Storm Drainage Report 001° @ ~~,~~~~ENGINEERING, INCORPORATED
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Storm Drainage Report
Resubmittal#2
Rainier View
Parcel No. 21724420501
9910 Durant St.
Yelm, Washington
Prepared for:
Crest Builders
5516 75'" St. W.
Lakewood, WA 98499
October 15, 2007
BASELINE Job No. 04-159
Prepared by:
Dean H. Zavack, E.I.T.
Reviewed by:
Jerry Waldron, P.E.
"I hereby state that this Storm Drainage Plan for Rainier View has been prepared by me or under my
supervision and meets the standard of care and expertise which is usual and customary in [his community for
professional engineers. I understand [hat City of Yelm does not and will not assume liability for [he
sufficiency, suitability, or performance of drainage facilities prepared by me."
Land Planning & Use • Engineering • Surveying
1910-64'" Avenue West • Tacoma, WA 98466 • (253) 565-4491 • FAX (253) 565-8563 • Seattle (20fi) 824-1205
"Our goal is to exceed your expectations"
rsF~aev ~, ~~~- 0
TABLE OF CONTENTS
SECTION 1 -PROJECT DESCRIPTION 3
SECTION 2 -EXISTING CONDITIONS 3
SECTION 3 -INFILTRATION RATES AND SOILS REPORTS 3
SECTION 4 -WELLS AND SEPTIC SYSTEMS 4
SECTION 5 -FUEL TANKS 4
SECTION 6 -SUB-BASIN DESCRIPTION 4
SECTION 7 - ANALY SIS OF THE 100-YEAR FLOOD 4
SECTION 8 -AESTHETIC CONSIDERATIONS FOR FACILITIES 4
SECTION 9 -FACILITY SIZING AND DOWNSTREAM ANALYSIS 4
Water Quality
Flow Control
Conveyance
5
6
7
SECTION 10 -OTHER PERMITS OR CONDITIONS PLACED ON THIS PROJECT 8
APPENDICES
Appendix A-Vicinity Map, Site Map, and Excerpts of Soil Analysis For Vista Green
and Tahoma Terra
Appendix B -Drainage Calculations and Basin Map
Appendix C -Thurston County Flood Map
2 of 11
SECTION 1 -PROJECT DESCRIPTION
The project proposal is to subdivide one 5.3 +/- acre parcel into 22 lots for future single-
family residences. There was a residential single-family home on-site, which was
recently destroyed by fire. The structure has since been removed. A public street
extending from an adjoining subdivision with aturn-around knuckle is proposed as
access to all 22 lots. The site is zoned Low Density Residential R-4.
The 5.3-acre parcel located at 9910 Durant St. SE in Yelm, WA. The subject property is
located in the SE quarter of Section 24, Township 17 North, Range 1 Easl, and W.M.
See the site map in Appendix A.
The project improvements consist of subdividing the parcel into 22 lots for single-family
residences, a storm tract area, and 56-foot right of way dedication for the public road
improvements and access to the residences. All interior streets shall be improved to
Yelm City Standards for a Local Access Residential, including a 35-foot paved roadway
with two 7-foot parking lanes. Rolled curb and gutter, and a 5-foot concrete sidewalk on
one side. The new public road will be extended through an adjacent development called
Vista Green and will dead end at the northerly end of site where an adjacent
development (Wyndstone) will presumable make a connection to SW Berry Valley Road.
SECTION 2 -EXISTING CONDITIONS
The site currently is a vacant field with a few trees and under story brush. The site
slopes from northeast to southwest at slopes from 1 % to 8%. Vista Green borders the
site to the east and Tahoma Terra is across Durant St. to the west.
Table 1 - Predevelo ed Conditions
Basin Pervious Impervious 2-year, 10-year, 100-year
Descri tion Acres acres Peak rate Peak rate Peak rate
Low growing 5.28 0 0.13 cfs 0.69 cfs 1.53 cfs
brush and
rasslands
SECTION 3 -INFILTRATION RATES AND SOILS REPORTS
Based on Sail Conservation Service (SCS) of Thurston County the soils have been
identified as 110 Spanaway Gravelly, Sandy, Loam which is a Hydrological Soil Group
A. On June 14, 2007, Baseline Engineering sent representatives to verify the soil
characteristics within the storm drainage tract. A. William V. Robinson, P.E., analyzed
the soil at depths approximately 10' below the existing grade at the location of the
infiltration pond. A. William V. Robinson, P.E., confirms that the soils are Spanaway
Gravel with infiltration rates greater than 20 in/hr (3 min/in) and no indication of a water
table 3-feet below the proposed infiltration facility, see soil logs in Appendix A.
Two different geotechnical reports on adjacent sites confirm this soil classification. An
excerpt from the geotechnical analysis from Parnell Engineering from the adjacent
3ofit
development Vista Green and the adjacent development Tahoma Terra is included in
Appendix A.
SECTION 4 -WELLS AND SEPTIC SYSTEMS
There is an existing well on-site that will be abandoned in accordance with the
Department of Ecology (DOE) standards.
SECTION 5 -FUEL TANKS
There are no known fuel tanks located on the site.
SECTION 6 -SUB-BASIN DESCRIPTION
The 22-lot subdivision will have a conveyance, water treatment, and infiltration system
for the public roadway and driveways. The water treatment and retention facilities will be
situated in the dedicated storm tract of the site. The individual homes will each have a
roof downspout infiltration system on its respective lot. It is to our understanding with the
developer, Crest Builders, the homes will have a roof area of 2600 sf per lot. All
stormwater will be retained on-site and disposed of through infiltration.
SECTION 7 -ANALYSIS OF THE 100-YEAR FLOOD
The project site is not located within the 100-year flood plain. See Appendix C for the
FEMA Firm Map.
SECTION 8 -AESTHETIC CONSIDERATIONS FOR FACILITIES
Facilities will be located at the far end of the dedicated storm tract and will not detract
from site aesthetics.
SECTION 9 -FACILITY SIZING AND DOWNSTREAM ANALYSIS
For the proposed 22-lot subdivision water quality, as well as stream bank erosion control
(SBEC), will be designed and constructed for long-term disposal of the stormwater
runoff. Waterworks 6.1.3.5 and the SBUH method were used to size the water quality
and infiltration facilities in accordance to the 1992 DOE Stormwafer Design Manual. See
Appendix B for calculations. The site is graded to flow stormwater toward the road and
into catch basins that will convey the stormwater to the water treatment and quantify
facilities located on Tract A of the site. See Site Map in Appendix A. Each lof will also
contain an individual roof downspout infiltration trench that is designed for 2600 sf of roof
area and will retain the 100-year 24-hour storm event.
4 of 11
Facility 1 contains a permanent pool wet pond water treatment facility. Facility 1 treats
stormwater from the pollution generating surfaces of the driveways and public street.
See Appendix B for site description and drainage calculations.
Waterworks 6.1.3.5 and the SBUH method were used to size the water quality and
infiltration facilities. See Appendix B for site description and drainage calculations. The
wet pond is designed to treat and contain stormwater flows up to the 6-month 24-hour
storm. The 6-month 24-hour storm is defined by 1992 DOE stormwater Manual as 64%
of the 2-year 24-hour storm. stormwater flows greater than the 6-month 24-hour storm
will enter an overflow and flow directly into the overtlow infiltration pond. The infiltration
pond is designed to contain the 100-year 24-hour storm. By inspection the peak flow
rates of the 100-year, 7-day storm are lower than the peak flows generated by the 100-
year, 24-hour storm, therefore the 100-year, 24-hour storm will govern the design of the
overflow infiltration pond. Flows greater than the 100-year 24-hour storm will enter an
emergency overtlow designed to drain into the drainage course along Durant Street,
which will become a paved pedestrian walkway.
Rainier View Developed Site Flows
Storm ID (24-hour) Impervious Area*
acres Pervious Area
acres SBUH Calculated
Flows
6-month 1.24 2.77 0.33 cfs
2- ear 1.24 2.77 0.63 cfs
10- ear 1.24 2.77 1.20 cfs
100- ear 1.24 2.77 1.85 cfs
*Roof area not included since roofs stormwater flows into individual roof downspouts.
Water Quality
Facility 1 -Wet Pond:
Water treatment for Rainier View will be provided by a permanent pool, two-cell wet
pond to remove sediments (TSS) and free oil (TPH) from stormwater runoff before
entering an overtlow infiltration pond. The pond will have a geotextile liner to prevent
infiltration into the Spanaway Gravel native soils, which have a high infiltration rate. The
pond will be built to minimum 1992 DOE Standards and shall incorporate two cells. The
wet pond cells are separated by a berm with 4 to 1 slopes that is submerged 1' below
the design water surface elevation of 341.0. The total wet pond volume is designed to
contain the 6-month 24-hour storm as was discussed with James E. Gibson, City of
Yelm Development Services Engineer, on 1/22 to comply with 1992 DOE design
standards. stormwater flows above the design water surface elevation of 341.0 will flow
through a 12-inch spillway pipe directly into the overflow infiltration pond. This pipe will
help prevent floatables from entering the infiltration pond, which is consistent with typical
spillway berms of this design. The overflow infltration pond was sized by Waterworks
6.1.3.5 to contain the 100-year 24-hour storm event. The first cell of the permanent pool
wet pond is designed with one 4 to 1 side slopes and 3 to 1 side slopes to provide
maintenance access. Cell 1 of the wet pond is designed with one-foot of sediment
storage, 4-feet of active storage, and 1-foot of emergency freeboard. Cell 2 has 5-feet
S ofll
of active storage and two 4 to 1 slopes to allow maintenance access between all three
pond cells.
Facility 1: Pretreatment Permanent Pool Wet Pond
Design Storm ~ SBUH Calculated S H Calculated Actual Wet Depth of
ID Flow Volume Pond Active Wet Pond
Volume before @ overflow
overflow' _
6-month 24- 0.33 cfs 6246 cf 14,507 cf 5 feet
Hour
*Not including bottom 1-foot of cell 1 of pond intended for sediment storage.
Flows generated from roofs will enter individual roof downspout infiltration trenches and
will not require water quality because of the non-pollution generating surtaces of the
roofs.
Flow Control
Facility 2 -Infiltration Pond
The runoff from driveways, landscaping, and the public roadway will be collected with
catch basins and conveyed through CPEP pipe materials to a two cell wet pond
treatment facility and then into an oveflow infiltration pond. The water quality
permanent pool two-cell wet pond is sized to contain the volume of the 6-month 24-hour
storm. The 6-month 24-hour storm by 1992 DOE Stormwater Management Manual for
Puget Sound is defined as 64% of the 2-year 24-hour storm. Storms exceeding the 6-
monlh, 24-hour flow rate will enter the overflow infiltration pond through a with a 12-inch
pipe that runs through the spillway berm linking the wet pond with the infiltration pond.
The infiltration pond contains 1-foot of freeboard above the 100-year 24-hour storm
water level far stability. The infiltration pond contains 29% additional volume capacity for
emergency overflow volume. Storms greater than the 100-year 24-hour storm will enter
the infiltration pond emergency overflow which is set at % foot below maximum free
board height and enter the drainage course along Durant St. SE. The infiltration pond
has a draw down time of less than 48 hours as per 1992 DOE standards see Appendix B
for calculations.
6 of l I
Facility 2: Overflow Infiltration Pond (Calculated Dimensions are 62' by 21.67'-
bottom dimensions with 3 to 1 slopes. Active Storage Depth = 3-feet)
Design Infiltration SBUH SBUH Design Actual Emergenc~
Storm ID Rate Calculated Calculated Infiltration ' Pond Overflow '
Developed Active Rate Volume Volume
100-year Volume Capacity
Flows before
overflow
100- 20 in / hr 1.85 cfs 5493 cf 20 inches / 7100 cf 29%
' year 24- hour
Hour
"1-foot of freeboard not included in this volume calculation.
Wet Pond volume not included in this volume calculation.
The infiltration rate used for the preliminary sizing of the overflow infiltration pond is
assumed 3 min per inch or 20 inches per hour based from Geotechnical Reports on
8/24/05 by Parnell Engineering from the adjacent site Vista Green. An excerpt from this
report in Appendix A. This infiltration rate was cross-referenced by examining the
Geotechnical Report from Tahoma Terra, another adjacent site across Durant Street.
This report, also from Parnell Engineering, was dated 1/19/05 and an excerpt of this
report is included in Appendix A. The Thurston County SCS also verifies this soil
classification, see Appendix A. This infiltration rate of 3 min per inch infiltration rate will
be verified for Rainier View with a soil analysis by A. William V. Robinson, P.E. from
Baseline Engineering at the time of construction of the infiltration pond.
Roof Downspout Infiltration Trenches:
Flow generated from roofs will enter individual roof downspout infiltration trenches and
not enter the water quality infiltration pond because the non-pollution generating
surfaces of the roofs will not require treatment. Each lot will contain an individual roof
down spout infiltration trench sized for 2,600 sf of roof area. The individual roof
downspout infiltration trenches will be sized for the 100-year 24-hour storm.
Individual Roof Downspout Infiltration Trench Summary (2600 sf Roof Areal
Design Infiltration SBUH SBUH Actual Actual
Storm ID Rate Calculated Calculated Trench Size Active
100-year Active Volume Volume*
Flows
100-year 24- 20 in / hr .058 cfs 50.8 cf 3' by 19' by 51.3 cf
Hour 3'dee
"Trench contains washed rack with 30% Voids. Volume contained in voids in rocks.
Convevance
The conveyance designed is based on the 100-year 24-hour storm using flows
calculated from the Santa Barbara Unit Hydrograph Method (SBUH) and Waterworks
6.1.3.5 as shown in Calculations in Appendix B.
7of 11
The runoff from the roadway and driveways will be collected using concrete rolled curb
and gutter, catch basins, and CPEP or PVC pipe materials. Storm drainage from the
public roadways will be conveyed to the water quality/infiltration pond to remove total
suspended solids (TSS) and free oil (TPH) from the stormwater before entering the
overflow infiltration pond. Trapped oil contaminates and sediments can then be
removed from the bottom of wet pond cell 1 at regular service intervals.
Downstream Analysis
All stormwater is to be retained on-site for stormwater flows up to the 100-year 24-hour
storm. A downstream analysis was deemed unnecessary since all stormwater is to be
retained on-site.
SECTION 10 -OTHER PERMITS OR CONDITIONS PLACED ON THIS PROJECT
An NPDES permit and site development permit will be required. No other permits are
anticipated for this project as it is not affecting any existing wetlands and does not
discharge into a surface water body. A 10-foot setback from all property lines and
easement are required for stormwater facilities. Sewer will be provided by the City of
Yelm through a S.T.E.P. system and will not interfere with Storm Drainage Facilities.
8of11
APPENDIX A-
VICINITY MAP, SITE PLAN & EXCERPTS OF SOIL ANALYSIS
FROM VISTA GREEN AND TAHOMA TERRA
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June 15, 2007
Soil Log information for
Rainier View Estates
Site Address: 9910 Durant Street S.E.
Yelm, WA 98597
BASELINE Engineering Job No. 04-159
Soil Loa #1
Located in the Southwest corner of site 20' East of fence 27' North of fence
0' - 2' Black loamy gravely sand with humus
2' - 10' Brown medium sandy gravel with up to 8" cobles and a 2" pea gravel lens at
T and roots to 10'
10' - 11 %' Coarse gravely sand No Groundwater
Sail Loa #2
Located in the Southwest corner of site 25' North of fence & 120' East of fence
0' - 2' Black loamy gravely sand with humus
2' - 10 Yz' Brown sandy gravel with three - 2" pea gravel lens
10 % ' - 11 Yz' Dark brown coarse sandy gravel - No Groundwater
Recommended Design Infiltration Rate: 2 minutes per inch
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Lantl Planning 8 Use Engineering Surveying
1910-64Th Avenue West • Tacoma, WA 98466 (253) 565-4491 Fax (253) 565-6563 Sealile (206) 824-1205
"The industry starts here"
EXPIRES 8-27-OB
WASHINGTON - SHEET NUMBER 24
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CHII9ICAL PAOPERTI£S OP THE SOILS -Continued
TABLE 15.--p~SICAL A3ID xos on ~
Soil { ShxlNc-swell factors i0rgan lc
Available ~T~ matter
'~ Permeability ~ water capacity tl reactions potential ~ X T
{Depth's Clay t
Soil name and ~
map symbol I=in gH '
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LUBBESMEYER LONGMIRE PLAT
Soils Report For Drainage Purposes
Site Address: 15132 Longmire Street Yelm, Wa. 98597
Tax Parcel Number: 21724420800
Prepared For: Olympic Engineering
] 252 Devon Loop NE
Olympia, WA 98506
(360) 870-2561
Contact: Chris Merritt, P.E.
Prepared By: Parnell Engineering
10623 Hunters Lane S.E.
Olympia, WA 98513
(360) 491-3243 Fax (360) 491-3243
Contact: William Parnell, P.E.
PE
PARNELL ENGINEERING
V 1 j~"Gl U` ~'c'C ~}
SOIL EVALUATION REPORT
FORM 1: GENERAL SITE INFORMATION
PROJECT TITLE Lubbesmeyer Longmire Plat SHEET_ 1 OF 1
PROJECT NO. :05134 DATE: 8/24/05
PREPARED BV :William Parnell, P.E.
1. SITE ADDRESS 15132 Longmire Street Yelm, Wa. 98597
TAX PARCEL NUMBER: 21724420800
2. PROJECT DESCRIPTION: Create a 201ot resitlential subdivision.
3. SITE DESCRIPTION: The 4.7 acre projeM site is currently occupied by a single residential tlwelling antl
two outbuildings. Site relief is nearly level. The southern 180' of this parcel slopes to the south at a 1%slope.
The remaining project site slopes to the north at a 1-2% slope Elevations range from a high of 353 R to a
low of 346 ft. at the northeast property corner. There are no site distinguishing features other than an existing
tlomestic well. Site vegetation consists of uncropped field grasses on the majority of the site, with maintained
grass lawn and landscaping atljacent to the existing house. The project site is hounded by residential
property to the north, east and west, and by Longmire Street SE to the south. On-site sails are swell-drained
Spanaway series formed in glacial outwash.
4. SUMMARY OF SOILS WORK PERFORMED: Two test pits were excavated by backhoe to a tlepth of
152" below the existing grade. Soils were inspectetl by entering antl visually logging each test pR to a depth
of four feet. Soils heyond four feet were inspectetl by examining backhoe tailings. One double ring infiltration
test was completed in test pit #7 at 96" below the existing grade. Test pit soil log data sheets and a double
ring infiltration test result are included in this report.
5. ADDITIONAL SOILS WORK RECOMMENDED: Atlditional sails work should not be necessary unless
tlrainage infltraticn facilities are located outsitle the general area encompassed by the soil test pits.
6. FINDINGS: TheNaturalResourceCOnservatianServicesailsurveyforThurstanCOUntymappedthecn-
sitesoilsasaSpanawayGravellySandyLoam(110). The twotest pits confirmed the Spanaway designation
generally profiling a gravelly fne sandy loam surface soil overlying an extremely gravelly 8 cobbley coarse-
medium santlsubstratum. The substratum gravels and santls were slightly loose. Winter water table was not
present and indicators were not visible. A douhle ring infltration test completed at 98" below the existing
gratle revealed an infiltration rate of 46.5 in/hr.
7. RECOMMENDATIONS: The Spanaway soil series is a somewhat excessively tlrained soil that formed in
gravelly glacial outwash Infiltration rates are generally rapid in the substratum soils. The specifed
substratum C-horizon soils should be targetetl far all drainage infltration facilities as noted in the attached
soil log data sheets. A design infiltration rate of 20 in/hr or less would be appropriate far these targeted soils.
During construction, care must be taken to prevent the erasion of exposed soils. Drainage facility infltration
surtaces must be properly protected from contamination by the fne-grained upper horizon sails and from
compaMion by construction site activities. Sails not properly protected will cause drainage infltmtion facilgies
to prematurely fail.
I hereby certify that I prepared this report, and conductetl or supervised [he performance of related work. I
cedify that I am qualifietl to do this work. I represent my work to be complete an accurate within the bounds
of uncertainty inherent to the practice of s its science, and to be suitable far its intended use.
SIGNED: ~d 1~.. , ~c.4-.:L.e~n
DATE ~/G ~~-'S
_ -~7_ __
v.~ D[rna ~P_9°~r~
SOIL EVALUATION REPORT
FORM 1: GENERAL SITE INFORMATION
PROJECT N0.~05100 an~ci: i yr 1
PREPARED BY: William Parnell. P.E. DATE: 1/19105
TPN: 21724310100
_ _ __.__..__. ___,...._..,~~ ..,.,~ a„ e~~~,,,a~cu wauway. uaury antl
landscaping improvements.
3. SITE DESCRIPTION: The project site is currently occupied by one residential building and several
outbuildings centrally located an the parcel. Site relief is relatively flat with no distinguishing features.
Vegetation consists of actively used agricultural pasture grasses. The project site is bounded by Berry
Valley Road to the north. Longmire SVeet SE [c the south, residentlal to the east and undeveloped
property to the west. On-site sails are well drained and formed in glacial outwash.
4. SUMMARY OF SOILS WORK PERFORMED: Thirteen test pits were excavated by hackhoe to a
maximum depth of 1 BO" below existing grade. Soils were inspected by entering and visually lagging
each test pit to a depth of four feet. Sails beyond four feet were inspected 6y examining hackhoe
tailings. Falling head percolation tests were completed in test pits #2, 5, 7, 9, 11 and 13 at a depth of
60" below the existing grade. Test pit sail log data sheets and percolation lest results are included in
this report.
5. ADDITIONAL SOILS WORK RECOMMENDED: Additional soils work should not he necessary
unless drainage inTiltratlon facilities are located outside the general area encompassed by the soil test
pits.
6. FINDINGS: The National Resource Conservation Service o(Thurstan County mapped the on-site
sails as a Spanaway Gravelly Sandy Loam (110). All test pits confrm this designatlon. All test pits
generally revealed gravelly fne sandy loam surface sails. overlying an exVemely gravelly and cobhley
coarse sand substratum. Substratum soils were moderately loose with no fines present. Winter water
table was not present in any test pits. Falling head percolation tests were completed revealing the
following infltration rates: Test pit #2 - 2160 in/hr, #5 - 144 in/hr, #7 - 188 in/hr, # 9 - 617 in/hr.
#11 - 360 in/hr, #13 - 68.5 in/hr. Tests were completed utilizing a 6" diameter PVC pipe [o prevent
sidewall collapse.
v<ry meureo son ma[
formed in glacial outwash. InflVation rates are generally rapid in the substratum soils. The substratum
soils should he targeted for all drainage infiltration (acilities. A design infiltration rate of 20 in/hr or less
would be appropriate for all targeted C-horizon sails as recommended in the attached sail lag
information sheets.
During construction, care must be taken to prevent erosion of exposed soils. Drainage facility
infilhation surtaces must he properly protected from contamination by the fine-grained upper horizon
sails and From compaction by site construction activities Soils not properly protected will cause
drainage infiltration facilities to prematurely fail.
• ---• -~- ~ r•-r-~~~ ,~~~~ ~<N,,, ~, anti concuc[eo or supervisetl the performance of related
work. I cenify that I am qualified to do this work. I represent my work to be complete an accurate within
the bounds of uncertainty inherent In_ih practice of sails science, and to be suitable far ils intended
use. ~/~ ~
SIGNED: [ r [ Gki ~ c~~~ ~ y 1 ~• ~
l
DATE: ~~4~'
i:::Y i r
,'.. -~~
`;
A; `.
APPENDIX B -BASIN MAP AND DRAINAGE CALCULATIONS
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Wa[erWOrks HMS Repod Fritlay, February i6, 2007
Project: 041591n1i1 Pontl2 P 1
Rainier View 04-159
Yelm, WA per 1992 DOE Stormwater Management Manual Standards
Predeveloped Flows For Rainier View
Project Precips
[2 yr] 2.00 in
[5 yr] 2.50 in
[10 yr] 3.00 in
[25 yr] 3.50 in
[100 yr] 4.00 in
[6 mo] 1.28 in
Drainage Area: predeveloped
Hyd Method: SBUH Hyd
Peak Factor: 484.00
Storm Dur 24.00 hrs
Area CN
Pervious 5.2800 ac 74.OC
Impervious 0.0000 ac 0.00
Total 5.2800 ac
Supporting Data:
Pervious CN Data:
low growing brush & grasslands 74.00
Pervious TC Data:
Flow type: Description:
Loss Method: SCS CN Number
SCS Abs: 0.20
TC
0.17 hrs
0.00 hrs
5.2800 ac
Length: Slope: Coeff: Travel Time
440.00 ft 2.00% 5.0000 10 37 min
6 mo Flow Time Volume
Summary: 0.0390 cfs 22.00 hrs 1560.14 cf - 0.0358 acft
2 yr Flow Time Volume
Summary: 0.1300 cfs 9.00 hrs 6700.66 cf - 0.1538 acft
10 yr Flow Time Volume
Summary: 0.6900 cfs 8.00 hrs 17406.63 cf - 0.3996 acft
25 yr Flow Time Volume
Summary: 1.0916 cfs 8.00 hrs 23762.31 cf - 0.5455 acft
100 yr Flow Time Volume
Summary: 1.5336 cfs 8.00 hrs 30592.76 cf - 0.7023 acft
Baseline Engineering Inc.
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Waterworks HMS Report Thursday, January 11, 20W
Project: 041591nN Pantl2 P 1
Developed Flows for Rainier View 04-159
Yelm, WA per 1992 DOE Stormwater Management Manual Standards
Project Precips
[2 yr] 2.00 in
[5 yr] 2.50 in
[70 yr] 3.00 in
[25 yr] 3.50 in
[100 yr] 4.00 in
[6 mo] 1.28 in (6-month = 64 % of 2-year for 1992 DOE)
Drainage Area: Dev
Hyd Method: SBUH Hyd
Peak Factor: 484.00
Storm Dur 24.00 hrs
Area CN
Pervious 2.7700 ac 78.00
Impervious 1.2400 ac 98.00
Total 4.0100 ac
Supporting Data:
Pervious CN Data:
Landscaping 78.00
Impervious CN Data:
Road, driveways, pond area 98.00
shared driveway for lots S, 11 98.00
Pervious TC Data:
Flow type: Description:
Sheet Flow down landscaping
Sheet flow down road
Shallow flow down road
Channel conveyance through N-12 pipe
Impervious TC Data:
Flow type: Description:
Sheet Flow down driveway
Sheet flow down road to CB
Loss Method: SCS CN Number
SCS Abs: 0.20
TC
0.50 hrs
0.10 hrs
2.7700 ac
1.1400 ac
0.1000 ac
Length: Slope: Coeff: Travel Time
225.00 ft 1.50 % 0.1500 26.60 min
75.00 ft 1.00% 0.0110 1.61 min
130.00 h 1.00 % 27.0000 0.80 min
250.00 ff 1.00 % 42.0000 0.99 min
Length: Slope: Coeff: Travel Time
195.00 ff 2.00 % 0.0110 2.61 min
105.00 ft 1.00 % 0.0110 2.10 min
Channel conve ante with N-12 i e mat. 250.00 ft 1.00 % 42.0000 0.99 min
6 mo Flow Time Volume
Summary: 0.3316 cfs 8.00 hrs 6245.92 cf - 0.1434 acff
2 yr Flaw Time Volume
Summary: 0.6261 cfs 8.00 hrs 12856.27 cf- 0.2951 acf[
10 yr Flow Time Volume
Summary: 1.2012 cfs 8.00 hrs 23809.96 cf - 0.5466 acft
100 yr Flow Time Volume
Summary: 1.8526 cfs 8.00 hrs 35919.42 cf - 0.8246 acff ~
Baseline Engineering Inc.
Waterworks HMS Report Thurstlay, January 11, 2007
Project 041591nfl POntl2 p 1
Rainier View 04-159
(Calculated Infiltration Pond Size 28' by 41' with 3.00 h: 1v and 3-foot deep)
( 103r
Project Precips a
12 Yrl 2.00 in ]-r
[5 yr] 2.50 in
[10 yr] 3.00 in 3[n. ],V - ~
100-year 24-hour 3 Frc<~r0
[25 yr] 3.50 in storm ~~
[100 yr] 4.00 in _ e-~ [~a
[6 mo] 1.28 in ~ C&, ~~
RLPCOMPUTE [Routing] SUMMARY
100 yr Match O: 0.00 cfs Peak Out O: 0.53 cfs -Peak Stg: 102.9 5 ft -Active Vol: 0.13 acft
Summary Report of all RLPooI Data
BASLIST2
[Dev] Using [TYPEIA] As [100 yr]
LSTEND
BasinlD Peak O Peak T Peak Vol Area Method Raintype
Event
------- (cfs) (hrs) (ac-ft) ac !Loss
Dev 1.85 8.00 0.8246 4.01 SBUHISCS TYPEIA 100 yr
BASLIST [TYPEIA] AS [100 yr] DETAILED
[Dev]
Drainage Area: Dev
Hyd Method: SBUH Hyd
Peak Factor: 484.00
Storm Dur 24.00 hrs
Area CN
Pervious 2.7700 ac 78.00
Impervious 1.2400 ac 98.00
Total 4.0100 ac
Supporting Data:
Pervious CN Data:
Landscaping 78.00
Impervious CN Data:
Road, driveways, pond area 98.00
shared driveway for lots 8, 11 98.00
Pervious TC Data:
Flow type: Description:
Sheet flow down landscaping
Sheet Flow down road
Shallow flow down road
Channel conveyance through N-12 pipe
Impervious TC Data:
Flow type: Description:
Sheet flow down driveway
Sheet flow down road [o CB
Loss Method: SCS CN Number
SCS Abs: 0.20
TC
0.50 hrs
0.10 hrs
2.7700 ac
1.1400 ac
0.1000 ac
Length: Slope: Coeff: Travel Time
225.00 ft 1.50 % 0.1500 26.60 min
75.OOft 1.00% 0.0110 1.61 min
130.00 ft 1.00 % 27.0000 0.80 min
250.00 ft 1.00 % 42.0000 0.99 min
Length: Slope: Coeff: Travel Time
195.00 ft 2.00°/ 0.0110 2.61 min
tO5.00ft 1.00% 0.0110 2.10 min
_ Channel conveyance with N-12 pipe mat 250.00 ft 1.00 % 42.0000 0.99 min
100 yr Flow Time Volume
Summary: 1.8526 cfs 8.00 hrs 35919.42 cF- 0 8246 acft
Baseline Engineering Inc.
WaterWOrks HMS Repoli Thursday. January 11, 200]
Protect: 041591nN Pontl2 p p
HYDLIST SUMMARY
[t OOyr out]
LSTEND
HydID Peak O Peak T Peak Vol Cont Area
------- (cfs) (hrs) (ac-ft) (ac)
1DOyr enc Ds3 7.n o.a2s1 4.omD
STORLIST
[Infil Pand]
LSTEND
Node ID: Infil Pond
Desc: Infltration Pond
Start EI: 100.0000 ft Max EI: 103.0000 ft
Contrib Basin: Contrib Hyd:
Lenqth ss1 ss2 Width ss3 ss4
41.0000ft 3.OOh:1v
Boftom area 3.OOh:iv
only with infltration 28.0000ft 3.OOh:iv 3.OOh:1v
DISCHLIST
[Infiltration]
LSTEND
Control Structure ID: Infiltration -Infiltration control structure
Descrip: Multiple Orifice
Start EI Max EI Increment
100.0000 ft 103.0000 ft 0.10
Infil: 20.00 in/hr Multiplier: 1.00
STORTABLE TABLE
[loft Pand]
LSTEND
Stage•Storge Table for node Infil Pond
Stage Vol Vol
(ft) (cf) (ac-ft)
100.00 0.00 0.0000
100.10 116.88 0.002]
100.20 23].98 0.0055
100.30 363.35 0.0083
100.40 493.09 0.0113
1 oDSD sz7.zs 9.9144
19oso 7ss.91 o.ans
100]0 909.15 0.0209
100.80 105].02 0.0243
100.90 1209.62 0.02]8
101.00 1367.00 0.0314
101.10 152924 0.0351
101.20 1696.42 0.0389
101.30 1668.59 0.0429
101.40 2045.85 0.04]0
101.50 2228.25 0.0512
101.60 2415.87 0.0555
Stage Vol Vol
(ft) (cf) (ac-ft)
101.]0 2608 .]9 0.0599
101.80 28W .Ofi 0.0644
101.90 3010. ]8 9.9fi91
102.00 3220. 00 0.0]39
102.10 3434. 80 0.0789
19z.zo 3sss. zs o.o63s
102.30 3881 43 D.0891
102.40 4113. 41 0.0944
102.50 4351. 25 0.0999
702.60 4595. 03 0.1055
102.70 4844. 83 0.1112
102.80 5100 ]0 0.1171
102.90 5362. ]4 0.1231
103.00 5fi31. 00 0.1293
Baseline
WaterWaMS HMS Report Monday, January 22, 2097
Protect. 041591nf1 Pontl2 Pa e 1
Wet Pond For Rainier View 04-159
Yelm, WA per 1992 DOE Stormwater Management Manual Standards
+oo of P;Pf ~xery~
Project Precips
[2 yr] 2.00 in =~
[s yr] zsoin 3h',1v celll 4~ -4h;1v- Celle 5' -~
rr~r~~,f,n.,
[10 yr] 3.00 in
[25 yr] 3.50 in ~~ 1'`.e~'irrcxi '
[100 yr] 4.00 in Sfnr+yp
[fi mo] 1.28 in (6-month = 64 % of 2-year far 1992 DOE)
Drainage Area: Dev
Hyd Method: SBUH Hyd
Peak Factor: 484.00
Storm Dur 24.00 hrs
Area CN
Pervious 2.7700 ac 78.00
Impervious 1.2400 ac 98.00
Total 4.0100 ac
Supporting Data:
Pervious CN Data:
Landscaping 78.00
Impervious CN Data:
Road, driveways, pond area 98.00
shared driveway for lots 8, 11 98.00
Pervious TC Data:
Flow type: Description:
Sheet flow down landscaping
Sheet flow down road
Shallow flow down road
Channel conveyance through N-12 pipe
Impervious TC Data:
Flow type: Description:
Sheet flow down driveway
Sheet flow down road to CB
Channel conveyance with N-12 pipe mat.
6 mo Flow Time
Summary: 0.3316 cfs 8.00 hrs
Loss Method: SCS CN Number
SCS Abs: 0.20
TC
0.50 hrs
0.1 o nrs
2.7700 ac
1.1400 ac
0.1000 ac
Length: Slope: Coeff: Travel Time
225.00 R 1.50 % 0.1500 26.60 min
75.00 R 1.00 % 0.0110 1.61 min
130.00 ft 1.00 % 27.0000 0.80 min
250.00 ft 1.00 % 42.0000 0.99 min
Length: Slope: Coeff: Travel Time
195.00 ft 2.00 % 0.0110 2.61 min
105.00 ft 1.00 % 0.0110 2.10 min
250.00 ft 1.00 % 42.0000 0.99 min
Volume
6245.92 cf - 0.1434 acH
1992 DOE Requires Wet pond to Contain Volume of 6-month 24-Hour Storm
Pond Volume should have minimum 6245.9 cf of volume using SBUH method for 6-month 24-
hour storm. Actual Pond size will have a minimum volume of 14,507 cf which gives a Factor of
Safety (FS) of 2.3.
WaterVJOrks HMS Report Wetlnesday, January iD, 2001
Project: 041591nf1 Pond2 P 1
Individual Roof Downspouts For 2600 sf Roof Area
Trench size (3' by 19' by 3' Deep)
Rainier View 04-159
Yelm, WA per 1992 DOE Stormwater Management Manual Standards
Project Precips
[2 Yr] 2.00 in
[5 yr] 2.50 in 30% Voids in
[70 yr] 3.00 in ,
[25 yr] 3.50 in p
[100 yr] 4.00 in 3 Washed Rack rerkrdtr~
[6 ma] 1.28 in
~~
~ ~~
RLPCOMPUTE [roof routing] SUMMARY ~~
100 yr Match O: 0.00 cfs Peak Out O: 0.03 cfs -Peak Slg: 102.97 ft -Active Vol: 50.77 cf
Summary Report of all RLPooI Data
BASLI5T2
[Single Roof] Using [TYPE1A] As [100 yr]
LSTEND
BasinlD Peak O Peak T Peak Val Area Method Raintype
Event
------- (cis) (hrs) (ac-ft) ac /Loss
Single ROOf 0.06 ].B3 0.0188 0.06 SBUH/SCS TYPEIA 100 yr
BASLIST [rYPE1A] AS [100 yr] DETAILED
[Single Roof)
LSTEND
Drainage Area: Single Roof
Hyd Method: SBUH Hyd Loss Method: SCS CN Number
Peak Factor: 484.00 SCS Abs: 0.20
Storm Dur 24.00 hrs
Area CN TC
Pervious 0.0000 ac 0.00 0.00 hrs
Impervious 0.0600 ac 98.00 0.01 hrs
Total 0.0600 ac
Supporting Data:
Impervious CN Data:
2500 sf per home 98.00 0.0600 ac
Impervious TC Data:
Flow type: Description: Length: Slope: Coeff: Travel Time
Shee[ flow dawn roof 30.00 ft 3.00% 0.0110 0.50 min
Channel N-12 pipe conveyance [o trench 40.00 ft 1.00 % 42.0000 0.16 min
TC of 0.66 min < 5 min, program will use a tc of 5 min in computations.
100 yr Flow Time Volume
Summary: 0.0578 cfs 7.83 hrs 820.10 cf - 0.01 BS acft
Inc.
Wa[erWorks HMS Repotl Wetlnesday, January 10, 200]
Project: 041591n01 POntl2 P 2
STORLIST
[roof trench]
LSTEND
Node ID: roof trench
Desc: Infiltration Pond
Start EI: 100.0000 ft Max EI: 103.0000 ft
Contrib Basin: Contrib HYd: _
Length Width Void Ratio
19.0000 ft 3.0000 ft 30.00
Bottom area only with infiltration
DISCHLIST
(Infltration]
LSTEND
Control Structure ID: Infiltration -Infiltration control structure
Descrip: Multiple Orifice
Start EI Max EI Increment
100.0000 ft 103.0000 ft 0.10
Infil: 20.00 in/hr Multiplier: 1.00
STORTABLE TABLE
[roof trench]
LSTEND
Stage-Storge Table for node roof trench
Stage Vol Vol
(f[) (cf) (ac-ft)
1 oa.oo o.oo o.ooao
1no.1o 1.]i o.popo
100.20 3.42 0.0001
100.30 5.13 0.0001
1 po.ao s.64 o.ppoz
loo so ass o.ooaz
100.60 10.26 0.0002
100.]0 11.B] O.W03
10p.60 13.68 0.0003
100.90 15.39 0.0004
101.00 nm o.oooa
m1.m 1s.a1 o.oop4
1o1.zo zpsz o.ppos
101.30 22.23 0.0005
1 p1.40 23.94 p.p00s
101.50 25.6s 0.0006
101.fi0 2].36 0.0006
Stage Val Vol
(ft) (cf) (ac-ft)
101.]0 zs.o] 0.a0w
1n1sp 3o.]e o.oao]
101.90 32.49 O.OOW
1nz.0p 3a.zp o.opoa
1nz.1a 3ss1 o.o0oa
102.20 3].62 0.0009
102.30 39.33 0.0009
102.40 41.04 0.0009
1 p2.50 42.]5 0.0010
102.60 44.46 00010
102.]0 4s.n 0.0011
1nz.eo azas 0.oa11
102.90 49.59 0.0011
103.00 51.30 0.0012
Engineering Inc.
MANNING'S EQUATION FOR OPEN CHANNEL FLON,
12" CIRCULAR PIPE CAPACITY
z I
Q- 1.49AR1S~
Input Values
d=diameter of pipe 1.00 ft
h = height of flow 0.90 ft
S =longitudinal slope 0.005 fUft
n =roughness coefficien 0.014
Calculated Variables
V =Velocity 3.36 tps
A -Area
P =Perimeter
WA =Wetted Area 0.745
WP =Wetted Perimeter 2.498 ft
= y rau is a ws
ercent u ~
= uan ity o ow c s
Minimum pipe slope
Check for Capacity: 100-year 24-hour Storm Flow = 1.86 cfs
2.50 cfe > 1. a6 cfa Hae Capacity
Infiltration Pond 48-hour Drawdown Time Requirement
Ta.~waow~ _ (Pond Volume)/ [Bottom Area x Infiltration Rate x (1 ft/12 inches)]
'fa,ewa~w~ -= 5493 cf / [962 sf x 20 inches / hour x (1 ft/12 inches) ]
Taawaow~ = 3.42 hours
STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN
APPENDIE AIII-1.1
ISOPLWIAL NAPS FOR DBSION STORMS
Included in this appendix are the 2, 10 entl 100-year, 24-hour design storm and mean
annual precipit nt ion Seopluvial maps for the Puget Sound basin. Theee have been taken
from NOAH Atlas 2 "Precipitation - Frequency Atlas o£ the Weetern United States, Volume
IX, Washington.
III-1- 3 FRBRUARY, 1992
Zvi ' b. ~:y.
ETORMWATER MANAGEMENT MANUAL FOR THE PUCET SOUND BASIN
III-1-44 FEBRUARY, 39 2
STOAMWATEA MANAGEMENT MANUAL FOR THE PUGET EOUNO BASIN
ate
•il-1 as eEBRUARY, 1992
I ,~a~
STOAMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND HASIN
124 123
r_..
IS_~
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J \
0
~,-
1 Gn
1 ~ "~
\ I ffl100Y HA~CiN •POfli $I PNI''
0
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ao
WASHINGTON ~ '°
~'~, 10 0 10 10 JO 10 ~ 1
MILES I 10I
\~'
Figure 30 1
' ISOPLUVIALS F 100~Yfl 24~HR PRECIPITgTION
IN TENTHS OF N INCH
I24 123-_-
„ __ ~ ---~ `~S~#e
ATLAS Y, Volume I%
m AV U S gpphmmt of Crlnmu..
Ili
BTORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN
Table III-1.3 ECE Weet ern Washington Runoff Curve Numbers
(Published by sC8 1n 1982) Runoff curve numbers for selected agricultural,
suburban and urban
LAND U8E DESCRIPTION CURVE NUMBERS BY
H OLOG IC SOIL GROUP
A B C D
Cultivated land 1): winter condition 86 91 94 95
Hovntaln open areas: low growlnq brush 6 grasslands 74 82 S9 92
Meadow or pasture: 65 78 85 89
Wood or forest land: . undisturbed 42 64 76 81
Wood or forest land: young second growth or brush 55 ]2 81 86
orchard: with cover cro 81 88 92 94
Open spaces, lawns, parka, golf courses, cemeteries,
landscaping.
Good condition: grass cover on [759 of the 68 80 86 90
area
Fair condition: grass cover on 50-759 of 7] 85 90 92
the area
Gravel roads 6 parki ng lots: ]6 85 89 91
Dirt roads 6 Arkin lots: 72' 82 S] 89
Impervious surfaces, pavement, roofs etc. X 98 98 98 98
O n water bodies:
lakes, wetlands, onde etc. II
p00
100
100
100
Single family raeidantial(2):
Owelling Unit/Gross Acre 9Impervious(3) Separate curve number
1.0 DU/GA 15 shall be selected for
1.5 DO/GA 20 pervi ous & tmpervioue
2.0 DU/GA 25 porti ons of the Bite
2.5 DU/GA 30 or be e in
3.0 DU/GA 34
3.5 DU/GA 38
4.0 DU/GA 42
4.5 DU/GA 46
5.D DU/GA 48
5.5 DU/GA 50
fi.0 DU/GA 52
6.5 DU/GA 54
7.0 DV/GA 56
PUD'e, condce, apartments, eimpervioue
comoercial businesse s a moat be
industrial ereae computed
(1) For a more detailed description of agricultural land use curve numbers refer
to National Engineering Handbook, sec. 4, Hydrology, Chapter 9, August 1972.
(2) Assumes roof and driveway runoff ie directed into street/storm system.
(3) The remaining pervious areas (lawn) are considered to be in goad
condition for these curve numbers.
III-1-12 FEBRUARY. 1992
APPENDIX C - THURSTON COUNTY FLOOD MAP
1l of ll
Thurston County Map Output Page
Page 1 of I
Thurston
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Diadalmae TFUrs[on County mvkes every effort ~o ensure [Fm [nis InaV Is a eme end
ara~e repre emmmaortne work orcoomv go. ear. Howe.<r, m<coalny aoa all
~„ LEGEND
plim,reyaremg me a~.om<y,
~emiw per ael hake oo warraan,<.paas<aor
mvln ms r r orany in[ormeuplntlaolosed oa nits mep-NOrdoea m<COamy /~/Diajor Roads ,` Food Zones
mep~ liability [many damage or Injury rvusvA Fy Ne i¢e oftnis mup.
To lno ful@s~ex¢m pmnkssible pnrsuam ~o applicable lmv, TM1ursron Cbun[y aisdvinss ell Roads
eKpas mVll<Q. mcuSm¢, Fu110~Gmi6a [q hnpCAu pp(ie6 ofinerchanl
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prieivry uignu'
avm fimcv'lnra pan rnlvrpwpps 'and norn Gnyun<ma aCp
abliry~ SLCed[LIS
L d 'wins ~I d 6~ Fu ~ I 1 I . ncbl' F II Thurs~on County be
ZORing
FI F ydire J "i 'denial ~p ^I - sem Id' ~E'iM1e~'<s Ftrom 12 ~
Contains
the use or, or one InaSJlry ~o use llrurnun County nmteno G_
tNetlands ,_t_ Cities
Iliul.eal 2 2001-'Ilmaion Coumy GenlJaia Cvnmr _.
l.~'~r{)i1~A 24114 Hed[agp COUr[SW, 3ra Floor We$dnd Bll(fEl'S PdCCB15
Cowrr Olympia, WA 98502-6031
http://geomap 1.geodata.org/servleUcom.esri.esrimap.Psrimap?ServiceName=cadastralov&_. 2/ 16/2007
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