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Technical Information Report Maple Highlands
2221005.10
Section 2
Conditions and Requirements Summary
Technical Information Report Maple Highlands 2-1
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2.0 Conditions and Requirements Summary
The proposed development requires a “Full Drainage Review” per the RSWDM. The development
must comply with all nine core requirements and six special requirements.
Core Requirements
2.1.1 CR 1 – Discharge at the Natural Location
No existing drainage systems are located onsite. The existing site consists of one threshold
discharge area with one natural discharge location along the southern property line:
• Onsite Basin: The existing site slopes generally southwest at gradual slopes; runoff sheet
flows onto the neighboring properties to the south in the existing condition. Developed
runoff will be captured by a series of catch basins in the public right-of-way and conveyed
to a combination wetpool-detention pond before discharging from the project site to the
municipal storm system at the southeast property corner; existing drainage patterns will not
change.
• Bypass Basin: The Bypass Basin includes site area along the southern property line that
will not be collected due to topography in the developed condition. In the developed
condition, runoff will sheet flow to the south, bypassing the site uncontrolled; existing
drainage patterns will not change.
The Onsite and Bypass Basins discharge to the southeast and south, respectively; these flows
combine within 0.25 mile downstream. Refer to Figure 1-2: Existing Drainage Basin and
Downstream, Figure 2-1: Predeveloped Areas, and Figure 2-2: Developed Areas for basin
boundaries.
2.1.2 CR 2 – Offsite Analysis
AHBL has independently reviewed the Maple Highlands Drainage Report prepared by KPFF,
dated October 2022, and concurs with their findings that have been included in this report. KPFF
performed a Level 1 downstream analysis on January 19, 2022, as part of compliance with Core
Requirement 2. As outlined in RSWDM Section 1.2.2.1, the Tasks 1-4 below were completed as
part of the offsite analysis.
Per City review comments dated May 6, 2022, an additional Level 2 Downstream Analysis was
completed by KPFF on May 20, 2022, to address informal drainage complaints indicating a
Type 3 – Severe Flooding Problem. Information from this in-depth analysis has been added to the
appropriate tasks below. Refer to Section 3 for the Offsite Analysis.
2.1.3 CR 3 – Flow Control Facilities
According to the Flow Control Application Map in the RSWDM (refer to Figure 4-2 of this report),
the project site is required to meet the Flow Control Duration Standard Matching Forested
Conditions. Flows from the development must match the flow duration of pre-developed rates
forested (historical, pre-developed) conditions over the range of flows extending from 50% of the
2-year up to the full 50-year flow and match peaks for the 2-year and 10-year return periods.
Per City comments dated May 6, 2022, due to informal downstream drainage complaints, the
project must additionally meet the Flood Problem Flow Control standard, matching existing site
conditions for the 100-year peak, in addition to fulfilling requirements for the flow control duration
standard.
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Flow control requirements will be met using a combination wetpool-detention pond in the
southeast corner of the site.
Figure 2-1: Predeveloped Areas
Figure 2-2: Developed Areas
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Onsite Basin
The Predeveloped Basin Map (refer to Figure 2-1 of this report) shows the basin limits evaluated
for flow control. The Onsite Basin area includes the proposed improvements within the parcel and
along the frontage. The existing site slopes generally southwest at gradual slopes; runoff sheet
flows onto the neighboring properties to the south in the existing condition. The Onsite Basin is
modeled as forest to establish the target predeveloped flow control requirements.
The Developed Basin Map (refer to Figure 2-2 of this report) shows the basin limits evaluated for
flow control. Developed runoff will be captured by a series of catch basins in the public right-of-
way and conveyed to a combination wetpool-detention pond before discharge from the project
site to the municipal storm system at the southeast property corner.
Table 2-1: Onsite Basin Disturbed Area Summary
Impervious (Ac) Pervious (Ac) Total (Ac)
Predeveloped Conditions 0.00 4.61 4.61
Developed Conditions 2.42 2.19 4.61
Bypass Basin
The Developed Basin Map (refer to Figure 2-2 of this report) shows the basin limits evaluated for
flow control. The Bypass Basin includes site area along the southern property line that will not be
collected due to topography in the developed condition. In the developed condition, runoff will
sheet flow to the south, bypassing the site uncontrolled. Flow control requirements will be met
using RSWDM Section 1.2.3.2.E Mitigation of Target Surfaces That Bypass Facility.
Table 2-2: Bypass Basin Disturbed Area Summary
Impervious (Ac) Pervious (Ac) Total (Ac)
Predeveloped Conditions 0.00 0.23 0.23
Developed Conditions 0.06 0.17 0.23
Offsite Flow-Through Basin
Upstream property is tributary to the project site and is referred to as Offsite Flow-Through Basin
(refer to Figure 2-3 of this report). The Offsite Flow-Through Basin is modeled as existing
conditions.
The performance of flow control facilities can be compromised if the contributing area, beyond
that which must be mitigated by the facility, is too large. The post-developed undetained 100-year
peak flowrate from the site is 5.01 cfs; 50% of this flow is 2.50 cfs (threshold). The existing
undetained 100-year peak flowrate from the non-target offsite upstream area is 1.17 cfs, which is
below the aforementioned threshold. Therefore, the upstream area will flow through the site per
RSWDM Section 1.2.3.2.F Bypass of Runoff from Non-Target Surfaces.
Table 2-3: Offsite Flow-Through Basin Area Summary
Impervious (Ac) Pervious (Ac) Total (Ac)
Predeveloped Conditions 0.26 1.77 2.03
Developed Conditions 0.26 1.77 2.03
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Figure 2-3: Offsite Flow-Through Basin
Table 2-4: MGSFlood Point of Compliance Flow Frequency Data
Predeveloped Peak Flows
(cfs)
Developed Peak Flows
(cfs)
2-Year Peak Flow 0.34 0.16
10-Year Peak Flow 0.71 0.28
25-Year Peak Flow 1.02 0.56
100-Year Peak Flow 1.36 1.05
Table 2-5: MGSFlood Detention Pond Information
Live Storage
Detention Volume Required (Live) 49,100 cf
Detention Volume Provided (Live) 51,200 cf
Depth (incl. 6” above riser head) 4.60 ft
Riser Height 4.10 ft
Riser Diameter 18”
Circular Orifice 1 1.95 in diameter
Vertical Rectangular Orifice 2 0.25 in Wide x 20.38 in Tall
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Proposed onsite BMPs include basic dispersion via individual on-lot gravel dispersion trenches,
reduced impervious surface credit via restricted footprints, native growth retention credit, and tree
retention credit; modeling credits are not taken for any of the proposed BMPs.
Refer to Section 4 for facility sizing.
2.1.4 CR 4 – Conveyance System
The onsite stormwater networks will be sized to convey and contain the 25-year peak flow. Also,
any overflow from the 100-year runoff event may not create or aggravate a severe flooding
problem or severe erosion problem. Improvements made to existing offsite conveyance systems
to address drainage problem-specific mitigation requirements need only change existing
conveyance capacity sufficient to prevent aggravation of the drainage problems being addressed.
Refer to Section 5 for Conveyance System Analysis and Design.
2.1.5 CR 5 – Construction Stormwater Pollution Prevention (CSWPP)
Sediment-laden runoff is prohibited from entering adjacent right-of-way and downstream
conveyance systems. Temporary Erosion and Sediment Control (TESC) best management
practices (BMPs) will be implemented during construction. Additionally, coverage under the
Washington State Department of Ecology’s Construction Stormwater General Permit will be
obtained prior to civil construction permit.
The civil engineering plan set includes an erosion control plan. In addition, a CSWPP Plan has
been prepared under separate cover; refer to Figure 8-1 for the CSWPP Plan. The plans and
narrative identify BMPs for the Contractor to follow during construction to prevent erosion and
sediment migration.
2.1.6 CR 6 – Maintenance and Operations
The owner has maintenance responsibilities for onsite facilities, and the City of Renton has
maintenance responsibilities for stormwater facilities that are located within the public right-of-way of
152nd Ave SE and 154th Ave SE. Refer to Figure 10-1 for the Operations and Maintenance Manual.
2.1.7 CR 7 – Financial Guarantees and Liability
All financial guarantee and liability requirements will be met by the owner. A construction bond
will be provided as required by the City per Renton Municipal Code (RMC) 4-6-030. A
maintenance bond shall be provided, as required by the City, for public improvements; refer to
Section 9 of this report. Liability insurance shall be provided for the duration of the project, as
outlined in the RSWDM.
2.1.8 CR 8 – Water Quality Facilities
Runoff from all pollution-generating surfaces within the development area must be treated for
water quality prior to discharge from the site. As this project does not propose a specialty land
use, per Section 6.1.1 of the RSWDM, Basic Water Quality treatment is required. This project
proposes to primarily use a combination wetpool-detention pond to meet water quality
requirements.
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Water Quality Pond
Basic water quality treatment is achieved by providing a basic wetpond volume equal to 91%
water quality treatment volume calculated using an approved hydraulic model. The water quality
pond was designed per Section 6.4.1.2 of the RSWDM.
The pond has 3H:1V side slopes and is divided into two cells separated by ecology block wall
berms. The top of the berm is set at approximately the 2-year water surface. The first cell
includes 1 foot of sediment storage and contains approximately 30% of the total water quality
volume. Due to physical site constraints a stormwater adjustment is needed to utilize internal
berms to lengthen the flow path. Refer to Section 4 for facility sizing.
Table 2-6: Water Quality Pond Information
Dead Storage
Volume Required (Dead) 18,382 cf
Volume Provided (Dead) 19,980 cf
Top WQ Elevation 378.75
Cell 1 Depth 4.25 ft
Cell 1 Bottom WQ Elevation 374.50
Cell 1 Bottom Elevation 373.50
Cell 2 Depth 3.00 ft
Cell 2 Bottom WQ Elevation 375.75
Cell 2 Bottom Elevation 375.75
2.1.9 CR 9 – Onsite BMPs
According to Section 1.2.9 of the RSWDM, Core Requirement #9 can be satisfied by:
1. Application of BMPs to the maximum extent feasible; or,
2. Using a continuous runoff model to demonstrate compliance with the Low Impact
Development (LID) Performance Standard.
This development has opted to incorporate onsite BMPs to the maximum extent feasible per the
RSWDM; refer to Section 4.1.3 of this report.
2.1.10 SR 1 – Other Adopted Area-Specific Requirements
This project is not subject to any other known area-specific requirements.
2.1.11 SR 2 – Flood Hazard Area Delineation
This project is not located in a flood hazard area.
2.1.12 SR 3 – Flood Protection Facilities
This project does not modify or use a flood protection facility.
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2.1.13 SR 4 – Source Controls
Source control requirements apply to projects proposing commercial buildings or site
development, which this project does not.
2.1.14 SR 5 – Oil Control
The project does not classify as a high use site and is thus exempt from Special Requirement #5.
2.1.15 SR 6 – Aquifer Protection Area
Under current delineations of aquifer protection areas within the city, the project site is not located
within any aquifer protection area or wellhead protection zone.
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Section 3
Offsite Analysis
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3.0 Offsite Analysis
KPFF prepared a Drainage Report for Maple Highlands, dated October 2022. See Figure 3-2 for
the KPFF Offsite Analysis.
Task 1 – Study Area Definition and Maps
The proposed project site is located at 13818 152nd Ave SE and 13929 154th Ave SE in Renton,
Washington. Both properties are currently developed with detached single-family homes,
associated driveways, and various outbuildings. The existing ground cover is mostly grass and
trees of varying age and health. The existing site topography generally ranges from 0% to 10%.
See Figure 1-1 for an aerial of existing site conditions.
The study area shall extend upstream to encompass the offsite drainage area tributary to the
proposed project site. AHBL conducted a site visit on June 14, 2023, that included visual
inspection of the upstream run-on limits expected for the site and visual inspection of the
downstream noted in the KPFF Drainage Report.
The property to the north (parcel 1463400015) of the site was determined to have several catch
basins and yard drains to collect and convey drainage to the existing conveyance system in
152nd Ave SE. Upstream runoff from approximately 2.03 acres of adjacent residential properties
to the north-northeast of the site currently sheet flows onto the site due to the slightly higher
elevations. The upstream runoff will flow-through the site per Section 2, Core Requirement #3 of
this report. No exceptions to the KPFF Drainage Report downstream analysis were noted.
Task 2 – Resource Review
King County iMap, the City of Renton Maps (COR Maps), and GIS Data were reviewed to identify
any potential sensitive areas in the proximity of the project site. See Figure 2-1 for existing
drainage basin and downstream.
Wetlands: iMap does not identify any wetlands on the project site.
Streams and 100-year Floodplain: The project site is not located in the 100-year floodplain.
Erosion Hazard Areas: COR Maps identifies no erosion hazard areas on the project site.
Seismic Hazard Areas: COR Maps identifies no seismic hazard areas on the project site.
Coal Mine Hazard Areas: COR Maps identifies no coal mine hazard areas on the project site.
Basin Condition: iMap does not indicate any basin conditions.
Downstream Drainage: King County iMap was also reviewed for downstream drainage
complaints. A total of nine possible relevant complaints were identified, all in Unincorporated King
County. Table 3-1 summarizes the available compliant information in downstream order. After
review, none appear to be active issues under review by the County.
Critical Aquifer Recharge Area: iMap identifies the project within a Category 1 and 2 critical
aquifer recharge area.
Areas Susceptible to Groundwater Contamination: iMap identifies the project as being Highly
susceptible to groundwater contamination.
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Aquifer Protection Area: COR Maps does not identify the project within the Wellhead Protection
Area Zone.
Table 3-1: Downstream Drainage Compliant Summary
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Task 3 – Field Inspection
A field inspection was completed January 19, 2022, on a cloudy day with a temperature of
approximately 50 degrees. The onsite drainage basin has slopes ranging from 0% to 10%. The
project site is comprised of a single basin with surface runoff traveling primarily as sheet flow over
pervious areas. The drainage basin is comprised mostly of grass with two single-family homes,
landscaped areas, associated driveways, and various outbuildings. Based on visual inspection
and survey contour data, the low point of the site is in the southwest corner adjacent to the
neighboring properties to the south and west. The proposed downstream system to the southeast
of the project site did not show evidence of erosion or washout.
As part of the city-requested Level 2 downstream analysis, an additional field inspection was
performed on May 20, 2022, on a cloudy day with a temperature of approximately 50 degrees. To
quantify the capacity of the downstream system, measurements were taken of the existing
downstream ditches with a hand tape and hand level. City GIS was also used to check existing
slopes.
Sections of the downstream channels were then grouped by approximate ditch dimensions. The
shallowest grade (0.5%) was determined to be the most conservative and was used throughout to
estimate the ditch capacity. The minimum ditch widths and depths found were also conservatively
used for capacity calculations. Pipes carrying ditches beneath driveways were assumed to be at
0.5%.
As the proposed development will reduce the runoff generated during the 100-year storm event
(refer to Figure 4-1 for MGSFlood Calculations); and as the existing downstream system is able
to pass the 100-year storm event from the proposed development through its smallest section;
and as no additional evidence of erosion or washout were found, no additional analysis is
proposed. See Figure 3-2 for additional downstream measurements and calculations.
Task 4 – Drainage System Description and Problem Descriptions
Existing Downstream
After leaving the project site, runoff continues to sheet flow to the south through private property
until it reaches the roadside conveyance system in SE 142nd St. From there, it is conveyed by
roadside ditch to an unnamed Cedar River tributary before discharging to Cedar River
approximately 1-mile downstream.
Proposed Downstream
The development will modify the pre-existing topography and drainage patterns to divert water
from entering the neighboring property to the southwest and instead capture and convey runoff to
the municipal system to the southeast. Onsite runoff will be captured by a series of catch basins
in the public right-of-way and conveyed to a combination wetpool-detention pond before
discharge from the project site.
The pond discharges from the project site into the existing municipal system in 154th Ave SE.
Downstream runoff will be conveyed south in 154th Ave SE via existing roadside ditches (some
ditches are upsized with this project) and existing culverts (some culverts are upsized with this
project) to the intersection of 154th Ave SE and SE 142nd St. Once runoff enters the roadside ditch
system on SE 142nd St, it rejoins the existing downstream drainage path before entering the
unnamed tributary to Cedar River. The existing and proposed downstream routes join within 1/4
mile downstream of the project site.
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Section 3.0 Figures
Figure 3-2 ......... KPFF Offsite Analysis
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Section 4
Flow Control, Low Impact Development (LID), and
Water Quality Facility Analysis and Design
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4.0 Flow Control, Low Impact Development (LID), and Water Quality Facility
Analysis and Design
Flow Control
4.1.1 Existing Site Hydrology (Part A)
The site is currently occupied by two single-family homes. The existing site slopes generally
southwest at gradual slopes and runoff sheet flows onto the neighboring properties to the south in
the existing condition. The project site and neighboring soils are mapped as Alderwood gravelly
sandy loam (AgC) according to the USDA Web Soil Survey.
The Predeveloped Basin Map (refer to Figure 2-1 of this report) shows the basin limits evaluated
for flow control. The Onsite Basin area includes the proposed improvements within the parcel and
along the frontage. The Onsite Basin is modeled as forest to establish the target predeveloped
flow control requirements.
Upstream property is tributary to the project site and is referred to as Offsite Flow-Through Basin
(refer to Figure 2-3 of this report). The Offsite Flow-Through Basin is modeled as existing
conditions.
MGSFlood was used to model the existing site and tributary basin areas; refer to Figure 4-1 of
this report.
4.1.2 Developed Site Hydrology (Part B)
The Developed Basin Map (refer to Figure 2-2 of this report) shows the basin limits evaluated for
flow control. The Onsite Basin assumes full buildout of the short plat and residences, assuming
maximum 35% of each lot is developed. Additional lot impervious assumes 480 square feet of
driveway area per lot. Lots 2, 3, and 6 through 11 provide additional impervious area for
stormwater modeling to provide a combined 4,000 square feet of minimum impervious surface
area per lot. All landscape and lawn areas will meet the Soil Amendment Criteria, as outlined in
RSWDM Appendix C, Section C.2.13.1. Runoff will be collected and conveyed to a combination
wetpool-detention pond in the southeast corner of the site. After being treated and detained, the
stormwater runoff will discharge to the public storm system in 154th Ave SE.
The Bypass Basin includes site area along the southern property line that will not be collected
due to topography in the developed condition. In the developed condition, runoff will sheet flow to
the south, bypassing the site uncontrolled. Per RSWDM Section 1.2.3.2.E, Mitigation of Target
Surfaces That Bypass Facility: Some project runoff subject to flow control may bypass required
onsite flow control facilities if all the following conditions are met:
1. The point of convergence for runoff discharged from the bypassed target surfaces and from
the project’s flow control facility must be within a quarter mile downstream of the facility’s
project site discharge point, AND
The Onsite and Bypass Basins discharge to the southeast and south, respectively; these
flows combine within 0.25 mile downstream. Refer to Figure 1-2: Existing Drainage Basin and
Downstream, Figure 2-1: Predeveloped Areas, and Figure 2-2: Developed Areas for basin
boundaries.
2. The increase in the existing site conditions 100-year peak discharge from the area of
bypassed target surfaces must not exceed 0.4 cfs, AND
Condition is met by including the Bypass Basin area within the point of compliance analysis;
refer to Figure 4-1: MGSFlood Calculations. By including the bypass within the point of
compliance, the onsite flow control facility is designed to mitigate both the Onsite and Bypass
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Basins, and release at predeveloped rates. The existing site conditions 100-year peak
discharge will not be exceeded.
3. Runoff from the bypassed target surfaces must not create a significant adverse impact to
downstream drainage systems, salmonid habitat, or properties as determined by CED, AND
Bypass Basin runoff sheet flows onto the neighboring properties to the south in both the
existing and developed conditions; runoff will not create a significant adverse impact
downstream.
4. Water quality requirements applicable to the bypassed target surfaces must be met, AND
The Bypass Basin includes 0.03 acre of pollution generating surface that will bypass the site
uncontrolled. The Bypass Basin area is included within the point of compliance analysis; refer
to Figure 4-1: MGSFlood Calculations. By including the bypass within the point of
compliance, the onsite water quality facility is designed to mitigate for both the Onsite and
Bypass Basins.
5. Compensatory mitigation by a flow control facility must be provided so that the net effect at
the point of convergence downstream is the same with or without the bypass. One or
combination of the following methods may be used to provide compensatory mitigation by a
flow control facility subject to permission/approvals from other parties as deemed necessary
by CED:
a) Design the project’s flow control facility to achieve the desired effect at the point of
convergence, OR
The Bypass Basin includes 0.03 acre of pollution generating surface that will bypass the
site uncontrolled. The Bypass Basin area is included within the point of compliance
analysis; refer to Figure 4-1: MGSFlood Calculations. By including the bypass within the
point of compliance, the onsite water quality facility is designed to mitigate for both the
Onsite and Bypass Basins.
b) Design the project’s flow control facility to mitigate an existing developed area (either
onsite or offsite) that has runoff characteristics equivalent to those of the bypassed target
surfaces but is currently not mitigated or required to be mitigated to the same flow control
performance requirement as the bypassed target surfaces.
Not applicable.
The flow control durations for the proposed site are determined using the existing and developed
surface areas shown below.
Table 4-1: Modeled Basin Hydrology
Basin (acres) Predeveloped
Onsite
Developed
Onsite
Offsite
Flow-Through Bypass
Forest 4.61 0 0 0
Pervious
(Pasture) 0 0 0 0
Pervious (Lawn) 0 2.19 1.77 0.17
Impervious 0 2.42 0.26 0.06
TOTAL 4.61 4.61 2.03 0.23
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4.1.3 Performance Standards (Part C)
Area-Specific Flow Control Facility Standard
According to Figure 4-2 Flow Control Application Map, the project site is required to meet the
Flow Control Duration Standard Matching Forested Conditions. Flows from the development must
match the flow duration of pre-developed rates forested (historical, pre-developed) conditions
over the range of flows extending from 50% of the 2-year up to the full 50-year flow and match
peaks for the 2-year and 10-year return periods. Per City comments dated May 6, 2022, due to
informal downstream drainage complaints, the project must additionally meet Flood Problem Flow
Control Standard, matching existing site conditions for the 100-year peak in addition to fulfilling
requirements for the flow control duration standard.
Flow control requirements will be met using a combination wetpool-detention pond in the
southeast corner of the site.
Onsite BMP Requirements
According to Section 1.2.9 of the RSWDM, Core Requirement #9 can be satisfied by,
1. Application of BMPs to the maximum extent feasible; or,
2. Using a continuous runoff model to demonstrate compliance with the LID Performance
Standard.
This development has opted to incorporate onsite BMPs to the maximum extent feasible per the
RSWDM.
The Maple Highlands lots are classified as Small Lots (less than 22,000 square feet) per Section
1.2.9.2 of the RSWDM. The proposed project will meet the Small Lot BMP Requirements outlined
in Section 1.2.9.2.1 of the RSWDM:
1. Full Dispersion is not feasible due to limited undisturbed native vegetation, insufficient
required vegetated flow path areas, and poor soil infiltration characteristics. Onsite
infiltration testing was performed by the Geotechnical Engineer in accordance with the
RSWDM and is discussed in the geotechnical report in Figure 6-1 of this report.
2. Full Infiltration and Full Infiltration of Roof Runoff are not feasible due to poor soil infiltration
characteristics.
3. Limited Infiltration is not feasible due to poor soil infiltration characteristics.
4. Rain Gardens per Onsite BMP standards are not feasible due to poor soil infiltration
characteristics.
5. Bioretention per Onsite BMP standards is not feasible due to poor soil infiltration
characteristics.
6. Permeable Pavement is not feasible due to poor soil infiltration characteristics.
7. BMPs must be implemented, at minimum, for an impervious area equal to at least 10% of
the lot for lot sizes up to 11,000 square feet and at least 20% of the lot for lot sizes between
11,000 and 22,000 square feet; 12,884 square feet of the site must be mitigated via BMPs.
Refer to Figure 4-3 for the Onsite BMP Credit Calculations.
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8. All target impervious surfaces not mitigated by an aforementioned BMP must be mitigated
to the maximum extent feasible using the Basic Dispersion BMP per Section C.2.4 of the
RSWDM. The project proposed to utilize basic dispersion via individual on-lot gravel filled
trenches on Lots 2, 11, and 12, mitigating 10,592 square feet of roof area. Per Table
1.2.9.A of the RSWDM Onsite BMP Sizing Credits, modeling credits cannot be used for
onsite BMPs that will be privately maintained; therefore, modeling credits are not utilized for
this BMP. Refer to Figure 4-3 for the Onsite BMP Credit Calculations.
9. Reduced Impervious Surface Credit via restricted footprints is feasible and was evaluated
for the 12 residential lots. For lots smaller than 22,000 square feet, any recorded limit on
total impervious surface less than a norm of 4,000 square feet or the maximum allowed by
the lot’s zoning, whichever is smaller, qualifies for a restricted footprint credit equal to the
difference in square footage. Lots 2, 3, 6, 7, 8, 9, 10, and 11 qualify for a restricted footprint
credit, mitigating 1,768 square feet total of roof area; Lots 1, 4, 5, and 12 do not qualify for
this credit. Per RSWDM Table 1.2.9.A, Onsite BMP Sizing Credits, modeling credits cannot
be used for onsite BMPs that will be privately maintained; therefore, modeling credits are
not used for this BMP. Refer to Figure 4-3 for the Onsite BMP Credit Calculations.
10. Native Growth Retention Credit is feasible and is implemented north of Lot 7 where existing
evergreen trees are being retained. For every 3.5 square feet of native vegetated pervious
surface area that is preserved, 1 square foot of target impervious surface area is credited
as mitigated. The native growth retention area tract is 1,576 square feet, yielding
450 square feet of mitigated target impervious surface area. Per Table 1.2.9.A of the
RSWDM Onsite BMP Sizing Credits, modeling credits cannot be used for onsite BMPs that
will be privately maintained; therefore, modeling credits are not utilized for this BMP. Refer
to Figure 4-3 for the Onsite BMP Credit Calculations.
11. Tree Retention Credit is feasible and is implemented via the proposed native growth
retention area tract along the northern extents on Lot 7. Per the Landscape Architect, the
total existing evergreen canopy coverage retained is 2,370 square feet. The sizing factor
requires the credit to be 20% of the canopy area, which equates to 474 square feet of
mitigated area. Per Table 1.2.9.A of the RSWDM Onsite BMP Sizing Credits, modeling
credits cannot be used for onsite BMPs that will be privately maintained; therefore,
modeling credits are not utilized for this BMP. Refer to Figure 4-3 for the Onsite BMP Credit
Calculations.
12. Soil amendment will be implemented to the maximum extent feasible for all landscaped
surfaces.
13. Perforated Pipe Connection is not feasible due to poor soil infiltration characteristics.
Area-Specific Water Quality Treatment Menu
Runoff from all pollution-generating surfaces within the development area must be treated for
water quality prior to discharge from the site. As this project does not propose a specialty land
use, per Section 6.1.1 of the RSWDM, Basic Water Quality treatment is required. The goal of this
treatment menu is to reduce total suspended solids (TSS) by 80%.
Water quality requirements will be met using a combination wetpool-detention pond in the
southeast corner of the site. Basic wetpool geometry will provide the following:
Two cells separated by a baffle or berm. The first cell shall contain between 25% to 35% of the
total wetpool volume and shall be at least 4.0’ deep exclusive of sediment storage. 1.0’ depth of
sediment storage shall be accommodated in the first cell. The wetpool portion of the facility shall
retain a permanent pool of water throughout the wet season.
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To achieve the length to width ratio eco. block walls are provided as internal berms. The berms
are set at the WQ water surface to ensure the water quality runoff storm does not bypass the
flowpath. Refer to the wetpool exhibit 4-6. Also refer to plans for berm locations and elevations.
Table 4-2: Water Quality Pond Information
Dead Storage
Volume Required (Dead) 18,382 cf
Volume Provided (Dead) 19,980 cf
Cell 1 Depth; Volume (% total) 4.25 ft; 5,900 CF (30%)
Cell 2 Depth; Volume (% total) 3.00 ft; 14,080 CF (70%)
Technical Information Report Maple Highlands 4-6
2221005.10
Source Controls
The 2021 King County Stormwater Pollution Prevention Manual (KCSPPM) shall be referenced
for source control measures in addition to erosion and sediment control measures during
construction. For construction source controls, see Section 8, CSWPPP Analysis and Design. For
post-construction source controls, see Section 10, Operations and Maintenance Manual.
Oil Controls
Not applicable.
4.1.4 Flow Control System (Part D)
Flow control requirements will be met using a combination wetpool-detention pond in the
southeast corner of the site.
Refer to Section 2 of this report, Core Requirement #3, Table 2-4 for MGSFlood Peak Flow Rate
with 15-Minute Time Step.
Refer to Section 2 of this report, Core Requirement #3, Table 2-5 for MGSFlood Detention Pond
Information.
Refer to Figure 4-1 for MGSFlood Calculations.
Proposed onsite BMPs include basic dispersion via individual on-lot gravel dispersion trenches;
refer to Section 4.1.3 of this report for Onsite BMP information.
Refer to Figure 4-4 for Illustrative Sketch of Flow Control and Water Quality Facility.
Refer to Figure 4-5 for Illustrative Sketch of Onsite BMPs.
4.1.5 Water Quality System (Part E)
Water quality requirements will be met using a combination wetpool-detention pond in the
southeast corner of the site.
Refer to Section 2 of this report, Core Requirement #8, Table 2-6 for Water Quality Pond
Information.
Refer to Figure 4-1 for MGSFlood Calculations.
Refer to Figure 4-4 for Illustrative Sketch of Flow Control and Water Quality Facility.
Technical Information Report Maple Highlands 4-7
2221005.10
Section 4.0 Figures
Figure 4-1 ......... MGSFlood Calculations
Figure 4-2 ......... Flow Control Application Map
Figure 4-3 ......... Onsite BMP Credit Calculations
Figure 4-4 ......... Illustrative Sketch of Flow Control and Water Quality Facility
Figure 4-5 ......... Illustrative Sketch of Onsite BMPs
Figure 4-6 ......... Wetpool Exhibit
154TH AVE SECB #9
CB #6
CB #8
CB #4
CB #5
CB #2
INLET
WITH DEBRIS BARRIER
IE: 375.75 18" (N)
CB #3, 54" TYPE 2
CONTROL STRUCTURE
375
380
385
374376
377
378
379
381
382
383
384
386
387
375380385374376377378379381382383384376
37
5
3743
7
6
377381
382
38
5
38
3
384
38
6
387
380
385
381
382
383
384
387
388
390
388
389
3861
C4.1
2
C4.1375374 376377378376
377
378
388
50'
80'6'
10'
61'
TOW: 384.60
TW: 384.60
BW: 383.13
TOW: 384.60
TW: 384.60
BW: 379.59
TOW: 384.60
TW: 384.60
BW: 378.77
TOW: 384.60
TW: 384.60
BW: 378.74
TOW: 384.60
TW: 382.50
BW: 377.25
TOW: 384.60
TW: 382.50
BW: 378.79
TOW: 384.60
TW: 382.50
BW: 378.77
TOW: 384.60
TW: 384.60
BW: 378.75
BW: 378.75
TOW: 384.60
TW: 384.59
BW: 378.75
TOW: 385.75
TW: 385.26
BW: 378.75
TOW: 387.11
TW: 386.12
BW: 378.75
TOW: 387.11
TW: 387.11
BW: 378.75
TOW: 388.25
TW: 388.25BW: 378.75
TOW: 388.25
TW: 387.88BW: 378.75
TOW: 388.25
TW: 387.50
BW: 378.75
TOW: 388.25
TW: 387.12BW: 381.13
TOW: 386.88
TW: 386.88BW: 386.39
TOW: 386.88
TW: 386.60
68+0069+0070+00PI: 70+00.00
15+00 16+00
17+00PC: 14+75.23PT: 14+96.19PI: 16+54.52TOW: 384.60
TW: 382.50
BW: 379.63
TOW: 384.60
TW: 382.50
BW: 376.63
TOW: 384.60
TW: 384.60
BW: 384.35
382
383
78'
OUTLET
WITH DEBRIS BARRIER
IE: 378.75 12" (SE)
2
C4.2
POND
GATE
POND
PERIMETER
FENCING
POND GATE
14.62%R=5
5'R=4
0'
15'
15'
CB #7
385
384
CB #1
REFER TO RETAINING WALL
PLANS UNDER SEPARATE
BUILDING PERMIT
15.00' LANDSCAPE
BUFFER
15.00' LANDSCAPE
BUFFER
15.00' LANDSCAPE
BUFFER
15.00' LANDSCAPE
BUFFER
FD IE: 378.75
1.
5
4%
TOW: 386.88
TW: 386.47
BW: 386.53
26'
22'
15'
CB #2
RIM: 382.6169+00POND
GATE
EG: 382.29
EG: 382.44EG: 382.40
EG: 382.64
EG: 382.62
CB #1
RIM: 382.40
EG: 382.91EG: 382.89
EG: 382.99
EG: 382.62
29'
26'
13'
27'
61'55'
39'
105'
65'
34'
75'
26'
80'
FLOW PATH
14'
19'
22'
39'
40'
CITY OF
RENTON
IN COMPLIANCE WITH CITY OF RENTON STANDARDS
T A C O M A
2215 North 30th Street, Suite 300 Tacoma, WA 98403253.383.2422TEL 253.383.2572FAX www.ahbl.comWEB
S E A T T L E
S P O K A N E T R I - C I T I E S
MAPLE HIGHLANDS
AHBL JOB #2221005.10
39
Know what's below.
before you dig.Call
R C23004636LUA22-000122PR22-000109R-____
N
GRAPHIC SCALE
0 20 40
1" = 20 FEET
10
POND PLAN
C4.0
C4.0
24
SE 5TH PL
COMBINED DETENTION POND AND WETPOOL
SCALE: 1" = 20'
DETENTION POND (LIVE STORAGE)
EMERGENCY OVERFLOW WATER SURFACE 383.64
100-YEAR PRIMARY OVERFLOW WATER SURFACE 383.35
POND DESIGN WATER SURFACE 382.97
BOTTOM OF LIVE STORAGE 378.75
DETENTION VOLUME REQUIRED 49,100 CF
DETENTION VOLUME PROVIDED 49,200 CF
WETPOOL (DEAD STORAGE)
WATER QUALITY WATER SURFACE 378.75
CELL#1 BOTTOM OF WQ 373.75
CELL #1 BOTTOM OF SEDIMENT STORAGE/BOTTOM OF POND 372.75
CELL #2 BOTTOM OF WQ/BOTTOM OF POND 375.75
TOP OF BERM ELEVATION (2-YR WATER SURFACE)378.75
CELL #1 VOLUME REQUIRED (30%)5,515 CF
CELL #1 VOLUME PROVIDED 5,900 CF
CELL #2 VOLUME REQUIRED (70%)12,867 CF
CELL #2 VOLUME PROVIDED 14,080 CF
(BW)
BOTTOM OF WALL
GRADE
(TW) TOP OF WALL
GRADE
WALL SPOT
ELEVATION DETAIL
NOT TO SCALE
REFER TO STRUCTURAL
PLANS FOR RETAINING
WALL/FOOTING DESIGN
DETENTION
POND
EMERGENCY
OVERFLOW
SPILLWAY
RETAINING WALL PER
STRUCTURAL PLANS
TOP OF RETAINING
WALL: 384.60
15'
2 NOT TO SCALE
EMERGENCY OVERFLOW SPILLWAY
EMERGENCY OVERFLOW
SPILLWAY AND POND
ACCESS ROAD
1 SCALE: 1" = 10'
SPILLWAY AND POND ACCESS ROAD
N
GRAPHIC SCALE
0 10 20
1" = 10 FEET
5
2
C4.0
2
C4.2
2
C4.2
2
C4.2
2
C4.4
Q:\2022\2221005\10_CIV\CAD\_Site Development\2221005-SH-POND.dwgPOND PERIMETER FENCING
POND EMERGENCY
OVERFLOW SPILLWAY
AND ACCESS ROAD
1
C4.0
EMERGENCY OVERFLOW
SPILLWAY ELEV: 383.43
EMERGENCY OVERFLOW
WS ELEV: 383.64TED-40-4278R-427824
SPILLWAY ROCK LINING
GRADATION AS FOLLOWS:
PASSING 8-INCH SQUARE SIEVE:100%
PASSING 3-INCH SQUARE SIEVE:40% - 60%
PASSING 3/4-INCH SQUARE SIEVE:0% - 10%
ROCK LINING
PER
SPILLWAY
ROCK LINING
NOTE
POND ACCESS ROAD7
C3.8
PIPE
ANCHOR
3
C4.2
POND LINER NOTES
1.AFTER EXCAVATION OF POND, INFILTRATION TEST TO BE CONDUCTED BY GEOTECHNICAL
ENGINEER. IF INFILTRATION RATES ARE LESS THAN 0.02 IN/HR, NO LINING WILL BE
REQUIRED. IF INFILTRATION RATES EXCEED 0.02 IN/HR, A LOW PERMEABILITY LINING WILL
BE REQUIRED. LOW PERMEABILITY LINING SHALL PREVENT INFILTRATION GREATER THAN
0.02 IN/HR.
2.IF SOILS INFILTRATE GREATER THAN 0.02 IN/HR, BOTH CELLS TO BE LINED WITH A LOW
PERMEABILITY COMPACTED TILL LINER OR APPROVED EQUAL.
2.1.TILL LINER THICKNESS SHALL BE 18 INCHES AFTER COMPACTION.
2.2.SOIL SHALL BE COMPACTED TO 95% MININIMUM DRY DENSITY, MODIFIED PROCTOR
METHOD (ASTM D-1557).
2.3.SOIL SHOULD BE PLACED IN 6 INCH LIFTS.
2.4.GRADATION PER TABLE.
3.LINER ALTERNATIVES INCLUDE CLAY LINERS, GEOMEMBRANE LINERS, AND CONCRETE
LINERS. LINER TO BE DESIGNED BY GEOTECHNICAL ENGINEER AND SHOULD INCLUDE
DESIGN CONSIDERATIONS FOR BUOYANCY OF LOW PERMEABILITY LINER WITH REGARDS
TO POTENTIAL HIGH GROUNDWATER.
COMPACTED TILL LINER
GRADATION
SIEVE SIZE PERCENT PASSING
6 INCH 100
4 INCH 90
#4 70-100
#200 30-100
2
C4.4
4
C4.2
ECO
BLOCK
BERM
GENERAL NOTES
1.CAD FILE IS AVAILABLE TO ASSIST
WITH HORIZONTAL SITE LAYOUT.
2.15' MINIMUM LANDSCAPE BUFFER
REQUIRED BETWEEN PROPERTY LINE
AND FACE OF POND RETAINING WALL.
(TOW) TOP OF WALL ELEVATION
REFER TO STRUCTURAL PLANS
FOR TOP OF WALL ELEVATIONS
FOOTING DRAIN NOTES
1.CONNECT POND RETAINING WALL FOOTING
DRAINS TO CB #2.
2.POND RETAINING WALL FOOTING DRAIN TO BE
SET AT A MINIMUM INVERT ELEVATION OF 378.75.
3.PROVIDE 4" PERF. PVC.
4.REFER TO STRUCTURAL PLANS FOR ADDITIONAL
INFORMATION.
FD IE: 378.75
FD IE: 382.50 @
TOP OF FOOTING
FD IE: 382.50 @
TOP OF FOOTING
FD IE: 378.75
FD IE: 378.75
FD IE: 378.75
FLOWPATH LENGTH
TO WIDTH RATIO
FLOWPATH LENGTH = 280'
FLOWPATH AVERAGE WEIGHTED WIDTH = 30'
FLOWPATH LENGTH TO WIDTH RATIO = 9:1
FLOWPATH LENGTH TO WIDTH CHECK
NOT TO SCALE
FD IE: 378.75
370
375
380
385
390
370
375
380
385
390
0+00FG 386.38FG 378.020+50FG 373.50FG 375.751+00FG 375.75FG 375.751+50FG 385.33FG 385.272+00FG 2+24.99FGPOND DESIGN WS
ELEV: 382.97
WATER QUALITY WS
ELEV: 378.75
SEDIMENT STORAGE
ELEV: 374.50
1' SEDIMENT
STORAGE
POND BOTTOM
ELEV: 375.75
100-YEAR OVERFLOW WS
ELEV: 383.35
CIP RETAINING
WALL
CIP RETAINING
WALL
154TH AVE SE
ROW
PROPERTY
LINE
POND ACCESS
ROAD
POND BOTTOM
ELEV: 373.503:13:11:1EXISTING EDGE
OF ROADWAY
6'1:1
STA: 68+56.49, 49.93' LT
IE: 378.75 12" (NW)
IE: 378.75 12" (E)
RIM: 383.35
CB #3, 54" TYPE 2
CONTROL STRUCTURE
STA: 68+43.76, 11.92' LT
IE: 378.51 12" (W)
IE: 378.51 12" (E)
IE: 378.51 4" (N)
IE: 378.51 4" (S)
RIM: 382.61
CB #2, TYPE 1L
EXISTING
EXISTING
PROPOSED (SEPARATE PERMIT)
PROPOSED
24 LF 12"
CPEP @ 0.60%
40 LF 12"
CPEP @ 0.60%
7 LF 12" CPEP
@ 0.00%
4
C4.2
EMERGENCY OVERFLOW WS
ELEV: 383.64
LIVE STORAGE
CELL #2
DEAD
STORAGE
CELL #1
DEAD
STORAGE
ECO BLOCK
TOP OF WALL
ELEV: 380.75
STA: 68+40.95, 12.05' RT
IE: 378.40 18" (N)
IE: 378.97 4" (E)
IE: 377.87 18" (S)
IE: 378.37 12" (W)
RIM: 382.40
CB #1, TYPE 1L
ECO BLOCK
TOP OF WALL
ELEV: 380.75
4.25' WQ
STORAGE
370
375
380
385
390
370
375
380
385
390
5+00FG FG 378.755+50FG 375.75FG 375.756+00FG 375.75FG 378.756+50FG 388.086+65.59FG 387.55POND BOTTOM
ELEV: 375.75
WATER QUALITY WS
ELEV: 378.75
POND DESIGN WS
ELEV: 382.97
100-YEAR
OVERFLOW WS
ELEV: 383.35
CIP RETAINING
WALL
SE 5TH PL
ROW
CIP RETAINING
WALL
PROPERTY
LINE
3:11:11:1STA: 68+56.49, 49.93' LT
IE: 378.75 12" (NW)
IE: 378.75 12" (E)
RIM: 383.35
CB #3, 54" TYPE 2
CONTROL STRUCTURE
4
C4.2
EMERGENCY OVERFLOW WS
ELEV: 383.64
LIVE STORAGE
CELL #2
DEAD STORAGE 3:1374
375
380
374
375
380
0+00FG 387.27FG 375.750+50FG 375.75FG 375.751+00FG 377.281+09.11FG 382.3621.3'
TOP OF WETPOND
DEAD STORAGE
ELEV: 378.75
2-YR WATER
SURFACE
ELEV: 380.87
TOP OF ECO. BLOCK
BERM ELEV: 380.75
BOTTOM OF ECO. BLOCK BERM
ELEV: 374.75 (1.0' MIN. BURY)
12" DEPTH COMPACTED GRAVEL
LEVELING / FOUNDATION PAD
84.0'
374
375
380
374
375
380
0+00FG 387.74FG 375.750+50FG 375.75FG 375.751+00FG 377.491+09.11FG 382.33TOP OF WETPOND
DEAD STORAGE
ELEV: 378.75
2-YR WATER
SURFACE
ELEV: 380.87
TOP OF ECO. BLOCK
BERM ELEV: 380.75
BOTTOM OF ECO. BLOCK BERM
ELEV: 374.75 (1.0' MIN. BURY)
12" DEPTH COMPACTED GRAVEL
LEVELING / FOUNDATION PAD
13.2'
16.2'
33.2'72.0'
12" DEPTH COMPACTED GRAVEL
LEVELING / FOUNDATION PAD
CITY OF
RENTON
IN COMPLIANCE WITH CITY OF RENTON STANDARDS
T A C O M A
2215 North 30th Street, Suite 300 Tacoma, WA 98403253.383.2422TEL 253.383.2572FAX www.ahbl.comWEB
S E A T T L E
S P O K A N E T R I - C I T I E S
MAPLE HIGHLANDS
AHBL JOB #2221005.10
39
Know what's below.
before you dig.Call
R C23004636LUA22-000122PR22-000109R-____
POND SECTIONS
C4.1
C4.1
25
1 SCALE: H: 1" = 20', V: 1" = 2'
POND CROSS SECTION 1 2 SCALE: H: 1" = 20', V: 1" = 2'
POND CROSS SECTION 2
Q:\2022\2221005\10_CIV\CAD\_Site Development\2221005-SH-POND.dwgTED-40-4278R-427825
3 SCALE: H: 1" = 20', V: 1" = 2'
ECOLOGY BERM 1 4 SCALE: H: 1" = 20', V: 1" = 2'
ECOLOGY BERM 2
3
C4.1 4
C4.1
29'
26'
13'
27'
61'55'
39'
105'
65'
34'
75'
26'
80'
FLOW PATH
14'
19'
22'
39'
40'
WETPOOL (DEAD STORAGE)
WATER QUALITY WATER SURFACE 378.75
CELL#1 BOTTOM OF WQ 373.75
CELL #1 BOTTOM OF SEDIMENT STORAGE/BOTTOM OF POND 372.75
CELL #2 BOTTOM OF WQ/BOTTOM OF POND 375.75
TOP OF BERM ELEVATION (2-YR WATER SURFACE)378.75
CELL #1 VOLUME REQUIRED (30%)5,515 CF
CELL #1 VOLUME PROVIDED 5,900 CF
CELL #2 VOLUME REQUIRED (70%)12,867 CF
CELL #2 VOLUME PROVIDED 14,080 CF
FLOWPATH LENGTH
TO WIDTH RATIO
FLOWPATH LENGTH = 280'
FLOWPATH AVERAGE WEIGHTED WIDTH = 30'
FLOWPATH LENGTH TO WIDTH RATIO = 9:1 TOP OF WALL ELEV: 376.75.
12' WIDE CREST SPILLWAY
Civil Engineers
Structural Engineers
Landscape Architects
Community Planners
Land Surveyors
Neighbors
MAPLE HIGHLANDS EX-1WETPOOL EXHIBIT Fig. 4-6
Technical Information Report Maple Highlands
2221005.10
Section 5
Conveyance System Analysis and Design
Technical Information Report Maple Highlands 5-1
2221005.10
5.0 Conveyance System Analysis and Design
The onsite stormwater networks have been sized to convey and contain the 25-year peak flow.
Also, any overflow from the 100-year runoff event may not create or aggravate a severe flooding
problem or severe erosion problem.
Stormwater improvements will reduce discharge from the site by providing flow control. Discharge
from the control structure is provided through a 12-inch pipe to the frontage. A backwater analysis
is provided for the new conveyance system. The StormSHED program is used to provide the
backwater analysis. Several pipes onsite are upsized to 18 inches solely to lower the hydraulic
grade line of the backwater analysis. The backwater analysis indicates stormwater should not
overtop catch basin rims in the 100-year design event.
Refer to Figure 5-1 for the Backwater Analysis.
Improvements are proposed to the existing offsite downstream conveyance system to address
the drainage problem-specific mitigation requirements in the Maple Highlands preliminary plat
condition of approval; the conveyance capacity will be sufficient to prevent aggravation of the
drainage problem being addressed. A Maple Highlands Downstream TIR has been prepared by
AHBL under separate cover; the proposed downstream conveyance system has been analyzed
and shown to have sufficient capacity to convey and contain the 100-year peak flow for the
tributary area. A separate Maple Highlands Downstream TIR submittal to King County is being
made concurrent with this report.
Technical Information Report Maple Highlands 5-2
2221005.10
Section 5.0 Figures
Figure 5-1 ......... Backwater Analysis
Technical Information Report Maple Highlands
2221005.10
Section 6
Special Reports and Studies
Technical Information Report Maple Highlands 6-1
2221005.10
6.0 Special Reports and Studies
A Geotechnical Engineering Report, dated June 14, 2021, by The Riley Group Inc., is provided as
Figure 6-1.
Technical Information Report Maple Highlands 6-2
2221005.10
Section 6.0 Figures
Figure 6-1 ......... Geotechnical Engineering Report
Corporate Office
17522 Bothell Way Northeast
Bothell, Washington 98011
Phone 425.415.0551
Corporate Office
17522 Bothell Way Northeast
Bothell, Washington 98011
Phone 425.415.0551
Technical Information Report Maple Highlands
2221005.10
Section 7
Other Permits
Technical Information Report Maple Highlands 7-1
2221005.10
7.0 Other Permits
Required permits for the project include a Preliminary and Final Short Plat application, Right-of-
Way and Site Grading Permits, and City of Renton residential building permits. Because this site
is greater than 1.0 acre, a National Pollutant Discharge Elimination System (NPDES) permit
through Department of Ecology will be required prior to start of construction.
City of Renton Civil Construction Permit for onsite and offsite roadway, grading, and utility
construction within City of Renton jurisdiction.
A King County Right-of-Way Permit required for downstream conveyance system adjustments
required by downstream analysis within King County jurisdiction.
Technical Information Report Maple Highlands
2221005.10
Section 8
CSWPPP Analysis and Design
Technical Information Report Maple Highlands 8-1
2221005.10
8.0 CSWPPP Analysis and Design
A CSWPPP is provided as Figure 8-1.
Technical Information Report Maple Highlands 8-2
2221005.10
Section 8.0 Figures
Figure 8-1 ......... CSWPPP
Technical Information Report Maple Highlands
2221005.10
Section 9
Bond Quantities, Facility Summaries, and Declaration
of Covenant
Technical Information Report Maple Highlands 9-1
2221005.10
9.0 Bond Quantities, Facility Summaries, and Declaration of Covenant
Refer to Figure 9-1 for the Bond Quantities Worksheet.
No storm drainage covenant is required with the final plat. Individual drainage covenants will be
required for the building permit application for each lot.
Refer to Figure 9-3 for the Flow Control and Water Quality Facility Summary Sheet.
Refer to Figure 9-4 for the Flow Control and Water Quality Facility Summary Site Plan.
Technical Information Report Maple Highlands 9-2
2221005.10
Section 9.0 Figures
Figure 9-1 ......... Bond Quantities Worksheet
Figure 9-2 ......... Not Used
Figure 9-3 ......... Flow Control and Water Quality Facility Summary Sheet
Figure 9-4 ......... Flow Control and Water Quality Facility Summary Site Plan
1055 South Grady Way – 6th Floor | Renton, WA 98057 (425) 430-7200••Section I: Project Information•••Section II: Bond Quantities Worksheets••Section II.a EROSION CONTROL (Stabilization/Erosion Sediment Control (ESC))•Section II.b TRANSPORTATION (Street and Site Improvements)•Section II.c DRAINAGE (Drainage and Stormwater Facilities): •Section II.d WATER - ONLY APPLICABLE IF WATER SERVICE IS PROVIDED BY CITY OF RENTON•Section II.e SANITARY SEWER - ONLY APPLICABLE IF SEWER SERVICE IS PROVIDED BY CITY OF RENTON••••••Section III. Bond Worksheet•BOND QUANTITY WORKSHEET INSTRUCTIONSThis worksheet is intended to be a "working" copy of the bond quantity worksheet, which will be used throughout all phases of the project, from initial submittal to project close-out approval. Submit this workbook, in its entirety, as follows:The following forms are to be completed by the engineer/developer/applicant as applicable to the project: The Bond Worksheet form will auto-calculate and auto-populate from the information provided in Section I and Section II.This section includes all pertinent information for the projectSection II contains a separate spreadsheet TAB for each of the following specialties: (1) electronic copy (.xlsx format) and (1) hard copy of the entire workbook for civil construction permit submittal. Hard copies are to be included as part of the Technical Information Report (TIR).(1) electronic copy (.xlsx format) and (1) hard copy of the entire workbook for final close-out submittal.This section must be completed in its entiretyInformation from this section auto-populates to all other relevant areas of the workbookThis section calculates the required Permit Bond for construction permit issuance as well as the required Maintenance Bond for project close-out submittals to release the permit bond on a project. All unit prices include labor, equipment, materials, overhead, profit, and taxes. Complete the 'Quantity' columns for each of the appropriate section(s). Include existing Right-of-Way (ROW), Future Public Improvements and Private Improvements.The 'Quantity Remaining' column is only to be used when a project is under construction. The City allows one (1) bond reduction during the life of the project with the exception of the maintenance period reduction.Excel will auto-calculate and auto-populate the relevant fields and subtotals throughout the document. Only the 'Quantity' columns should need completing.Additional items not included in the lists can be added under the "write-in" sections. Provide a complete description, cost estimate and unit of measure for each write-in item. Note: Private improvements, with the exception of stormwater facilities, are not included in the bond amount calculation, but must be entered on the form. Stormwater facilities (public and private) are required to be included in the bond amount.Page 1 of 15Ref 8-H Bond Quantity WorksheetINSTRUCTIONSVersion: 4/1/2024Printed 10/11/2024
1055 South Grady Way – 6th Floor | Renton, WA 98057 (425) 430-7200Date Prepared: Name:PE Registration No:Firm Name:Firm Address:Phone No.Email Address:Project Name: Project Owner:CED Plan # (LUA): Phone:CED Permit # (C):Address: Site Address:Street Intersection: Addt'l Project Owner:Parcel #(s): Phone:Address: Clearing and grading greater than or equal to 5,000 board feet of timber? Yes/No:NOWater Service Provided by:If Yes, Provide Forest Practice Permit #:Sewer Service Provided by: Total Estimated Construction CostsEA + B + C + D1,852,790.27$ Estimated Civil Construction Permit - Construction Costs2Stormwater (Drainage)C289,013.17$ As outlined in City Ordinance No. 4345, 50% of the plan review and inspection fees are to be paid at Permit Submittal. The balance is due at Permit Issuance. Significant changes or additional review cycles (beyond 3 cycles) during the review process may result in adjustments to the final review fees.Roadway (Erosion Control + Transportation)D1,303,272.10$ WaterAWastewater (Sanitary Sewer)B260,505.00$ AddressAbbreviated Legal Description:CEDAR RIVER FIVE ACRE TRS PP ACT 39923602 MOBILE HOME S 1/2 OF E 1/2. CEDAR RIVER FIVE ACRE TRS S 110 FT OF W 1/2 OF LOT 3 TGW N 1/2 OF LOT 4 - AKA LOT B OF KC LOT LINE ADJ NO 8908008 APPROVED NOVEMBER 30, 1989City, State, Zip13929 154th Ave. SE & 13818 152nd Ave. SE12600 SE 38th St., Ste. 250N/ASE 5th Pl & 153rd Ave. SE1-888-302-125210/11/2024Prepared by:FOR CONSTRUCTIONProject Phase 1skaul@ahbl.comScott Kaul, PE46972AHBL, Inc.2215 N. 30th St., Ste. 300, Tacoma, WA 98403253-383-2422SITE IMPROVEMENT BOND QUANTITY WORKSHEETPROJECT INFORMATIONKC WATER DISTRICT 90CITY OF RENTONPhoneEngineer Stamp Required (all cost estimates must have original wet stamp and signature)Clearing and Grading Utility ProvidersN/AProject Location and Description Project Owner InformationMaple HighlandsBellevue, WA 980061463400020 & 1463400021Dalton Smith (Agent), Conner Homes GroupPage 2 of 15Ref 8-H Bond Quantity WorksheetSECTION I PROJECT INFORMATIONVersion 4/1/2024Printed 10/11/202410/11/2024
10.3%2 All prices include labor, equipment, materials, overhead, profit, and taxes. City of Renton Sales Tax is:1 Select the current project status/phase from the following options: For Approval - Preliminary Data Enclosed, pending approval from the City; For Construction - Estimated Data Enclosed, Plans have been approved for contruction by the City; Project Closeout - Final Costs and Quantities Enclosed for Project Close-out SubmittalPage 3 of 15Ref 8-H Bond Quantity WorksheetSECTION I PROJECT INFORMATIONVersion 4/1/2024Printed 10/11/2024
CED Permit #:UnitReference #PriceUnitQuantity CostBackfill & compaction-embankmentESC-17.50$ CY Check dams, 4" minus rockESC-2SWDM 5.4.6.390.00$ Each190.00Catch Basin ProtectionESC-3145.00$ Each355,075.00Crushed surfacing 1 1/4" minusESC-4WSDOT 9-03.9(3)110.00$ CY DitchingESC-510.50$ CY Excavation-bulkESC-62.30$ CY Fence, siltESC-7SWDM 5.4.3.15.00$ LF1480.36737,401.84Fence, Temporary (NGPE)ESC-81.75$ LF500875.00Geotextile FabricESC-93.00$ SY Hay Bale Silt TrapESC-100.60$ Each HydroseedingESC-11SWDM 5.4.2.40.90$ SY20930.6076718,837.55Interceptor Swale / DikeESC-121.15$ LF868.3852998.64Jute MeshESC-13SWDM 5.4.2.24.00$ SY Level SpreaderESC-142.00$ LF Mulch, by hand, straw, 3" deepESC-15SWDM 5.4.2.12.90$ SY Mulch, by machine, straw, 2" deepESC-16SWDM 5.4.2.12.30$ SY Piping, temporary, CPP, 6"ESC-1713.75$ LF Piping, temporary, CPP, 8"ESC-1816.00$ LF Piping, temporary, CPP, 12"ESC-1920.50$ LF651,332.50Plastic covering, 6mm thick, sandbaggedESC-20SWDM 5.4.2.34.60$ SY Rip Rap, machine placed; slopesESC-21WSDOT 9-13.1(2)51.00$ CY35.70370371,820.89Rock Construction Entrance, 50'x15'x1'ESC-22SWDM 5.4.4.12,050.00$ Each12,050.00Rock Construction Entrance, 100'x15'x1'ESC-23SWDM 5.4.4.13,675.00$ Each Sediment pond riser assemblyESC-24SWDM 5.4.5.22,525.00$ Each12,525.00Sediment trap, 5' high berm ESC-25SWDM 5.4.5.122.00$ LF334.47,356.80Sed. trap, 5' high, riprapped spillway berm section ESC-26SWDM 5.4.5.180.00$ LF Seeding, by handESC-27SWDM 5.4.2.41.15$ SY Sodding, 1" deep, level groundESC-28SWDM 5.4.2.59.20$ SY Sodding, 1" deep, sloped groundESC-29SWDM 5.4.2.511.50$ SY TESC SupervisorESC-30125.00$ HR405,000.00Water truck, dust controlESC-31SWDM 5.4.7160.00$ HR406,400.00UnitReference #PriceUnitQuantity Cost EROSION/SEDIMENT SUBTOTAL:59,763.22SALES TAX @ 10.3%6,155.61EROSION/SEDIMENT TOTAL:65,918.83(A)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR EROSION & SEDIMENT CONTROLDescription No.(A)WRITE-IN-ITEMS Page 4 of 15Ref 8-H Bond Quantity WorksheetSECTION II.a EROSION_CONTROLVersion: 4/01/2024Printed 10/11/2024
CED Permit #:ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostGENERAL ITEMS Backfill & Compaction- embankmentGI-17.00$ CYBackfill & Compaction- trenchGI-210.25$ CY158.091,620.42Clear/Remove Brush, by hand (SY)GI-31.15$ SYBollards - fixedGI-4275.00$ EachBollards - removableGI-5520.00$ EachClearing/Grubbing/Tree RemovalGI-611,475.00$ Acre1.318915,134.38Excavation - bulkGI-72.30$ CY1546735,574.10Excavation - TrenchGI-85.75$ CY158.09909.02Fencing, cedar, 6' highGI-923.00$ LFFencing, chain link, 4'GI-1044.00$ LFFencing, chain link, vinyl coated, 6' highGI-1123.00$ LF438.2710,080.21Fencing, chain link, gate, vinyl coated, 20' GI-121,600.00$ Each23,200.00Fill & compact - common barrowGI-1328.75$ CY7382212,232.50Fill & compact - gravel baseGI-1431.00$ CYFill & compact - screened topsoilGI-1544.75$ CYGabion, 12" deep, stone filled mesh GI-1674.50$ SYGabion, 18" deep, stone filled mesh GI-17103.25$ SYGabion, 36" deep, stone filled meshGI-18172.00$ SYGrading, fine, by handGI-192.90$ SYGrading, fine, with graderGI-202.30$ SY1359.13,125.932101.74,833.91Monuments, 3' LongGI-211,025.00$ Each22,050.0033,075.00Sensitive Areas SignGI-228.00$ EachSodding, 1" deep, sloped groundGI-239.25$ SYSurveying, line & gradeGI-24975.00$ Day1975.001975.00Surveying, lot location/linesGI-252,050.00$ Acre12,050.00Topsoil Type A (imported)GI-2632.75$ CYTraffic control crew ( 2 flaggers )GI-27137.75$ HRTrail, 4" chipped woodGI-289.15$ SYTrail, 4" crushed cinderGI-2910.25$ SYTrail, 4" top courseGI-3013.75$ SYConduit, 2"GI-315.75$ LFWall, retaining, concreteGI-3263.00$ SF317.7720,019.51932.7358,761.99Wall, rockeryGI-3317.25$ SFSUBTOTAL THIS PAGE:8,680.3728,903.42337,033.18(B)(C)(D)(E)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR STREET AND SITE IMPROVEMENTSQuantity Remaining (Bond Reduction) (B)(C)Page 5 of 15Ref 8-H Bond Quantity WorksheetSECTION II.b TRANSPORTATIONVersion: 4/1/2024Printed 10/11/2024
CED Permit #:ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostSITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR STREET AND SITE IMPROVEMENTSQuantity Remaining (Bond Reduction) (B)(C)ROAD IMPROVEMENT/PAVEMENT/SURFACINGAC Grinding, 4' wide machine < 1000syRI-134.50$ SYAC Grinding, 4' wide machine 1000-2000syRI-218.25$ SYAC Grinding, 4' wide machine > 2000syRI-311.50$ SYAC Removal/DisposalRI-440.00$ SY540.9421,637.60311.6712,466.80Barricade, Type III ( Permanent )RI-564.25$ LF311,991.75281,799.00Guard RailRI-634.50$ LF30010,350.00Curb & Gutter, rolledRI-719.50$ LFCurb & Gutter, verticalRI-814.25$ LF594.058,465.211338.319,070.78Curb and Gutter, demolition and disposalRI-920.50$ LF24.747507.31Curb, extruded asphaltRI-106.25$ LF27168.75Curb, extruded concreteRI-118.00$ LFSawcut, asphalt, 3" depthRI-123.00$ LF1012.13,036.30Sawcut, concrete, per 1" depthRI-135.00$ LFSealant, asphaltRI-142.25$ LF1012.12,277.23Shoulder, gravel, 4" thickRI-1517.25$ SYSidewalk, 4" thickRI-1643.50$ SY280.3312,194.36681.9329,663.96Sidewalk, 4" thick, demolition and disposalRI-1737.00$ SY17.834659.86Sidewalk, 5" thickRI-1847.00$ SY85.3334,010.65284.4413,368.68Sidewalk, 5" thick, demolition and disposalRI-1946.00$ SYSign, Handicap RI-2097.00$ EachStriping, per stallRI-218.00$ EachStriping, thermoplastic, ( for crosswalk )RI-223.50$ SF2484.00Striping, 4" reflectorized lineRI-230.55$ LFAdditional 2.5" Crushed SurfacingRI-244.15$ SYHMA 1/2" Overlay 1.5" RI-2516.00$ SYHMA 1/2" Overlay 2"RI-2620.75$ SY1359.128,201.332101.743,610.28100.652,088.49HMA Road, 2", 4" rock, First 2500 SYRI-2732.25$ SYHMA Road, 2", 4" rock, Qty. over 2500SYRI-2824.00$ SYHMA Road, 4", 6" rock, First 2500 SYRI-2951.75$ SY1359.170,333.432101.7108,762.98100.655,208.64HMA Road, 4", 6" rock, Qty. over 2500 SYRI-3042.50$ SY1359.157,761.752101.789,322.25100.654,277.63HMA Road, 4", 4.5" ATBRI-3143.50$ SYGravel Road, 4" rock, First 2500 SYRI-3217.25$ SYGravel Road, 4" rock, Qty. over 2500 SYRI-3311.50$ SYThickened EdgeRI-3410.00$ LF297.122,971.20SUBTOTAL THIS PAGE:211,076.77319,171.8624,041.55(B)(C)(D)(E)Page 6 of 15Ref 8-H Bond Quantity WorksheetSECTION II.b TRANSPORTATIONVersion: 4/1/2024Printed 10/11/2024
CED Permit #:ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostSITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR STREET AND SITE IMPROVEMENTSQuantity Remaining (Bond Reduction) (B)(C)PARKING LOT SURFACINGNo.2" AC, 2" top course rock & 4" borrowPL-124.00$ SY2" AC, 1.5" top course & 2.5" base coursePL-232.00$ SY4" select borrowPL-35.75$ SY1.5" top course rock & 2.5" base coursePL-416.00$ SYSUBTOTAL PARKING LOT SURFACING:(B)(C)(D)(E)LANDSCAPING & VEGETATIONNo.Street TreesLA-1250.00$ EA5313,250.00Median LandscapingLA-2Right-of-Way LandscapingLA-30.75$ SF1574311,807.25Wetland LandscapingLA-4SUBTOTAL LANDSCAPING & VEGETATION:25,057.25(B)(C)(D)(E)TRAFFIC & LIGHTINGNo.SignsTR-1250.00$ EACH82,000.00174,250.00Street Light System ( # of Poles)TR-28,000.00$ EACH648,000.0018144,000.00Traffic SignalTR-3Traffic Signal ModificationTR-4SUBTOTAL TRAFFIC & LIGHTING:50,000.00148,250.00(B)(C)(D)(E)WRITE-IN-ITEMSNDCBUWI-15,000.00$ EACH15,000.00ROW IrrigationWI-21.00$ SF1574315,743.00SUBTOTAL WRITE-IN ITEMS:20,743.00STREET AND SITE IMPROVEMENTS SUBTOTAL:269,757.14542,125.53361,074.73SALES TAX @ 10.3%27,784.9855,838.9337,190.70STREET AND SITE IMPROVEMENTS TOTAL:297,542.12597,964.46398,265.42(B)(C)(D)(E)Page 7 of 15Ref 8-H Bond Quantity WorksheetSECTION II.b TRANSPORTATIONVersion: 4/1/2024Printed 10/11/2024
CED Permit #:ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostDRAINAGE (CPE = Corrugated Polyethylene 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/DD-130.00$ SY190.985,729.40* (CBs include frame and lid)BeehiveD-2103.00$ Each1103.00Through-curb Inlet FrameworkD-3460.00$ EachCB Type ID-41,725.00$ Each58,625.0046,900.00610,350.00CB Type ILD-52,000.00$ Each12,000.00CB Type II, 48" diameterD-63,500.00$ Each621,000.00 for additional depth over 4' D-7550.00$ FT2011,000.00CB Type II, 54" diameterD-84,075.00$ Each14,075.0014,075.00 for additional depth over 4'D-9570.00$ FT31,710.001570.00CB Type II, 60" diameterD-104,225.00$ Each for additional depth over 4'D-11690.00$ FTCB Type II, 72" diameterD-126,900.00$ Each for additional depth over 4'D-13975.00$ FTCB Type II, 96" diameterD-1416,000.00$ Each for additional depth over 4'D-151,050.00$ FTTrash Rack, 12"D-16400.00$ Each2800.00Trash Rack, 15"D-17470.00$ EachTrash Rack, 18"D-18550.00$ EachTrash Rack, 21"D-19630.00$ EachCleanout, PVC, 4"D-20170.00$ EachCleanout, PVC, 6"D-21195.00$ Each4780.00Cleanout, PVC, 8"D-22230.00$ EachCulvert, PVC, 4" D-2311.50$ LFCulvert, PVC, 6" D-2415.00$ LFCulvert, PVC, 8" D-2517.00$ LFCulvert, PVC, 12" D-2626.00$ LFCulvert, PVC, 15" D-2740.00$ LFCulvert, PVC, 18" D-2847.00$ LFCulvert, PVC, 24"D-2965.00$ LFCulvert, PVC, 30" D-3090.00$ LFCulvert, PVC, 36" D-31150.00$ LFCulvert, CMP, 8"D-3222.00$ LFCulvert, CMP, 12"D-3333.00$ LFSUBTOTAL THIS PAGE:10,625.0044,685.0022,407.40(B)(C)(D)(E)Quantity Remaining (Bond Reduction) (B)(C)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESPage 8 of 15Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEVersion: 4/1/2024Printed 10/11/2024
CED Permit #:ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostQuantity Remaining (Bond Reduction) (B)(C)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESDRAINAGE (Continued)Culvert, CMP, 15"D-3440.00$ LFCulvert, CMP, 18"D-3547.00$ LFCulvert, CMP, 24"D-3664.00$ LFCulvert, CMP, 30"D-3790.00$ LFCulvert, CMP, 36"D-38150.00$ LFCulvert, CMP, 48"D-39218.00$ LFCulvert, CMP, 60"D-40310.00$ LFCulvert, CMP, 72"D-41400.00$ LFCulvert, Concrete, 8"D-4248.00$ LFCulvert, Concrete, 12"D-4355.00$ LFCulvert, Concrete, 15"D-4489.00$ LFCulvert, Concrete, 18"D-45100.00$ LFCulvert, Concrete, 24"D-46120.00$ LFCulvert, Concrete, 30"D-47145.00$ LFCulvert, Concrete, 36"D-48175.00$ LFCulvert, Concrete, 42"D-49200.00$ LFCulvert, Concrete, 48"D-50235.00$ LFCulvert, CPE Triple Wall, 6" D-5116.00$ LFCulvert, CPE Triple Wall, 8" D-5218.00$ LFCulvert, CPE Triple Wall, 12" D-5327.00$ LFCulvert, CPE Triple Wall, 15" D-5440.00$ LFCulvert, CPE Triple Wall, 18" D-5547.00$ LFCulvert, CPE Triple Wall, 24" D-5664.00$ LFCulvert, CPE Triple Wall, 30" D-5790.00$ LFCulvert, CPE Triple Wall, 36" D-58149.00$ LFCulvert, LCPE, 6"D-5969.00$ LF51935,811.00Culvert, LCPE, 8"D-6083.00$ LF171,411.0024320,169.00Culvert, LCPE, 12"D-6196.00$ LF14413,824.0056854,528.00474,512.00Culvert, LCPE, 15"D-62110.00$ LFCulvert, LCPE, 18"D-63124.00$ LF20725,668.00637,812.00Culvert, LCPE, 24"D-64138.00$ LFCulvert, LCPE, 30"D-65151.00$ LFCulvert, LCPE, 36"D-66165.00$ LFCulvert, LCPE, 48"D-67179.00$ LFCulvert, LCPE, 54"D-68193.00$ LFSUBTOTAL THIS PAGE:13,824.0081,607.0068,304.00(B)(C)(D)(E)Page 9 of 15Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEVersion: 4/1/2024Printed 10/11/2024
CED Permit #:ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostQuantity Remaining (Bond Reduction) (B)(C)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESDRAINAGE (Continued)Culvert, LCPE, 60"D-69206.00$ LFCulvert, LCPE, 72"D-70220.00$ LFCulvert, HDPE, 6"D-7148.00$ LFCulvert, HDPE, 8"D-7260.00$ LFCulvert, HDPE, 12"D-7385.00$ LFCulvert, HDPE, 15"D-74122.00$ LFCulvert, HDPE, 18"D-75158.00$ LFCulvert, HDPE, 24"D-76254.00$ LFCulvert, HDPE, 30"D-77317.00$ LFCulvert, HDPE, 36"D-78380.00$ LFCulvert, HDPE, 48"D-79443.00$ LFCulvert, HDPE, 54"D-80506.00$ LFCulvert, HDPE, 60"D-81570.00$ LFCulvert, HDPE, 72"D-82632.00$ LFPipe, Polypropylene, 6"D-8396.00$ LFPipe, Polypropylene, 8"D-84100.00$ LFPipe, Polypropylene, 12"D-85100.00$ LFPipe, Polypropylene, 15"D-86103.00$ LFPipe, Polypropylene, 18"D-87106.00$ LFPipe, Polypropylene, 24"D-88119.00$ LFPipe, Polypropylene, 30"D-89136.00$ LFPipe, Polypropylene, 36"D-90185.00$ LFPipe, Polypropylene, 48"D-91260.00$ LFPipe, Polypropylene, 54"D-92381.00$ LFPipe, Polypropylene, 60"D-93504.00$ LFPipe, Polypropylene, 72"D-94625.00$ LFCulvert, DI, 6"D-9570.00$ LFCulvert, DI, 8"D-96101.00$ LFCulvert, DI, 12"D-97121.00$ LF576,897.00Culvert, DI, 15"D-98148.00$ LFCulvert, DI, 18"D-99175.00$ LFCulvert, DI, 24"D-100200.00$ LFCulvert, DI, 30"D-101227.00$ LFCulvert, DI, 36"D-102252.00$ LFCulvert, DI, 48"D-103279.00$ LFCulvert, DI, 54"D-104305.00$ LFCulvert, DI, 60"D-105331.00$ LFCulvert, DI, 72"D-106357.00$ LFSUBTOTAL THIS PAGE:6,897.00(B)(C)(D)(E)Page 10 of 15Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEVersion: 4/1/2024Printed 10/11/2024
CED Permit #:ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostQuantity Remaining (Bond Reduction) (B)(C)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESSpecialty Drainage ItemsDitching SD-110.90$ CYFlow Dispersal Trench (1,436 base+)SD-332.00$ LF 147.066,141.92 French Drain (3' depth)SD-430.00$ LF1303,900.00Geotextile, laid in trench, polypropyleneSD-53.40$ SYMid-tank Access Riser, 48" dia, 6' deepSD-62,300.00$ EachPond Overflow SpillwaySD-718.25$ SY40.153732.7947.02858.12Restrictor/Oil Separator, 12"SD-81,320.00$ EachRestrictor/Oil Separator, 15"SD-91,550.00$ EachRestrictor/Oil Separator, 18"SD-101,950.00$ EachRiprap, placedSD-1148.20$ CY321,542.40Tank End Reducer (36" diameter)SD-121,375.00$ EachInfiltration pond testingSD-13143.00$ HRPermeable PavementSD-14Permeable Concrete SidewalkSD-15Culvert, Box __ ft x __ ftSD-16SUBTOTAL SPECIALTY DRAINAGE ITEMS:732.7912,442.44(B)(C)(D)(E)STORMWATER FACILITIES (Include Flow Control and Water Quality Facility Summary Sheet and Sketch)Detention PondSF-187,115.00$ Each 187,115.00Detention TankSF-2Each Detention VaultSF-3Each Infiltration PondSF-4Each Infiltration TankSF-5Each Infiltration VaultSF-6Each Infiltration TrenchesSF-7Each Basic Biofiltration SwaleSF-8Each Wet Biofiltration SwaleSF-9Each WetpondSF-10$27,500Each 127,500.00WetvaultSF-11Each Sand FilterSF-12Each Sand Filter VaultSF-13Each Linear Sand FilterSF-14Each Proprietary FacilitySF-15Each Bioretention FacilitySF-16Each SUBTOTAL STORMWATER FACILITIES:114,615.00(B)(C)(D)(E)Page 11 of 15Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEVersion: 4/1/2024Printed 10/11/2024
CED Permit #:ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostQuantity Remaining (Bond Reduction) (B)(C)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESWRITE-IN-ITEMS (INCLUDE ON-SITE BMPs)STORMWATER POND SIGNWI-1500.00$ EACH1500.00WI-2WI-3WI-4WI-5WI-6WI-7WI-8WI-9WI-10WI-11WI-12WI-13WI-14WI-15SUBTOTAL WRITE-IN ITEMS:500.00DRAINAGE AND STORMWATER FACILITIES SUBTOTAL:31,346.00241,639.79103,653.84SALES TAX @ 10.3%3,228.6424,888.9010,676.35DRAINAGE AND STORMWATER FACILITIES TOTAL:34,574.64266,528.69114,330.18(B) (C) (D) (E)Page 12 of 15Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEVersion: 4/1/2024Printed 10/11/2024
CED Permit #:ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostConnection to Existing WatermainW-13,400.00$ EachDuctile Iron Watermain, CL 52, 4 Inch DiameterW-258.00$ LFDuctile Iron Watermain, CL 52, 6 Inch DiameterW-365.00$ LFDuctile Iron Watermain, CL 52, 8 Inch DiameterW-475.00$ LFDuctile Iron Watermain, CL 52, 10 Inch DiameterW-580.00$ LFDuctile Iron Watermain, CL 52, 12 Inch DiameterW-6145.00$ LFGate Valve, 4 inch DiameterW-71,225.00$ EachGate Valve, 6 inch DiameterW-81,350.00$ EachGate Valve, 8 Inch DiameterW-91,550.00$ EachGate Valve, 10 Inch DiameterW-102,100.00$ EachGate Valve, 12 Inch DiameterW-112,500.00$ EachFire Hydrant AssemblyW-125,000.00$ EachPermanent Blow-Off AssemblyW-131,950.00$ EachAir-Vac Assembly, 2-Inch DiameterW-143,050.00$ EachAir-Vac Assembly, 1-Inch DiameterW-151,725.00$ EachCompound Meter Assembly 3-inch DiameterW-169,200.00$ EachCompound Meter Assembly 4-inch DiameterW-1710,500.00$ EachCompound Meter Assembly 6-inch DiameterW-1811,500.00$ EachPressure Reducing Valve Station 8-inch to 10-inchW-1923,000.00$ EachWATER SUBTOTAL:SALES TAX @ 10.3%WATER TOTAL:(B) (C) (D) (E)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR WATERQuantity Remaining (Bond Reduction) (B)(C)Page 13 of 15Ref 8-H Bond Quantity WorksheetSECTION II.d WATERVersion: 4/1/2024Printed 10/11/2024
CED Permit #:ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostClean OutsSS-11,150.00$ Each1213,800.00Grease Interceptor, 500 gallonSS-29,200.00$ EachGrease Interceptor, 1000 gallonSS-311,500.00$ EachGrease Interceptor, 1500 gallonSS-417,200.00$ EachSide Sewer Pipe, PVC. 4 Inch DiameterSS-592.00$ LFSide Sewer Pipe, PVC. 6 Inch DiameterSS-6110.00$ LF65.897,247.90229.0125,191.1021623,760.00Sewer Pipe, PVC, 8 inch DiameterSS-7120.00$ LF207.924,948.00831.9399,831.60Sewer Pipe, PVC, 12 Inch DiameterSS-8144.00$ LFSewer Pipe, DI, 8 inch DiameterSS-9130.00$ LFSewer Pipe, DI, 12 Inch DiameterSS-10150.00$ LFManhole, 48 Inch DiameterSS-116,900.00$ Each320,700.00320,700.00Manhole, 54 Inch DiameterSS-136,800.00$ EachManhole, 60 Inch DiameterSS-157,600.00$ EachManhole, 72 Inch DiameterSS-1710,600.00$ EachManhole, 96 Inch DiameterSS-1916,000.00$ EachPipe, C-900, 12 Inch DiameterSS-21205.00$ LFOutside DropSS-241,700.00$ LSInside DropSS-251,150.00$ LSSewer Pipe, PVC, ____ Inch DiameterSS-26Lift Station (Entire System)SS-27LSSANITARY SEWER SUBTOTAL:52,895.90145,722.7037,560.00SALES TAX @ 10.3%5,448.2815,009.443,868.68SANITARY SEWER TOTAL:58,344.18160,732.1441,428.68(B) (C) (D) (E)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR SANITARY SEWERQuantity Remaining (Bond Reduction) (B)(C)Page 14 of 15Ref 8-H Bond Quantity WorksheetSECTION II.e SANITARY SEWERVersion: 4/1/2024Printed 10/11/2024
1055 South Grady Way – 6th Floor | Renton, WA 98057 (425) 430-7200Date:Name: Project Name: PE Registration No: CED Plan # (LUA):Firm Name:CED Permit # (C):Firm Address: Site Address:Phone No. Parcel #(s):Email Address:Project Phase: Site Restoration/Erosion Sediment Control Subtotal (a)Existing Right-of-Way Improvements Subtotal (b) (b)355,886.30$ Future Public Improvements Subtotal (c)758,696.60$ Stormwater & Drainage Facilities (Public & Private) Subtotal(d) (d)415,433.51$ (e)(f)Site RestorationExisting Right-of-Way and Storm Drainage ImprovementsMaintenance Bond306,003.28$ Bond Reduction2Construction Permit Bond Amount 3Minimum Bond Amount is $10,000.001 Estimate Only - May involve multiple and variable components, which will be established on an individual basis by Development Engineering.2 The City of Renton allows one request only for bond reduction prior to the maintenance period. Reduction of not more than 70% of the original bond amount, provided that the remaining 30% willcover all remaining items to be constructed. 3 Required Bond Amounts are subject to review and modification by Development Engineering.* Note: The word BOND as used in this document means any financial guarantee acceptable to the City of Renton.** Note: All prices include labor, equipment, materials, overhead, profit, and taxes. EST1((b) + (c) + (d)) x 20%-$ MAINTENANCE BOND */**(after final acceptance of construction)65,918.83$ 355,886.30$ 949,262.96$ 65,918.83$ -$ 415,433.51$ -$ 1,015,181.78$ P (a) x 100%SITE IMPROVEMENT BOND QUANTITY WORKSHEET BOND CALCULATIONS10/11/2024Scott Kaul, PE46972AHBL, Inc.R((b x 150%) + (d x 100%))S(e) x 150% + (f) x 100%Bond Reduction: Existing Right-of-Way Improvements (Quantity Remaining)2Bond Reduction: Stormwater & Drainage Facilities (Quantity Remaining)2T(P +R - S)Prepared by: Project InformationCONSTRUCTION BOND AMOUNT */**(prior to permit issuance)253-383-2422skaul@ahbl.comMaple Highlands 13929 154th Ave. SE & 13818 152nd Ave. SE1463400020 & 1463400021FOR CONSTRUCTION 2215 N. 30th St., Ste. 300, Tacoma, WA 98403Page 15 of 15Ref 8-H Bond Quantity WorksheetSECTION III. BOND WORKSHEETVersion: 4/1/2024Printed 10/11/2024