas and increasing the size of the drainage pipes to the drainage tunnel along the
PSE Bypass line, the flooding issues that are currently seen at the Southport Office and PSE sites would
be resolved. See Conveyance Calculations, located in Appendix B: Engineering Calculations, which indicate
that the system will no longer overtop the drainage system during a 100-year storm. The pipe that will connect
to the existing PSE drainage tunnel will be upsized to 24-inch to mitigate these reported flooding issues.
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IV. FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS
AND DESIGN
EXISTING SITE HYDROLOGY (PART A)
The disturbed area of 10.09 acres consists of existing asphalt and compacted gravel beyond paved areas. The
PSE facility is mostly gravel, with concrete platforms for electrical equipment, and roofed facilities. Flooding
has been reported within the PSE site caused by downstream conveyance issues that are detailed in this
report. Due to the visual confirmation of occasional flooding, coupled with the type of existing surfaces found, it
is assumed that no infiltration occurs within the site boundaries. The site slopes generally southeast to
northwest, with the majority of the site flat. The site area conditions are illustrated in Figure 7 and summarized
in Table 1 below.
TABLE 1 - EXISTING SITE CONDITIONS AREA BREAKDOWN
DESCRIPTION AREA (SQUARE FEET) AREA (ACRES)
TOTAL PERVIOUS 18,790 0.43
TOTAL IMPERVIOUS 420,780 9.66
TOTAL DISTURBED
AREA
420,780 9.66
DEVELOPED SITE HYDROLOGY (PART B)
The existing site is almost entirely compacted gravel, paved surfaces, or building rooftop. Because of the type
of surfaces documented at the site, it is assumed that little to no existing infiltration occurs. The proposed
development consists of new office buildings, underground parking facilities, and open space pedestrian
areas. Runoff collected from the proposed rooftops does not require treatment prior to discharging to
downstream conveyance systems. Runoff from the open space pedestrian areas and proposed Frontage
Road will be collected and treated by cartridge filters prior to discharging. The proposed pipe connection to the
PSE Bypass system is entirely rooftop and will not require treatment. The proposed pipe connection to the
Bristol drainage system is also entirely rooftop and will also not require treatment. Catch basins located on-site
and along the Frontage Road will include cartridge filters that treat runoff at the basic level as described in Part
E of this report. Using the rational method described in Chapter 3 of the 2017 Renton Surface Water Design
Manual, the existing 100-year peak flow rate is 4.28 cfs. The proposed site reduces this 100-year peak flow
rate to 3.92 cfs. These flow rates are determined for the total 10.09-acre site, and do not represent the
discharge rates into the three downstream conveyance systems. See Figure 7– Proposed Conditions, for
reference.
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TABLE 2 - DEVELOPED SITE CONDITIONS AREA BREAKDOWN
DESCRIPTION AREA (SQUARE FEET) AREA (ACRES)
TOTAL PERVIOUS 67,955 1.56
NEW IMPERVIOUS (NEW PGIS)
REPLACED IMPERVIOUS (REPLACED PGIS)
EXISTING IMPERVIOUS (NPGIS TO REMAIN)
0
97,655
22,540
0
2.24
0.52
TOTAL DISTURBED AREA 398,240 9.14
PERFORMANCE STANDARDS (PARTS C)
According to Section 1.2.3.1 (See Figure 9 - Flow Control Application Map) of the 2017 Renton Surface Water
Design Manual (RSWDM), this project is located within the Peak Flow Control area. Although this project lies
within a flow control basin, the project improvements are allowed to discharge directly to Lake Washington
without detention. Given that the project development satisfies all of the Direct Discharge Exemption criteria
(discussed below), flow control will not be required.
Direct Discharge Exemption Criteria:
A) The project site discharges to Lake Washington.
B) The conveyance system between the project site and the major receiving water (Lake Washington)
will extend to the ordinary high-water mark and will be comprised of manmade conveyance elements
(pipes) and will be within a private drainage easement.
C) The conveyance system will have adequate capacity to convey the 25-year peak flow (per Core
Requirement #4, Conveyance System) for the entire contributing drainage area.
D) The conveyance system will be adequately stabilized to prevent erosion
E) The direct discharge proposal will not divert flows from or increase flows to an existing wetland or
stream sufficient to cause a significant adverse impact.
To mitigate the impacts of storm and surface water runoff generated by new impervious surface onsite BMP’s
were proposed. Per Section 1.2.9 of the 2017 Renton Surface Water Design Manual (RSWDM) for
implementation of BMPs, an evaluation of the BMPs was done. These catch basins serve impervious area
only within the proposed Southport West Development as shown per Figure 6A: Proposed Catchment Area
and Figure 6B: Proposed Subbasin Area. SECO Development will assume maintenance of the cartridge filters
and catch basins as they comply with the drainage facility financial guarantee and liability requirements.
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ON-SITE BEST MANAGEMENT PRACTICES (ON-SITE BMPS) PA RT D
Onsite BMP’s have been assessed for this project to mitigate the impacts of storm and surface water runoff
generated by new impervious surfaces, existing impervious surfaces, and replaced impervious surface
targeted for mitigation. Due to direct discharge to Lake Washington, the LID performance standard does not
need to be met and bioretention, permeable pavement, and full dispersion are not required to be considered.
However, all other BMP’s have been assessed to the maximum extent possible per section 1.2.9 of the 2017
Renton Surface Water Design Manual (RSWDM). See assessment below.
On-site BMPs Assessment
SECTION
REFERENCE
BMP DESCRIPTION ACTION
Section
C.2.2
Full Infiltration
Full Infiltration is infeasible because the
groundwater level is relatively high in this
area, estimated to be 5 feet below ground
surface per the Geotechnical Analysis.
Section
C.2.3
Limited Infiltration
Limited Infiltration is infeasible because the
groundwater level is relatively high in this
area, estimated to be 5 feet below ground
surface per the Geotechnical Analysis.
Section
C.2.4
Basic Dispersion
Basic Dispersion is infeasible because there is
not sufficient length to install a dispersion
trench, and there are no locations where a
“vegetated flowpath segment” of at least 25-
feet can be created.
Section
C.2.13
Soil Amendment
Soil Amendment is feasible and will be
proposed for the site.
Section
C.2.
Perforated Pipe
Perforated Pipe has been deemed infeasible
for the project due to the infiltration issues
described above.
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WATER QUALITY SYSTEM (PART E)
Section 1.2.8.1(A) of the 2017 Renton Surface Water Design Manual (RSWDM) outlines the specific land uses
within Basic Water Quality Treatment areas which are subject to providing Enhanced Basic Water Quality
treatment. The project discharges to Lake Washington, a Basic Treatment Receiving Water, making it subject
to Basic Water Quality treatment for all new and replaced pollution generating impervious surfaces (PGIS).
This will be provided by cartridge filtration systems that are approved from the General Use Level Designation
from the Washington Department of Ecology for basic treatment. The water quality cartridge filters will be
installed with the proposed frontage road at each proposed catch basins. Additional cartridge filters are
proposed along the frontage drainage system that discharges to the Bristol drainage system.
TABLE 3. WATER QUALITY TREATMENT AREA SUMMARY
NEW PGIS
(REQ. TREATMENT AREA)
PROPOSED TREATMENT AREA
(SEE FIG 4)
% DIFFERENCE
97,655 SF (1.56 AC) 97,655 SF (1.56 AC) 0%
The specific treatment devices will be selected to meet required treatment flows, as well as convey all flows
that will generate in a 100-year storm. Figure 8 – Water Quality Treatment Facilities will be populated in future
permit submittals.
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V. CONVEYANCE SYSTEM ANALYSIS AND DESIGN
This section discusses the criteria that will be used to analyze and design the proposed storm conveyance
system.
STANDARD REQUIREMENTS (BASED ON 2017 RSWDM AND SAO):
1. Facilities must convey the 100-year flow without overtopping the crown of the roadway,
flooding buildings, and if sheet flow occurs it must pass through a drainage easement. All
stormwater conveyance will be designed such that the 100-year flow is conveyed without overtopping
the drive aisle or flooding any nearby buildings.
2. New pipe systems and culverts must convey the 25-year flow with at least 0.5 feet of
freeboard. (1.2.4.1). The new pipe systems will be designed to convey the 25-year flow. See
Conveyance Calculations under Appendix B. These new conveyance systems will meet the
conveyance requirement per Section 1.2.4.1. of the 2017 RSWDM.
3. Bridges must convey the 100-year flow and provide a minimum of two feet, varying up to six
feet, of clearance based on 25% of the mean channel width. (1.2.4-2)(4.3.5-6). This project does
not propose a bridge.
4. Drainage ditches must convey the 25-year flow with 0.5 feet of freeboard and the 100-year flow
without overtopping. (1.2.4-2). This project does not propose open channel drainage ditches.
5. Floodplain Crossings must not increase the base flood elevation by more than 0.01 feet
[41(83.C)] and shall not reduce the flood storage volume [37(82.A)]. Piers shall not be
constructed in the FEMA floodway. [41(83.F.1)]. No work is being proposed within the base flood
elevation or within the FEMA floodway.
6. Stream Crossings shall require a bridge for class 1 streams that does not disturb or banks.
For type 2 and type 3 streams, open bottom culverts or other method may be used that will not
harm the stream or inhibit fish passage. [60(95.B)]. The project does not propose a stream
crossing.
7. Discharge at natural location is required and must produce no significant impacts to the
downstream property (1.2.1-1). The project will discharge three discharge points. The conveyance
analysis as part of this report demonstrates no adverse effects to these downstream systems.
ON-SITE CONVEYANCE
Existing Conditions:
The existing PSE site is mostly compacted gravel and is generally flat. A gradual incline in elevations is
present from the northwestern edge of the site, to the southeastern.
Developed Storm System Description:
The project will add roughly 97,655 SF of new or replaced PGIS associated with the proposed development.
These PGIS surfaces will be treated and discharged to one of three downstream conveyance systems as
described in the Downstream analysis portion of Section III. (See Figure 6A – Proposed Catchment Area and
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
Figure 6B – Proposed Subbasin Area). After being treated, all PGIS and NPGIS runoff from the capture area
and unaffected existing Park Avenue will be conveyed through one of three downstream conveyance systems
and ultimately to Lake Washington.
The conveyance and backwater calculations for each of the three discharge points are provided as part of
Appendix B: Engineering Calculations. The drainage basin that discharges to the drainage tunnel west of the
Southport Hotel and Office developments is identified as PSE BYPASS. The drainage basin tributary to the
conveyance system between the Southport Hotel and Office development and the Bristol developments is
identified as BRISTOL. The final drainage basin identified as JOHN is tributary to John’s Creek. In order to
determine the total effects of the flood mitigation proposals, as well as the proposed Southport West
development, the entire tributary basins for each of the downstream conveyance systems is incorporated into
the calculations.
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
VI. SPECIAL REPORTS AND STUDIES
The geotechnical report will be included in future permit submittals.
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
VII. OTHER PERMITS
This project will require a City of Renton Civil Construction permit, City of Renton Land Use permit, and
NPDES permit.
VIII. CSWPPP ANALYSIS AND DESIGN
This section lists the requirements that will be used when designing the TESC plan for this site. A copy of the
CSWPPP will be included prior to permit issuance for each phase.
IX. BOND QUANTITY, FACILITY SUMMARIES, AND DECLARATION
OF COVENANT
A Bond Quantity Worksheet will be included prior to permit issuance for each phase.
X. OPERATION AND MAINTENANCE MANUAL
Operation and Maintenance Manual for this project will be included prior to permit issuance for each phase.
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
Appendix A – Figures
Figures
Figure 1 Technical Information Report Worksheet
Figure 2 Site Location Map
Figure 3 USGS Soil Map
Figure 4 Sensitive Areas Map
Figure 5 Existing Southport Conditions
Figure 6A Proposed Catchment Area
Figure 6B Proposed Subbasin Area
Figure 7 Proposed Southport Conditions
Figure 8 Water Treatment Sizing (Provided at a later date)
Figure 9 Flow Control Application Map
Figure 10 FEMA Map
Figure 11 Aquifer Protection Map
Figure 12 Offsite Analysis
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
CITY OF RENTON SURFACE WATER DESIGN MANUAL
2017 City of Renton Surface Water Design Manual 12/12/2016 8-A-1
REFERENCE 8-A
TECHNICAL INFORMATION REPORT (TIR)
WORKSHEET
Part 1 PROJECT OWNER AND
PROJECT ENGINEER Part 2 PROJECT LOCATION AND
DESCRIPTION
Project Owner _____________________________
Phone ___________________________________
Address __________________________________
_________________________________________
Project Engineer ___________________________
Company _________________________________
Phone ___________________________________
Project Name __________________________
CED Permit # ________________________
Location Township ________________
Range __________________
Section _________________
Site Address __________________________
_____________________________________
Part 3 TYPE OF PERMIT APPLICATION Part 4 OTHER REVIEWS AND PERMITS
Land Use (e.g., Subdivision / Short Subd.)
Building (e.g., M/F / Commercial / SFR)
Grading
Right-of-Way Use
Other _______________________
DFW HPA
COE 404
DOE Dam Safety
FEMA Floodplain
COE Wetlands
Other ________
Shoreline
Management
Structural
Rockery/Vault/_____
ESA Section 7
Part 5 PLAN AND REPORT INFORMATION
Technical Information Report Site Improvement Plan (Engr. Plans)
Type of Drainage Review
(check one):
Date (include revision
dates):
Date of Final:
Full
Targeted
Simplified
Large Project
Directed
__________________
__________________
__________________
Plan Type (check
one):
Date (include revision
dates):
Date of Final:
Full
Modified
Simplified
__________________
__________________
__________________
Figure 1 - TIR Worksheet
SECO Development
(425) 282-5833
1083 Lake Washington Blvd, Suite 50
Renton, WA 98056
Bart Balko, P.E.
Coughlin Porter Lundeen
(206) 343-0460
Southport West Extension
23N
5E
8
Renton, WA, 98056
5/6/2022
5/6/2022
1095 Lake Washington Blvd N
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
REFERENCE 8: PLAN REVIEW FORMS AND WORKSHEET
TECHNICAL INFORMATION REPORT (TIR) WORKSHEET
12/12/2016 2017 City of Renton Surface Water Design Manual 8-A-2
Part 6 SWDM ADJUSTMENT APPROVALS
Type (circle one): Standard / Blanket
Description: (include conditions in TIR Section 2)
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
Approved Adjustment No. ______________________ Date of Approval: _______________________
Part 7 MONITORING REQUIREMENTS
Monitoring Required: Yes / No
Start Date: _______________________
Completion Date: _______________________
Describe: _________________________________
_________________________________________
_________________________________________
Re: SWDM Adjustment No. ________________
Part 8 SITE COMMUNITY AND DRAINAGE BASIN
Community Plan: ____________________________________________________________________
Special District Overlays: ______________________________________________________________
Drainage Basin: _____________________________________________________________________
Stormwater Requirements: _____________________________________________________________
Part 9 ONSITE AND ADJACENT SENSITIVE AREAS
River/Stream ________________________
Lake ______________________________
Wetlands ____________________________
Closed Depression ____________________
Floodplain ___________________________
Other _______________________________
_______________________________
Steep Slope __________________________
Erosion Hazard _______________________
Landslide Hazard ______________________
Coal Mine Hazard ______________________
Seismic Hazard _______________________
Habitat Protection ______________________
_____________________________________
Figure 1 - TIR Worksheet
Lake Washington South Drainage Basin
Flow control not required. No increase in impervious area. Basic WQ required.
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
REFERENCE 8-A: TECHNICAL INFORMATION REPORT (TIR) WORKSHEET
TECHNICAL INFORMATION REPORT (TIR) WORKSHEET
2017 City of Renton Surface Water Design Manual 12/12/2016 Ref 8-A-3
Part 10 SOILS
Soil Type
______________________
______________________
______________________
______________________
Slopes
________________________
________________________
________________________
________________________
Erosion Potential
_________________________
_________________________
_________________________
_________________________
High Groundwater Table (within 5 feet)
Other ________________________________
Sole Source Aquifer
Seeps/Springs
Additional Sheets Attached
Part 11 DRAINAGE DESIGN LIMITATIONS
REFERENCE
Core 2 – Offsite Analysis_________________
Sensitive/Critical Areas__________________
SEPA________________________________
LID Infeasibility________________________
Other________________________________
_____________________________________
LIMITATION / SITE CONSTRAINT
_______________________________________
_______________________________________
_______________________________________
_______________________________________
_______________________________________
_______________________________________
Additional Sheets Attached
Part 12 TIR SUMMARY SHEET (provide one TIR Summary Sheet
per Threshold Discharge Area)
Threshold Discharge Area:
(name or description)
Core Requirements (all 8 apply):
Discharge at Natural Location Number of Natural Discharge Locations:
Offsite Analysis Level: 1 / 2 / 3 dated:__________________
Flow Control (include facility
summary sheet)
Standard: _______________________________
or Exemption Number: ____________
On-site BMPs: _______________________________
Conveyance System Spill containment located at: _____________________________
Erosion and Sediment Control /
Construction Stormwater Pollution
Prevention
CSWPP/CESCL/ESC Site Supervisor: _____________________
Contact Phone: _________________________
After Hours Phone: _________________________
Figure 1 - TIR Worksheet
loose sandy silt
Southport Park Avenue Extension Site
3
N/A
TBD
TBD
TBD
1.2.3.1A
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
REFERENCE 8: PLAN REVIEW FORMS AND WORKSHEET
TECHNICAL INFORMATION REPORT (TIR) WORKSHEET
12/12/2016 2017 City of Renton Surface Water Design Manual 8-A-4
Part 12 TIR SUMMARY SHEET (provide one TIR Summary Sheet
per Threshold Discharge Area)
Maintenance and Operation Responsibility (circle one): Private / Public
If Private, Maintenance Log Required: Yes / No
Financial Guarantees and Liability Provided: Yes / No
Water Quality (include facility
summary sheet)
Type (circle one): Basic / Sens. Lake / Enhanced Basic / Bog
or Exemption No. _______________________
Special Requirements (as applicable):
Area Specific Drainage
Requirements
Type: SDO / MDP / BP / Shared Fac. / None
Name: ________________________
Floodplain/Floodway Delineation Type (circle one): Major / Minor / Exemption / None
100-year Base Flood Elevation (or range): _______________
Datum:
Flood Protection Facilities Describe:
Source Control
(commercial / industrial land use)
Describe land use:
Describe any structural controls:
Oil Control High-Use Site: Yes / No
Treatment BMP: _________________________________
Maintenance Agreement: Yes / No
with whom? _____________________________________
Other Drainage Structures
Describe:
Figure 1 - TIR Worksheet
N/A
Cartridge WQ catch basin utilized prior to connection to existing drainage systems.
Office Building Complex, drainage modifications
Cartridge Filtration Catch
Basins, COR catch basins
Cartridge Filteration Catch Basin designed to pass 100-yr storm peak safely
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
REFERENCE 8-A: TECHNICAL INFORMATION REPORT (TIR) WORKSHEET
TECHNICAL INFORMATION REPORT (TIR) WORKSHEET
2017 City of Renton Surface Water Design Manual 12/12/2016 Ref 8-A-5
Part 13 EROSION AND SEDIMENT CONTROL REQUIREMENTS
MINIMUM ESC REQUIREMENTS
DURING CONSTRUCTION
Clearing Limits
Cover Measures
Perimeter Protection
Traffic Area Stabilization
Sediment Retention
Surface Water Collection
Dewatering Control
Dust Control
Flow Control
Control Pollutants
Protect Existing and Proposed
BMPs/Facilities
Maintain Protective BMPs / Manage
Project
MINIMUM ESC REQUIREMENTS
AFTER CONSTRUCTION
Stabilize exposed surfaces
Remove and restore Temporary ESC Facilities
Clean and remove all silt and debris, ensure
operation of Permanent BMPs/Facilities, restore
operation of BMPs/Facilities as necessary
Flag limits of sensitive areas and open space
preservation areas
Other _______________________
Part 14 STORMWATER FACILITY DESCRIPTIONS (Note: Include Facility Summary and Sketch)
Flow Control Type/Description Water Quality Type/Description
Detention
Infiltration
Regional Facility
Shared Facility
On-site BMPs
Other
________________
________________
________________
________________
________________
________________
Vegetated Flowpath
Wetpool
Filtration
Oil Control
Spill Control
On-site BMPs
Other
________________
________________
________________
________________
________________
________________
________________
Part 15 EASEMENTS/TRACTS Part 16 STRUCTURAL ANALYSIS
Drainage Easement
Covenant
Native Growth Protection Covenant
Tract
Other ____________________________
Cast in Place Vault
Retaining Wall
Rockery > 4′ High
Structural on Steep Slope
Other _______________________________
Figure 1 - TIR Worksheet
Cartridge Filtration
Outflow to Lake
Washington
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
REFERENCE 8: PLAN REVIEW FORMS AND WORKSHEET
TECHNICAL INFORMATION REPORT (TIR) WORKSHEET
12/12/2016 2017 City of Renton Surface Water Design Manual 8-A-6
Part 17 SIGNATURE OF PROFESSIONAL ENGINEER
I, or a civil engineer under my supervision, have visited the site. Actual site conditions as observed were
incorporated into this worksheet and the attached Technical Information Report. To the best of my
knowledge the information provided here is accurate.
____________________________________________________________________________________
Signed/Date
Figure 1 - TIR Worksheet
5/6/2022
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
Southport West Expansion
C200194-16 May 2022
Figure 2 - Site Location
Project Site
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
Southport West Expansion
C200194-16 May 2022 52610005261060526112052611805261240526130052613605261420559880 559940 560000 560060 560120 560180 560240
47° 30' 12'' N
122° 12' 17'' W47° 29' 56'' N
122° 12' 0'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 10N WGS84
0 100 200 400 600
Feet
0 30 60 120 180
Meters
Map Scale: 1:2,350 if printed on A portrait (8.5" x 11") sheet.
Soil Map may not be valid at this scale.
Figure 3 -USDA Soil Survey
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
36,112
3,009
City of Renton Sensitive Areas Map
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.
5/16/2019
Legend
2,04601,023
THIS MAP IS NOT TO BE USED FOR NAVIGATION
Feet
Notes
2,046
WGS_1984_Web_Mercator_Auxiliary_Sphere
Information Technology - GIS
RentonMapSupport@Rentonwa.gov
Erosion Hazard - High
Special Flood Hazard Areas (100
year flood)
Landslide
Very High
High
Moderate
Unclassified
Wetlands
Seismic Hazard Areas
Faults
Streets
Parks
Waterbodies
Designated Neighborhoods
Map
Extent2010
Map
Project Site
Figure 4 - Sensitive Areas Map
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
Southport West Expansion
C200194-16 May 2022
LOT
A
LO
T
C
NEW LOT 1CITY OF RENTON LOT LINE ADJUSTMENT
NO. LUA 19-000137
NEW LOT 2CITY OF RENTON LOT LINE ADJUSTMENT NO.LUA 19-000137
LO
T
A
PAR
C
E
L
A
PA
R
C
E
L
A
PAR
C
E
L
B
PAR
C
E
L
D
NEW LOT A
NEW LOT A
NEW LOT B75th AVE
FF=33.50
GARAGE ENTRY
FF=32.00
FF=35.00
FF=35.00
LOADING
DOCK
FF=22.00
GARAGE
ENTRY
FF=22.00
GARAGE
ENTRY
FF=22.00
GARAGE
ENTRY
FF=22.00
FF=33.50
INSIDE BUILDINGTRANSFORMER LOCATED
Level 1 - FF 22.0
Proposed Building
Level 2 - FF 35.0
EXISTING 18"
STORMWATER LINE
EX WATER
QUALITY
VAULT
BRISTOL
STORM BASIN
PUGET SOUND ENERGY
PSE BYPASS STORM
BASIN
28
8
.
0
5
f
t
SOUTHPORT OFFICE
SOUTHPORT HOTEL
BRISTOL 2
BRISTOL 1
JOHN'S CREEK
STORM BASIN
EXISTING 8'X8'
DRAINAGE TUNNEL
LAKE WASHINGTON
BRISTOL
DISCHARGE
POINT
PSE BYPASS
DISCHARGE POINT
(Into Drainage Tunnel)
EX BRISTOL 24"
OVERFLOW PIPE
DRAINAGE TUNNEL
DISCHARGE POINT
JOHN'S CREEK
DISCHARGE
POINT
Figure 5 - Existing Southport Conditions
Project Site
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
Southport West Expansion
C200194-16 May 2022
SOUTHPORT I
PSE
LOT
A
LO
T
C
NEW LOT 1
CITY OF RENTON LOT LINE ADJUSTMENT
NO. LUA 19-000137
NEW LOT 2CITY OF RENTON LOT LINE ADJUSTMENT NO.LUA 19-000137
LO
T
A
PAR
C
E
L
A
PAR
C
E
L
A
PA
R
C
E
L
B
PAR
C
E
L
D
NEW LOT A
NEW LOT A
NEW LOT BLO
G
A
N
A
V
E
N
75th AVE
FF=33.50
GARAGE ENTRY
FF=32.00
FF=35.00
FF=35.00
LOADING
DOCK
FF=22.00
GARAGE
ENTRY
FF=22.00
GARAGE
ENTRY
FF=22.00
GARAGE
ENTRY
FF=22.00
FF=33.50
INSIDE BUILDINGTRANSFORMER LOCATED
Level 1 - FF 22.0
Proposed Building
Level 2 - FF 35.0
21
3
4
5
6
78910
11
12
13
A
B
CD
EF
G
H
I
14
A
B
C
DE
FGHI
2
34
5
67
8
910111213
EXISTING 18"
STORMWATER LINE
EX WATER
QUALITY
VAULT
PSE BYPASS STORM
BASIN
JOHN'S CREEK
STORM BASIN
EXISTING 8'X8'
DRAINAGE TUNNEL
LAKE WASHINGTON
BRISTOL
DISCHARGE
POINT
PSE BYPASS
DISCHARGE POINT
(Into Drainage Tunnel)
EX BRISTOL 24"
OVERFLOW PIPE
DRAINAGE TUNNEL
DISCHARGE POINT
JOHN'S CREEK
DISCHARGE
POINT
BRISTOL
STORM BASIN
PROPOSED PSE
RELOCATED SITE
(Drainage Pattern TBD)
PUGET SOUND ENERGY
SOUTHPORT OFFICE
SOUTHPORT HOTEL
BRISTOL 2
BRISTOL 1
Figure 6A - Proposed Catchment Area
Project Site
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
Figure 6B - Proposed Subbasin Area Map
PSE
LO
T
A
LO
T
C
NEW LOT 1
CITY OF RENTON LOT LINE ADJUSTMENT
NO. LUA 19-000137
NEW LOT 2CITY OF RENTON LOT LINE ADJUSTMENT NO.
LUA 19-000137
LO
T
A
PA
R
C
E
L
A
PA
R
C
E
L
A
PA
R
C
E
L
D
75th AVE
GARAGE
ENTRY
FF=22.00
GARAGE
ENTRY
FF=22.00 8910
11
12
13
A
B
CD
EF
G
H
I14GHI234
5
67
8
910111213
EXISTING 18" STORMWATER
LINE TO BE UPSIZED TO 24"
PSE BYPASS STORM BASIN
JOHN'S CREEK STORM BASIN
JOHN'S CREEK
DISCHARGE POINT
PROPOSED PSE RELOCATED SITE
(Drainage Pattern TBD)
BRISTOL
STORM BASIN
PHASE 2
DRAINAGE
PATTERN
TBD
PHASE 1
PHASE 4
PHASE 3
South 3
(Roof):
91,000 SF
Bristol 4 (Roof):
63,675 SF
John 4 (Roof):
56,140 SF
John 2
(Roof):
30,115 SF
John 5:
20,933 SF
John 6:
13,807 SF John 4:
20,696 SF
John 3:
8,238 SF
John 2:
16,653 SF
Bristol 4:
11,328 SF
South 17:
14,282 SF
South 14:
3,005 SF
South 13:
2,508 SF
South 12:
3,073 SF
DRAINAGE
PATTERN
TBD
South 11:
3,889 SF
South 10:
5,966 SF
South 9:
7,737 SF
South 8:
4,865 SF
South 7:
2,270 SF
South 6:
1,413 SF
South 5:
2,522 SF
South 4:
4,769 SF
Southport West Expansion
C200194-16 May 2022
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
72,224
6,019
City of Renton Drainage Basin Map
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.
5/15/2019
Legend
4,09302,046
THIS MAP IS NOT TO BE USED FOR NAVIGATION
Feet
Notes
4,093
WGS_1984_Web_Mercator_Auxiliary_Sphere
Information Technology - GIS
RentonMapSupport@Rentonwa.gov
City and County Boundary
Drainage Sub Basins
<all other values>
Black River
Boren Creek
Cabbage Creek
Cedar Grove
Cedar Main Urban
China Creek
Country Creek
Duamish
East Fork May Creek
Garrison Creek
Ginger Creek
Greenes Creek
Gypsy
Honey Creek
Jenkins Creek Main
Lake Kathleen
Lake Washington - East
Lake Washington - West
Johns Creek
Lake Washington South
Little Soos Creek
Long Marsh Creek
Lower May Creek
Project Site
Figure 6C - Drainage Basin Map
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
Southport West Expansion
C200194-16 May 2022
SOUTHPORT I
PSE
LOT
A
LO
T
C
NEW LOT 1
CITY OF RENTON LOT LINE ADJUSTMENT
NO. LUA 19-000137
NEW LOT 2CITY OF RENTON LOT LINE ADJUSTMENT NO.LUA 19-000137
LOT
A
PA
R
C
E
L
A
PAR
C
E
L
A
PAR
C
E
L
B
PAR
C
E
L
D
NEW LOT A
NEW LOT A
NEW LOT B75th AVE
FF=33.50
GARAGE ENTRY
FF=32.00
FF=35.00
FF=35.00
LOADING
DOCK
FF=22.00
GARAGE
ENTRY
FF=22.00
GARAGE
ENTRY
FF=22.00
GARAGE
ENTRY
FF=22.00
FF=33.50
INSIDE BUILDINGTRANSFORMER LOCATED
Level 1 - FF 22.0
Proposed Building
Level 2 - FF 35.0
21
3
4
5
6
78910
11
12
13
A
B
CD
EF
G
H
I
14
A
B
C
DE
FGHI2
34
5
67
8
910111213
EXISTING 18"
STORMWATER LINE
EX WATER
QUALITY
VAULT
EXISTING 8'X8'
DRAINAGE TUNNEL
LAKE WASHINGTON
BRISTOL
DISCHARGE
POINT
PSE BYPASS
DISCHARGE POINT
(Into Drainage Tunnel)
EX BRISTOL 24"
OVERFLOW PIPE
DRAINAGE TUNNEL
DISCHARGE POINT
JOHN'S CREEK
DISCHARGE
POINT
PROPOSED PSE
RELOCATED SITE
(Drainage Pattern TBD)
SOUTHPORT WESTEXPANSION
SOUTHPORT OFFICE
SOUTHPORT HOTEL
BRISTOL 2
BRISTOL 1
PSE BYPASS
DRAINAGE SYSTEM
BRISTOL DRAINAGE
SYSTEM
JOHN'S CREEK
DRAINAGE SYSTEM
Figure 7 - Proposed Southport Conditions
Project Site
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
LakeDesire
ShadyLake (MudLake)
PantherLake LakeYoungs
LakeWashington
Bl a c kRi ver
Gr eenRiv
e
r
C
edarRi verUV900
UV167
UV515
UV169
UV900
UV169
UV167BN IncBN IncBBNNIInnccSSEERReennttoonn II ssss aa qquuaahh RR dd
RReennttoonnMMaappllee VVaalllleeyyRRdd
MMaapplleeVVaalllleeyyHHwwyy
110088tthhAAvveeSSEESSWW SSuunnsseettBBllvvdd RRaaiinnii
eerrAAvveeNNNE 3rd StNE 3rd St
SW 43rd StSW 43rd St SS EE CCaarrrrRR dd
NE 4th StNE 4th St
SSEE RReennttoonn MMaappllee VVaalllleeyy RRddLLooggaannAAvveeNN
SR 515SR 515PPaarrkkAAvveeNNOOaakkeessddaalleeAAvveeSSWWSSuunnsseettBBllvvddNN EE
DDuuvvaallllAAvveeNNEEI-405 FWYI-405 FWY II--440055FFWWYYSR 167SR 167114400tthh
WWaayySS
EENNEE 2277tthh SStt
115566tthhAAvveeSSEEUUnniioonnAAvveeNNEE111166tthhAAvveeSSEESW 7th StSW 7th St
N 8th StN 8th St
PP uuggeettDDrrSSEE
RR
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nnttoonnAAvvee SS
SSWW 2277tthh SStt BBeennssoonnRRddSSWWiilllliiaammssAAvveeSSMMoonnrrooeeAAvveeNNEESE 128th StSE 128th St
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vvddNNEEddmmoonnddssAAvveeNNEEAAbbeerrddeeeennAAvveeNNEEEEMM eerrcceerrWWaayyWWeessttVVaalllleeyyHHwwyyEast Valley RdEast Valley Rd,§-405
,§-405
,§-405
µ0 1 2Miles
Flow Control Application Map
Reference 15-A
Date: 01/09/2014
Flow Control Standards
Peak Rate Flow Control Standard (Existing Site Conditions)
Flow Control Duration Standard (Existing Site Conditions)
Flow Control Duration Standard (Forested Conditions)
Flood Problem Flow
Unincorporated King County Flow Control Standards
Renton City Limits
Potential Annexation Area
Figure 9 - Flow Control Application Map
Project Site
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
Figure 10 - FEMA Flood Insurance Rate Map (FIRM)
Southport West
Expansion Site
(Approximate)
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
k
k
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k HoquiamAveNEE Valley Hwy84thAveSNEParkD r
SW 7th St
SE 128th St
SE 192nd StLind Ave SWMainAveSS 132nd St
Factory
PlN
Talbot
Rd
SN 3rd St
RainierAveS
164thAveSETukwila Pk w y SPuget Dr
NE 4th St
S 3rd St
S 1 2 9 thS t68thAveSSWSunsetBlvd
SW 16th St
116thAveSEN 4th St
I
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SW 34th StMo
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WestValleyHwySSEMay ValleyRd
SunsetBlvdNS C a r r RdHouserWayNNewcastle GolfClubRd
S 133rd St
WilliamsAveSWellsAveSEMercerWay154thPlSEDuvallAveNELoganAveSMonroeAveNESunsetBlvdNEEdmondsAveNEStevens AveNWRai
ni
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AveSTalbotRdSOakesdaleAveSWTaylorAveNW164thAveSERainierAveSWestVal
leyHwyWestValleyHwyParkAveN108thAveSE6
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Av
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SWMercerWayWMercer
W
ay Lakemont
BlvdSE132ndAve SELakeWashingtonBlvdNE140thWaySE
East Valley Rd68thAveS³City of RentonSensitive Areas
0 0.5 10.25
Miles
Information Technology - GISmapsupport@rentonwa.govPrinted on: 11/12/2014
Data Sources: City of Renton, King County
This document is a graphic representation, not guaranteedto survey accuracy, and is based on the best informationavailable as of the date shown. This map is intended forCity display purposes only.
Renton City Limits
k Education
Fire Station
K Valley Medical Center
Aquifer Protection
Zone 1
Zone 1 Modified
Zone 2
Coordinate System: NAD 1983 HARN StatePlane Washington North FIPS 4601 FeetProjection: Lambert Conformal ConicDatum: North American 1983 HARN
Figure 11 - Aquifer Protection Map
Project Site
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
9,028
752
Figure 11 - Offsite Analysis Map
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.
None
5/20/2019
Legend
5120256
THIS MAP IS NOT TO BE USED FOR NAVIGATION
Feet
Notes
512
WGS_1984_Web_Mercator_Auxiliary_Sphere
Information Technology - GIS
RentonMapSupport@Rentonwa.gov
City and County Boundary
Parcels
Water Gravity Pipes
Water Mains
Mains - Other System
Water Service Areas
Lift Stations
Pressurized Mains
Renton
Private
Gravity Mains
Renton
Private
Wastewater Service Areas
KC Pressurized Mains
KC Gravity Mains
Pump Stations
Discharge Points
Stormwater Mains
Culverts
Open Drains
Facility Outlines
Private Pump Stations
Private Discharge Points
Private Pipes
Private Culverts
EXISTING PSE
DRAINAGE
SYSTEM ROUTE
Project Site
CONNECTION TO EXISTING
PSE DRAINAGE SYSTEM
Figure 12 -Offsite Analysis Map
John's
Creek
CONNECTION TO EXISTING
BRISTOL DRAINAGE SYSTEM
CONNECTION TO EXISTING JOHN'S
CREEK DRAINAGE SYSTEM
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
Appendix B – Engineering Calculations
SOUTHPORT WEST CONVEYANCE ANALYSIS
BACKWATER ANALYSIS
WATER TREATMENT SIZING (WWHM) (To be included prior to permit issuance)
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
Southport West Expansion
C200194-16 May 2022
SOUTHPORT I
PSE
LOT
A
LO
T
C
NEW LOT 1
CITY OF RENTON LOT LINE ADJUSTMENT
NO. LUA 19-000137
NEW LOT 2CITY OF RENTON LOT LINE ADJUSTMENT NO.LUA 19-000137
LOT
A
PA
R
C
E
L
A
PAR
C
E
L
A
PAR
C
E
L
B
PAR
C
E
L
D
NEW LOT A
NEW LOT A
NEW LOT B75th AVE
FF=33.50
GARAGE ENTRY
FF=32.00
FF=35.00
FF=35.00
LOADING
DOCK
FF=22.00
GARAGE
ENTRY
FF=22.00
GARAGE
ENTRY
FF=22.00
GARAGE
ENTRY
FF=22.00
FF=33.50
INSIDE BUILDINGTRANSFORMER LOCATED
Level 1 - FF 22.0
Proposed Building
Level 2 - FF 35.0
21
3
4
5
6
78910
11
12
13
A
B
CD
EF
G
H
I
14
A
B
C
DE
FGHI2
34
5
67
8
910111213
EXISTING 18"
STORMWATER LINE
EX WATER
QUALITY
VAULT
EXISTING 8'X8'
DRAINAGE TUNNEL
LAKE WASHINGTON
BRISTOL
DISCHARGE
POINT
PSE BYPASS
DISCHARGE POINT
(Into Drainage Tunnel)
EX BRISTOL 24"
OVERFLOW PIPE
DRAINAGE TUNNEL
DISCHARGE POINT
JOHN'S CREEK
DISCHARGE
POINT
PROPOSED PSE
RELOCATED SITE
(Drainage Pattern TBD)
SOUTHPORT WESTEXPANSION
SOUTHPORT OFFICE
SOUTHPORT HOTEL
BRISTOL 2
BRISTOL 1
PSE BYPASS
DRAINAGE SYSTEM
BRISTOL DRAINAGE
SYSTEM
JOHN'S CREEK
DRAINAGE SYSTEM
Appendix B.1 -Conveyance Profile Map
PROFILE C
(John's Creek)
PROFILE B (Bristol
Drainage System)
PROFILE A (PSE Bypass
Drainage System)
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
Southport West Expansion
C200194-16 May 2022
Appendix B.2 - Conveyance Calculations
Total Roof
Pave/
Conc Pervious Tc (min)
Manning's
Coefficient
2-year,24
hr (in) S (ft/ft)
Sheet Flow
Length (ft)
All Total 865,277 560,290 271,263 33,724
South 1
South 2 45,965 45,965 9.27 0.014 0.2 0.04 250
South 3 91,000 91,000 11.86 0.014 0.2 0.04 340
South 4 4,769 4,316 453 6.30 0.014 0.2 0.04
South 5 2,522 2,522 6.30 0.014 0.2 0.04
South 6 1,413 1,413 6.30 0.014 0.2 0.04
South 7 2,270 2,040 230 6.30 0.014 0.2 0.04
South 8 4,865 4,600 265 6.30 0.014 0.2 0.04
South 9 7,737 4,173 3,564 6.30 0.014 0.2 0.04
South 10 5,966 3,699 2,267 6.30 0.014 0.2 0.04
South 11 3,889 3,731 158 6.30 0.014 0.2 0.04
South 12 15,663 12,590 2,884 189 6.30 0.014 0.2 0.04 152
South 13 2,508 2,363 145 6.30 0.014 0.2 0.04
South 14 3,005 3,005 6.30 0.014 0.2 0.04
South 15 6.30 0.014 0.2 0.04
South 16 6.30 0.014 0.2 0.04
South 17 14282 13939 343 6.30 0.014 0.2 0.04
South Total 205,854 149555 48685 7614
John 1 17086 11563 5523
John 2 46768 30115 13233 3420 7.82 0.014 0.2 0.04 202
John 3 8238 8238 6.30 0.014 0.2 0.04
John 4 76836 56140 15740 4956 9.27 0.014 0.2 0.04 250
John 5 20933 19882 1051 6.30 0.014 0.2 0.04
John 6 13807 12482 1325 6.30 0.014 0.2 0.04
John Total 183668 86255 81138 16275
Bristol 1 171,994 103,418 66,856 1,720 11.89 0.014 0.2 0.04 341
Bristol 2 72,402 63,675 3,500 5,227 12.73 0.025 0.2 0.04 208
Bristol 3 118,018 95,812 21,906 300 10.73 0.014 0.2 0.04 300
Bristol 4 113,341 61,575 49,178 2,588 8.67 0.014 0.2 0.04 230
Bristol Total 475755 324480 141440 9835
Notes:
Time of Concentration is estimated for sheet flow concentrations. Time of concentration for flow within channels, and pipes is done within SSA
Manning's Roughness Coefficient for roof areas are estiamated to be 0.014
The slope of roofs are estimated to be 2% (typical)
The 2 year, 24 hour storm rainfall depth was determined from the NOAA Atlas 2, Volume 9
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
Southport West Expansion
C200194-16 May 2022
Appendix B.3 - Profile A -25 Year, 24 Hour Storm
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
Southport West Expansion
C200194-16 May 2022
Appendix B.4 - Profile A -100 Year, 24 Hour Storm
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
Southport West Expansion
C200194-16 May 2022
Appendix B.5 - Profile B -25 Year, 24 Hour Storm
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
Southport West Expansion
C200194-16 May 2022
Appendix B.6 - Profile B -100 Year, 24 Hour Storm
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
Southport West Expansion
C200194-16 May 2022
Appendix B.7 - Profile C -25 Year, 24 Hour Storm
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
Southport West Expansion
C200194-16 May 2022
Appendix B.8 - Profile C -100 Year, 24 Hour Storm
DocuSign Envelope ID: 6EA7C613-A4CD-406B-935E-3399EFC72433
