Drainage and Erosion Report 001YELM COMMUNITY SCHOOLS
FORT STEVENS ELEMENTARY SCHOOL
YELM, WASHINTON
Drainage and Erosion Control Report
Proponent: Yelm Community School
P.O. Box 476
Yelm, WA 98597
(360)458-6128
Prepared By: Robert E. Tauscher, P.E.
Jerome W. Mortissette & Associates Inc., P.S.
1700 Cooper Point Road SW, #B2
Olympia, WA 98502
Phone. (360) 352-9456
Eax. (360)352-9990
Submitted: Mazch 2007
TABLE OF CONTENTS
I. DRAINAGE REPORT
Section 1 -Project Description 1
Section 2 -Existing Conditions 1
Section 3 -Infiltration Ra[e/Soils Report 1
Section 4 -Wells 2
Section 5 -Fuel Tanks 2
Section 6 -Sub-basin Description 2
Section 7 - 100 Yeaz Flood 2
Section 8 -Aesthetic Considerations 2
Section 9 -Facility Sizing and Downstream Analysis 2
Section 10 -Covenants, Dedications, and Easements 3
Section 11 -Articles of Incorporation 3
B. EROSION CONTROL REPORT
Section I -Sequence 4
Section 2 -Trapping Sediment 4
Section 3 -Permanent Erosion Control 4
Section 4 - Geotechnical Report 4
Section 5 -Inspection 4
Section 6 -Control of Pollutants Other than Sediment 5
III. APPENDIX
A. Soils Report and Flood Zone Map
B. Calculations
C. Commercial Stormwater Facilities Maintenance Agreement
D. Thurston Region Stonnwater Facilities Summary Form
E. Site Plan
Fort Stevens Elementary School
Drainage and Erosion Control Report
1WM&A # 06181
PROJECT ENGINEER'S CERTIFICATE
"I HEREBY CERTIFY THAT THIS PROJECT, FORT STEVENS ELEMENTARY
SCHOOL, YELM COMMUNITY SCHOOLS, YELM, WASHINGTON HAS BEEN
PREPARED BY ME OR UNDER MY SUPERVISION AND MEETS MINIMUM
STANDARDS OF CITY OF YELM AND NORMAL STANDARDS OF
ENGINEERING PRACTICE. I UNDERSTAND THAT THE JURISDICTION DOES
NOT AND WILL NOT ASSUME LIABILITY FOR THE SUFFICIENCY,
SUITABILITY, OR PERFORMANCE OF DRAINAGE FACILITIES DESIGNED BY
ME."
Y.~V`t^` / `KRAP~K~4---
Robert E. Tauscher, P.F.
Jerome W. Morrissette & Associates Inc., P.S.
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Fort Stevens Elementary School
Drainage and Erosion Conhrol Report
JWM&A # 06I8I
YELM COMMUNITY SCHOOLS
FORT STEVENS ELEMENTARY SCHOOL
YELM, WASHINGTON
DRAINAGE AND EROSION CONTROL REPORT
PART L DRAINAGE REPORT
This report has been prepared as part of the requirements for the Site Plan Review for the
subject site and in accordance with the "Stormwater Management Manual for the Puget
Sound Basin," 1992 and the CiTy of Yelm requirements.
Section i -Project Description:
The Fort Steven Elementary School site consists of 23.26 Acres located at 10347 Grove
Street SE. The site lies northeast of SR 507, west of the intersection of Grove Street and
Middle Road SE m Yelm, Washingtoq in the Southwest quarter (SW '/<) of the Southeast
quarter (SE %a) of Section twenty (20), Township seventeen (17) North, Range two (2)
East. 'i'he assessors parcel number is 64303600300.
The existing access will be from Middle Road SE.
The overall project will involve the construction of a 600 squaze foot restroom addition
onto the existing school build, a play shed and two portable classrooms. The stormwater
system from restroom addition will be connected to the existing downspout collection
system. The play shed and portable will be conveyed to a roof drywell system.
The stormwater system has been designed to the standards of the "Stormwater
Management Manual for the Puget Sound Basin," 1992.
Section 2 -Existing Conditions:
The site has a gentle down grade from NE to S W, with anapproximate I O-foot drop
across the parcel from elevation 342 in the northeast corner to 332 in the southwest
comer. The existing elementary school was built in 1989.
Section 3 - InfdtraNon Rates/Soils Report
Soils on the site aze listed in the Soi] Conservation Service's Soil Survey of Thurston
County Washington as Spanaway gravelly sandy loam and Spanaway stony sandy loam.
Typical soils are a dark grayish brown and gravelly sandy loam near the surface with dark
yellowish brown very gravelly sandy loam occurring within two feet of surface (See Soils
Report in Appendix A). The soil mapping from this soil survey indicates that the
predominant soil goup at this site is "B".
Fort Stevens Elamentary School ~
Drainage and Erosion Control Report
Section 4 -Wells and Septic Systems:
The school is currently connected to the City of Yelm Water System for supplying
potable water and an On-site Septic Disposal System is utilized for sanitary sewer. A
search of Department of Ecology web site was performed to identify any additional wells.
The search yielded no additional wells within 200 feet of the property.
Section 5 -Fuel Tanks:
Based on information from the current property owner, numerous site inspections, and the
expressed intentions of the owner, it is evident that there are no known fuel tanks existing
on the property. No fuel tanks will be brought onto the properly during development.
Section 6 -Sub-basin Description:
The restroom addition roof runoff will be connected to the existing roof downspout
piping system. The play shed and the two new portable classrooms runoff will be routed
to a roof drywell for disposal.
Section 7 - 100 Year Flood:
The project does not contain a stream but is near Yelm creek. The southwest port of the
site is within the flood zone, as mapped by the Thurston County Geodata (copy of the
Flood Zone as mapped on [he Thurston County Geodata site can be found in Appendix
B). The proposed improvements aze all outside the flood zone.
Section 8 -Aesthetic Considerafions:
All disturbed areas will be vegetated or landscaped. The stormwater facilities consist of a
conveyance piping and an underground drywell.
Consequently, the overall aesthetic affect of the stormwater facilities on this site will be
consistent with other facilities within the vicinity and should not detract from surrounding
areas.
Secfion 9 -Facility Sizing and Downstream Analysis:
The impacts of the proposed development on stormwater runoff have been analyzed in
accordance with the procedure described in the "Stormwa[er Management Manual for the
Puget Sound Basin," 1992. All stormwater conveyance and roof drywell systems were
designed for the 100 Year /24 Hour Design F,vent as outlined in the above listed Manual.
The hydraulic analysis for the on-site stormwater facilities can be found in Appendix B.
Fort Stevens Elementary School
Drainage and Erasion Control Report
IWM&A N 06!81
POST DEVELOPMENT SITE CHARACTERISTICS
Total Site Area 26.26 Acres
Rest Room Roof Areas (Acres): 0.01 Acres
Play Shed and Portable Classroom Atea (Acres): 0.16 Acres
SCS Data Hydrologic Soil Group "B"
SYSTEM MINIMUM REQUIREMENTS
Areas
Total Area Tributary to Drywell (Acres): 0.16 Acres
Required Volume per Manual 849 CF
Volume Provided 864 CF
Downstream Analysis
There are no downstream impacts due to all stormwater being detained and infiltrated on
site.
Section 10 -Covenants, Dedications, Easements:
Operation and maintenance of the stormwater drywell and piping will be the
responsibility of the property owner. 'the facilities will require routine maintenance and a
draft Commereial/Industrial Stonnwater Facilities Maintenance Agreement prepazed for
this project is located in Appendix D.
Section 11 -Articles of Incorporation:
The parcel is privately owned, Articles of Incorporation are not required for the proposal.
Fort Sevens Elementary School 3
Drainage and Erosion Control Report
JWM&A # 06181
PART 11. EROSION CONTROL REPORT
Secfion 1 -Sequence:
The following is the construction sequence for constmetion of the parking lots and
galleries.
1. Install stormwater collection system and drywell.
2. Finish grade, topsoil, fertilize, and seed disturbed areas.
Section 2 -Trapping Sediment:
The site is 23.26 acres, and the proposed improvements aze located in the general center
of the pazcel. No erosion is anticipated during construction, the drywell is m the back of
the school, with the surrounding area is covered with grass.
The entrance is paved and paved city streets surzound the site. If a substantial amount of
soil is being deposited on adjacent streets due to truck traffic, the road will immediately
be cleaned of all debris and further preventative measures will be taken [o ensure the
problem ceases, such as establishing a tire wash down area.
All of the above features of the Erosion and Sedimentation Control Plan, if installed and
periodically maintained, aze expected to minimize the potential for sediment-laden nmoff
escaping the site and entering the downstream environment during and after the
construction of the project.
Section 3 -Permanent Erosion Control:
The following measures will be taken for soil stabilization to minimize the amount of
sediment-laden runoff entering adjacent properties.
• Stabilization of disturbed areas with hydro seeding and, if necessary, chopped hay
mulching (or jute matting).
Permanent erosion control on this site will be accomplished through the development of
grass groundcover on all disturbed areas.
Section 4 - Geotechnical Report:
There are no other incipiently unstable stormwa[er related conditions within the project
site, hence; no other additional soil investigations or analyses aze planned.
Section 5 -Inspection:
Fort Stevens Elementary School
Damage and Erosion Control Report
1WM&A N 06181
The Owner will monitor the construction of stormwater facilities on the subject site and
the Owner's representative in accordance with the requirements of the Drainage Manual.
The following is the recommended inspection sequence for the construction of
stormwater facilities described above:
At completion of the drywell, fine grading and seeding.
Section 6 - Control of Pollutants Other Than Sediments:
As the subject site is currently used as a school site, it will most likely not involve the
storage or use of non-sediment pollutants on this site. Temporary pollutant sources and
construction waste materials may develop for short periods during the construction of the
stormwater facilities. Care will be taken to minimize the adverse impacts of these
conditions. Bulk petrochemical storage, in the form of gasoline, fuel, oil, lubricants, and
other such hazardous fluids will not be permitted on this site.
Fort Stevens Elementary School 5
Drainage and Erosion Control Repott
J WM&A H 06181
APPENDIX A
SOILS REPORT
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CALCULATIONS
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APPENDIX C
COMMERCIAL STORMWATER
FACILITIES MAINTENANCE
AGREEMENT
COMMERCIAL/INDUSTRIAL
AGREEMENT TO MAINTAIN
STORMWATER FACILITIES AND TO IMPLEMENT A
POLLUTION SOURCE CONTROL PLAN
BY AND BETWEEN
YELM COMMUNITY SCHOOLS
ITS HEIRS, SUCCESSORS, OR ASSIGNS
(HEREINAFTER "OWNER")
AND CITY OF YELM
(HEREINAFTER "JURISDICTION°)
The upkeep and maintenance of stonnwater facilities and the implementation of pollution
source control best management practices (BMPs) is essential to the protection of water
resources. All property owners aze expected to conduct business in a manner that
promotes environmental protection. This Agreement contains speci5c provisions with
respect to maintenance of stormwater facilities and use of pollution source control BMPs.
LEGAL DESCRIPTION:
Parcel numbers 64303600300, in the City of Yelm
Whereas, O WNER has constructed improvements, including but not limited to, buildings,
pavement, utilities and stormwater facilities on the property described above. In order to
further the goals of the JURISDICTION and [o ensure the protection and enhancement of
water resources, the JURISDICTION and OWNER hereby enter into this Agreement.
The responsibilities of each party to this Agreement are identified below.
OWNER SHALL:
(1) Implement the stormwater facility maintenance program included herein as
Attachment "A".
(2) Implement the pollution source control program included herein as Attachment
..B,.
(3) Maintain a record (in the form of a logbook) of steps taken [o implement the
programs referenced in (1) and (2) above. The logbook shall be available for
inspection by Jurisdiction staff at 10336 West Rd SE during normal business
hours. The logbook shall catalog the action taken, who took it, when it was done,
how it was done, and any problems encountered or follow-on actions
recommended. Maintenance items ("problems") listed in Attachment "A" shall be
inspected on a monthly or more frequent basis as necessary. OWNER is
encouraged to photocopy the individual checklists in Attachment "A" and use
them to complete its inspections. These completed checklists would then, in
combination, comprise the monthly logbook.
(4) Submit an annual report to the JURISDICTION regazding implementation of the
programs referenced in (1) and (2) above. 'The report must be submitted on or
before May I S of each calendar year and shall contain, at a minimum, the
following:
(a) Name, address and telephone number of the businesses, the persons, or the
firths responsible for plan implementation, and the person completing the
report.
(b) Time period covered by the report.
(c) A chronological summary of activities conducted to implement the
programs referenced in (1) and (2) above. A photocopy of the applicable
sections of the logbook, with any additional explanation needed, shall
normally suffice. For any activities conducted by paid parties not
affiliated with OWNER, include a copy of the invoice for services.
(d) An outline of planned activities for the next year.
THE .iIJRISDICTION SHALL:
(1) Provide technical assistance to OWNER in support of its operation and
maintenance activities conducted pursuant to its maintenance and source control
programs. Said assistance shall be provided upon request, and as Jurisdiction
time and resources permit, at no charge to OWNER.
(2) Review the annual report and conduct a minimum of one (I) site visit per yeaz to
discuss performance and problems with OWNER.
(3) Review this agreement with OWNER and modify it as necessary at least once
every three (3) years.
REMEDIES:
(I) If the JURISDICTION determines that maintenance or repair work is required to
be done to the stormwa[er facilities existing on OWNER, property, the
JURISDICTION shall give the owner of the property within which the drainage
facility is located, and the person or agent in control of said property, notice of the
specific maintenance and/or repair required. The JURISDICTION shall set a
reasonable 4ime in which such work is to be completed by the persons who were
given notice. If the above required maintenance and/or repay is not completed
within the time set by the JURISDICTION, written notice will be sent to the
persons who were given notice stating the JURISDICTION' S intention to perform
such maintenance and bill the owner for all incurred expenses. 172e Jurisdiction
may also revoke stormwater utility rate credits for the quality component or
invoke surcharges to the quantity component of OWNER bill if required
maintenance is not performed.
(2) If at any time the JURISDICTION detemtines that the existing system creates any
imminent threat to public health or welfare, the JURISDICTION may take
immediate measures to remedy said threat. No notice to the persons listed in
Remedies (1), above, shall be required under such circumstances.
(3) The owner grants unrestricted authority to the JURISDICTION for access to any
and all stormwater system features for the purpose of performing maintenance or
repair as may become necessary under Remedies 1 and/or 2.
(4) The persons listed in (I ), above, shall assume all responsibility for the cost of any
maintenance and for repairs to the stormwater facility. Such responsibility shall
include reimbursement to the JURISDICTION within 30 days of the receipt of the
invoice for any such work performed. Overdue payments will require payment of
interest at the current legal rate for liquidatedjudgmen[s. If legal action ensues,
any cost or fees incurred by the JURISDICTION will be borne by the parties
responsible for said reimbursements.
(5) The owner hereby grants to the JURISDICTION a lien against the above-
described property in an amount equal to the cost incurred by the JURISDICTION
to perform the maintenance or repair work described herein.
This Ageement is intended [o protect the value and desirability of the real properly described
above and [o benefit all the citizens of the Jurisdiction. It shall run with the land and be binding
on all parties having or acquiring from OWNER or their successors any rights, title, or interest in
the properly or any part thereof, as well as their title, or interest in tha property or any part
thereof, as well as their heirs, successors, and assigns. They shall inure [o the benefit of each
present or future successor in interest of said property or any part thereof, or interest thereiq and
[o the benefit of all citizens ofthe JURISDICTION.
STATE OF WASHINGTON )
SS
COUNTY OF TJIIJRSTON )
Owner
Owner
On this day and year personally appeared before me, and
known to be the individual(s) described, and who executed
the foregoing instrument and acknowledge the said instrument to be the free and voluntary act
and deed for [he uses and purposes [herein mentioned.
Given under my hand and official seal this day of , 200
Notary Public in and for the Stale of
Washingoq residing in
Dated at Washingtoq this day of , 200
STATE OF WASHINGTON )
)SS
COUNTY OF TA[JRSTON )
On this day and year personally appeared before me,
who executed the foregoing instrument and acknowledge the
said instrument to be the free and voluntary ac[ and deed of said Municipal Corpom[ion for the
uses and purposes [herein mentioned and on oath sm[es he is authorized to execute the said
instrument.
Given under my hand and official seal this day of , 200
Notary Public in and for [he Stale of
Washing[oq residing in
APPROVED AS TO
INSTRUCTIONS FOR PERSON MAINTAINING
STORMWATER SYSTEM
The following pages describe the maintenance needs of the stormwater conveyance,
storage and disposal components of the system designed for [his site. This maintenance
effort shall be the responsibility of the Yelm Community Schoolsr its assigned
representative. Tn general, system components should be inspected in accordance with
the Maintenance Checklists included as Attachment "A" at the rear of this document.
Use the suggested frequency indicated on the left side of the Checklist Fomrs:
Q) Monody (M) from November though April
(2) Annually (A), once in late summer (preferably September)
(3) After major storm events (S)>1 inch in 24 hours.
Inspection 5ndings should be recorded on photocopies of Maintenance Checklist forms.
Check off the problems you looked for each time an inspection was performed.
Maintenance should be undertaken to correct deficiencies found and comments on
problems found and actions taken entered on the forms.
Completed Checklist Forms should be filed and incorporated in the annual report to be
issued in May of each yeaz.
If you have specific questions or require technical assistance, contact the responsible
jurisdiction. Please do not hesitate to call, especially if you aze unsure whether a situation
you have discovered may be a problem.
ATTACHMENT "A°: MAINTENANCE PROGRAM
COVER SHEET
Inspection Period:
Number of Sheets Attached:
Date Inspected:
Name of Inspector:
Inspector's Signature:
ATTACHMENT"B"
POLLUTION SOURCE CONTROL PROGRAM
Pollution source controls are actions taken be a person or business to reduce the amount
of pollution reaching surface water and groundwater. A conscious control program is of
significant importance to the YELM COMMUNITY SCHOOLS, as runoff will be
directed to a constmeted wetland and infiltration disposal facility that will ultimately
introduce the wllected runoff in to the shallow groundwater system. Many pollutants
generated on commercial sites cannot be removed from the runoff by conventional
treatment and may eventually enter the shallow groundwater system. Hence, it is of great
importance to limit [he development of these pollutants in the generated stormwater
mnoff.
The subject controls aze also known as "Best Management Practices" (BMP's), include:
• Minimizing vegetation/groundcover disturbance.
• Stabilizing existing exposed soil surfaces through fertilizing and seeding, and
mulching with chopped hay during the wet season Q S October through 15
March).
• Maintaining roof, sidewalk and paved driveway areas free of debris accumulation;
refraining from using soaps and detergents in washing these exterior surfaces; and
carefully controlling activities in these areas so as to preclude hazardous materials
spills (i.e. chemical storage, vehicle maintenance, etc.).
• Substitute non-toxic products for toxic materials; recycle used oil and antifreeze
immediately.
• Refrain from storing hazardous or toxic chemicals or other substances. Where it
is imperative to store such materials, enclose them in a lockable cabinet.
• Limit the use of fertilizers and pesticides to the precise amount recommended by
professionals working the area.
Pollution source controls are needed because of the contamination found in runoff from
commercial areas and the effect of this contamination on aquatic life and human health.
Research on urban runoff in the Puget Sound area and elsewhere has found oil and grease,
nutrients, organic substances, toxic metals, bacteria, viruses, and sediments at
unacceptable levels. Effects of contaminated runoff include closure of shellfish
harvesting aeeas and swimming areas, mortality of young fish and other aquatic
organisms, tumors on fish and impairment of fish reproduction.
Drywalls, French Drains, or Downspouts
Part of
System to
Check When to
Check it What to Check For What to Do
Downspout Annualty Water overflows from the Downspout over the Fireltry cleaning out the
ground. ggutters antl tlownspouts.
If this doesn't salve the
problem you mayY need to
install a bgger tlrywell.
Roof Annually Moss antl algae are faking over the shadier Diswnned the flexible
parts of the shingles. art of the Downspout that
Peads to the tlrywell.
Pertonn moss removal as
tlesiretl. Pressure wash
or use fa acitl solutions
instead of Shy toxic
pesticitles or chlorine
bleach. Install a zinc strip
as a preventative.
Grounds and Landscaping
Part of When to What to Check For What to Do
Grounds [o Check if
Check
Lantlsppetl Quarterly Weetls growing out of control in landscaped Pull weetls by hand, if
Areas area. possible, to avoitl using
chemical weetl cpntrols.
Lantlscepetl Quartery Check for any presence of poison ivy or other Remove poisonous
Areas poisonous vegetation or insect nests. vegetation ar insect nests that
are present in lantlswpetl
area.
Lantlscapetl Quarterly There shoultl not be any yartl waste or Idter in Remove and dispose of litter
Areas landscaped areas. properly
Landscaped
A puarterly Noticeable ells are seen in lantlsrapetl areas. Itlentify the causes of erosion
reas and takke steps to slow down
or dis
erse the wat
r Fill in
p
e
wmour, and seed area.
Trees antl Annually Limbs or parts of trees or shrubs that are split Trim trees antl shrubs to
shrubs or broken. restore shape. Replace
severely damagetl trees antl
shmbs.
Trees end Annually Trees or shrubs that have been blown town or Replant trees or shrubs,
shrubs knocketl over. inspecting for injury to stem or
roots. Replace if severely
tlamagetl.
Trees antl Annually Trees or shrubs that are not atlequately Place stakes and rubber-
Shrubs supported or are leaning over, causing ccatetl ties arountl young
exposure of the roots. trees/shrubs tar support.
Conveyance Pipea, Ditches, and Swales
Part of When to What to Check For What to Do
Sysfem to Check it
Check
Pipes Annually Accumulatetl sediment should not exceed 20% Clean out pipes of all
of the diameter of the pipe. Vegetation should sediment antl tlebns.
net reduce free movement of water through Remove all vegetation so
pipes Ensure that the yrotedive ceeting is not that water flows freely
damagetl and rusted Dents shoultl not through pipes. Repan or
significantly impede flow. PipPee should not replace pipe.
have major crecks or tears ailewing water to
leak out.
Open ditches Quarterly There shoultl not be any yaN waste or liner in Remove trash antl tlebds
the tlitch. antl tlisposa of them
propedY.
Open tlkches Annually Accumulatetl sediment shoultl not exceed 2g% Clean out tlkch of all
of the tlepth of the tlkch. sediment antl tlebds.
Open tlitches 8 Annually Check br vegetation (e g., weedy shrubs or Clear blocking vegetation so
Swales sapiings)that retluces the free movement of that water flows freely
water through tlkches or swaks. through tlkches. Grassy
vegetation shoultl be left
alone.
Open dtches 8 Ouartedy Check arountl inleLS antl outlets fot signs of Eliminate causes of erasion.
Swales erosion. Check slopes for signs of slougghing
ali
A
ti
i
tl
d
h Stabilize slopes by using
i
or se
ng.
c
on
s nae
e
w
ere erotletl appropr
ate erosion control
tlamage is over 2 inches deep aM where there measures (e.g., reinforce
is potential for continuetl erosion. wiM rock, plant grass,
vim act soil.
Open dachas 8 Annually Native soil beneath the rock splash paQ check Replace rocks to design
Swales dam, or lining shoultl not be visible. stentlard.
Swales Quarterly Grass cover is sparse antl vreetly, or areas are Aerate sails and reseed and
overgrown with wootly vegetation mulch bare areas. Keep
grass less then 8 inches
high Remove wootly
growth, regrotle, and reseetl
as necessary.
Swales Quarterly Swale has been filletl in or blocked by sheQ If possible, speak wkh
wootlpile, shrubbery, etc. homeowner antl request that
the ewale area be restoretl.
Swales Annually Waterstantls in swale or now velocity is very Asurvey may be neetled to
slow. Stagnation occurs. check grades. Gretles neetl
to be in 1-5% range a
possible. If pratle is less
than 1% underdmins may
n
d t
h
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ll
d
ee
o
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ns
a
e
.
APPENDIX D
THURSTON REGION
STORMWATER FACILITIES SUMMARY
THURSTON REGION
FAC[LTTY SUMMARY FORM
PROPONENT'S FACILITY IDENTIFIER: Yelm Community Schools
NAMF, OF ROAD TO ACCESS FACILITY: Middle Road SE
HEARINGS EXAMINER CASE NUMBER:
DEVELOPMENT REVIEW PROJECT NO.:
BUILDING SITE APPLICATION NO.:
PARCEL NUMBER(S) 64303600300
To be completed by Utility Staff:
Utility Facility Number:
Project Number:
Parcel Number Status:
Basin & Subbasin:
Responsible Jurisdiction:
PART 1 -Project Name & Proponent
Project Name: Fort Stevens Elementary School
Project Owner: Yelm Community Schools
Project Contact: Erling Birkland
Address: P.O. Sox 476, Yelm, WA 98597
'Telephone: (360) 458-6128
Project Proponent: Yelm Community Schools
Address: P.O. Box 476, Yelm, WA 98597
Telephone: (360) 458-6128
Project Engineer: Robert E. Tauscher, P.E.
Firm: J.W. Morrissette & Associates Inc., P.S.
Telephone: (360) 352-9456
Fax: (360) 352-9990
PART 2 -Project Location
Section: 20
Township: 17N
Range: 2E
PART 3 - Type of Permit Application
Type of Permit: Site Plan Review
Other Permits:
Grading
Other:
Other Agencies that have had or will review this Drainage & Erosion Control Plan:
None
PART 4 -Proposed Project Description
What stream basin is this project within: Nisqually River
Zoning: ID, R-6
Onsite: ] 0347 Grove Rd SE
Number of Lots: 1
Lot Size: 23.26 Acres
Building Permit:
New Building Footprint (Acres): 0.17
Existing Impervious (Acres):
Existing Pervious (Acres):
Disturbed Area Total (Acres):
Total Area (Acres):
PART 5 -Pre-Developed Project Site Characteristics
Stream Through Site N
Steep Slopes (> 10%) N
Erosion Hazard N
100-Yeaz Flood Plain y
Wetlands N
Seeps/Springs N
High Groundwater Table N
Aquifer Sensitive Area N
Other:
6.97
16.29
0.17
23.26
PART 6 -Facility Description
Total Site Area 26.26 Acres
Rest Room Roof Areas 0.01 Acres
Play Shed and Portable Classroom Areas 0.16 Acres
En[er a check mazk and number, i.e., one (1), for the type of facility:
Wet Gallery Detention 0
Wet gallery water surface azea, acres 0
Dry Gallery Detention 0
Underground Detention: 0
Infiltration Trench: 0
Dry Well Infiltration: 1
Other 0
Outlet Type (Enter a check mazk and number, i.e., one (1), for each type present):
Filter. 0
Oil/Water Sepazator: 0
Single Orifice:
Multiple Orifices:
Weir:
Spillway:
Pump(s):
Other:
PART 7- Zoae 1 -Release to Groundwater
Design Percolation Rate to Groundwater 10 in/hr
PART S- Zoae 1 -Release To Surface Water
Al] stormwater from this site is infiltrated on site with no release to any surface waters.
APPENDIX E
SITE PLAN