Prelim Drainage Report^The Shea Group
a Parametrix compar7y
Yelm Alternative School
Preliminary Drainage Report
August, 2001
Engineering • Planning • Environmental Sciences
Preliminary Drainage Report
Yelm Alternative School
Former Jayhawk's Building
Yelm, WA
August 2001
Project Information
Project: Yelm Alternative School
Prepared for: Yelm Community Schools
Contact: Erling Birkland
P.O. Box 476
Yelm, WA 98597
Reviewing Agency
Jurisdiction:
Project Number:
Project Contact Gary Hooper
City of Yelm
Project Engineer
Prepared by: The Shea Group
8830 Tallon Lane
PO Box 3427
Lacey, WA 98516
(360) 459-3609 FAX (360) 459-0154
Contact: Thomas A. Trotter, P.E., Project Engineer
Job #: 242-4175-QOl
File Number: k:\4175-Yelm Community Schools \Contract \Yelm Alternative School
\Phase O1 SUP Support \Deliverables \Reports \4175001pdr.rtf
PROJECT ENGINEERS CERTIFICATION: I hereby certify that this Preliminary
Drainage Report for the Yelm Alternative School in Yelm, Washington has been
prepared by me or under my supervision and meets the intent of the Thurston County
Drainage Design and Erosion Controi Manual (DDECM), unless noted otherwise, and
normal standards of engineering practice. I understand that the jurisdiction foes not and
will not assume liability for the sufficiency, suitability, or performance of drainage
facilities designed for this development.
EXPIRES 05~iQo3
Table of Contents
PART I STORM DRAINAGE REPORT
SECTION 1 -PROPOSED PROJECT DESCRIPTION ............................... 2
SECTION 2 -EXISTING CONDITIONS .................................................... . 5
SECTION 3 -INFILTRATION RATES/SOILS REPORT ........................... . 5
SECTION 4 -WELLS AND SEPTIC SYSTEMS ........................................ . 6
SECTION 5 -FUEL TANKS ........................................................................ . 6
SECTION 6 -SUB-BASIN DESCRIPTION ................................................ . 6
SECTION 7 -ANALYSIS OF 100 YEAR FLOOD ..................................... . 6
SECTION 8 -AESTHETIC CONSIDERATIONS ...................................... . 6
SECTION 9 -DOWNSTREAM ANALYSIS AND FACILITY SIZING .... . 6
SECTION 10 -COVENANTS, DEDICATIONS, EASEMENTS ................ . 7
SECTION 11 -ARTICLES OF INCORPORATION .................................... . 7
PART II EROSION CONTROL REPORT
SECTION 1 -CONSTRUCTION SEQUENCE AND PROCEDURE.......... . 7
SECTION 2 -TRAPPING SEDINIENT ....................................................... . 8
SECTION 3 -EROSION CONTROL & SITE RESTORATION ................. 8
SECTION 4 -GEOTECHNICAL ANALYSIS AND REPORT .................... 9
SECTION 5 -INSPECTION SEQUENCE .................................................. .. 9
SECTION 6-CONTROL OF POLLUTANTS ............................................... 9
PART III MAINTENANCE PLAN
SECTION 1 -REQUIRED MAINTENANCE ............................................. 10
SECTION 2 -RESPONSIBLE ORGANIZATION ...................................... 20
SECTION 3 -VEGETATION MANAGEMENT PLAN ............................. 20
SECTION 4 -SOURCE CONTROL ............................................................ 20
APPENDICES
Appendix I-Pre]iminary Drainage Calculations
Appendix II -Vicinity Map
Appendix III -Drainage Plan
Appendix N -Facility Summary Form
Appendix V - SCS Soils Map
Appendix VI - FEMA Firm Map
Appendix VII -Commercial Maintenance Agreement
Yelm Alternative School, Preliminary Drainage Report
PART I STORM DRAINAGE REPORT
The format of this report follows the outline provided in the Thurston County Drainage Design and
Erosion Control Manual (DDECM), 1991 and 1994 Editions.
SECTION 1 -PROPOSED PROJECT DESCRIPTION
Project Proponent: Yelm Community Schools
P.O. Box 476
Yelm, WA 98597
Parcel Numbers: 64421800100, 64421701000, 64400100100, 64400600100,
64400600300,64421700900,64421700800,64421700600
Total Site Area: 1.94 acres
Zoned: Central Business District
Site Address: 107 SE 1st Street, Yelm, Washington
Required Permits: Grading, Utility, Plumbing, Electrical,
Section, Township, Range: Section 49, Township 17N, Range 2 East, W.M.
Thurston County, Washington
The site is located in the City of Yelm and is bordered on the west by commercial properties; on the north
by Burlington Northern Railroad; on the south and east by single family homes.
The proposal is to convert the former Jayhawks building and site into a Yelm Alternative School. This
redevelopment consists of providing full road frontage improvements along Jefferson Avenue and half
road frontage improvements along 2°d Street (south of Jefferson Avenue). The existing parking lot will be
reconfigured with new striping, landscaping islands, and lighting. The site is already serviced by City of
Yelm water on 15~ Street and City of Yelm STEP sewer on Jefferson Street. The adequacy of these
existing water and sewer services will be verified during the design phase.
This site has history of minor, localized flooding problems, and the existing storm drainage control
structures and underground facilities are inadequate. The entire site will be brought up to current
standards in accordance with the Department of Ecology Stormwater Manual (1992 DOE) and City of
Yelm requirements.
The Shea Group Page 2
August 2001
Yelm Alternative School, Preliminary Drainage Report
Storm Drainage Improvements:
Once completed, the Yelm Alternative School will include approximately 0.83 acres of impervious road,
driveway, and alley areas, 0.04 acres of sidewalk areas, 0.60 acres of disturbed pervious area, and 0.47
acres of roof area on-site. The off-site frontage improvements that are tributary to this project site include
0.52 acres of impervious road, 0.12 acres of sidewalk areas, and 0.12 acres of landscaping. The on-site
and off-site areas were combined into two basin areas for storm drainage design purposes (Basin 1 &
Basin 2).
Total On-Site Development Coverage Summary
Existing_(ac) Proposed (ac)
Impervious Roof 0.47 0.47
Impervious Alleys & Parking 0.70 0.78
Impervious Sidewalk 0.07 0.04
Gravel Parking 0.1 S 0.06
Disturbed Pervious 0.00 0.60
Undisturbed Pervious 0.55 0.00
Total 1.94 1.94
Total Off-Site Development Coverage Summary
Existing (ac) Proposed (ac)
Impervious Road 0.54 0.52
Impervious Sidewalk 0.05 0.12
Gravel Road 0.03 0.00
Disturbed Pervious 0.00 0.12
Undisturbed Pervious 0.14 0.00
Total 0.76 0.76
Pre-Development Basin Summary
Basin 1 (Ac) Basin 2 (Ac) Total Ac
Impervious 1.54 0.47 2.01
Disturbed Pervious 0.00 0.00 0.00
Undisturbed Pervious 0.69 0.00 0.69
Total 2.23 0.47 2.70
Post-Development Basin Summary
Basin 1 (Ac) Basin 2 (Ac) Total Ac
Impervious 1.51 0.47 1.98
Disturbed Pervious 0.72 0.00 0.72
Undisturbed Pervious 0.00 0.00 0.00
Total 2.23 0.47 2.70
The Shea Group Page 3
August 2001
Yelm Alternative School, Preliminary Drainage Report
Stormwater Treatment:
Basin 1:
This basin includes all on-site area, except for the roof area, in addition to a portion of Jefferson
Street and a portion of Second Avenue (Refer to Appendix III for the storm drainage and erosion
control plan). New roadways, parking lots, sidewalks, and driveways will generate runoff, which
will sheet flow to new catch basins. Stormwater runoff will be conveyed to a wetpond located
north of Jefferson Street. Roof runoff will be tightlined from the existing buildings to the proposed
underground storm conveyance system. Basin 1 was modeled using StormSHED design software.
The volume of stormwater runoff from the 6-month, 24-hour storm event is equal to 9,667 cubic
feet. The 1992 DOE requires the wetpond volume be large enough to store the runoff volume from
this 6-month storm event. The proposed wetpond has two cells. Cell #1 is 3 feet deep and has a
volume of 6,485 cubic feet. Cell #2 is 4 feet deep and has a volume of 5,667 cubic feet. This
yields a total pond volume of 12,152 cubic feet, which exceeds the minimum volume of 9,667
cubic feet (See preliminary treatment calculations in Appendix I).
Basin 2:
This basin consists of roof area only. The stormwater runoff from the existing roof will be
tightlined directly into two roof drywells. This runoff is from "clean" impervious surfaces and
does not require treatment. Basin 2 is 0.47 acres in size.
Treatment Area Summar
Basin # Impervious Area Disturbed Pervious
Area Treatment
Required Treatment
Provided
Basin 1 1.51 ac. 0.72 ac. 9,667 c.f. 12,152 c.f.
Basin 2 0.47 ac. 0.00 ac. None None
Stormwater Storage:
Preliminary storage requirements were based on the Soil Survey of Thurston County (refer to
Appendix V). Soil and infiltration testing will be performed for the final calculations. Assuming a
site infiltration rate of at least 40 inches/hour and a factor of safety of at least 2, a design infiltration
rate of 20 inches/hour was used for this preliminary design (Refer to Appendix I for preliminary
storage calculations).
Basin l:
Treated runoff from the wetpond in Basin 1 will overflow into an infiltration pond for storage and
infiltration. StormSHED was used to model this basin for both the 10-year, 24-hour and the 100-
year, 24-hour storm events. Darcy's Law was used to set up aotage-discharge relationship for this
pond. StormSHED resulted in a minimum required storage volume of 3,985 cubic feet for the 100-
year storm event. The infiltration pond has a volume of 7,750 cubic feet, which exceeds the
minimum volume of 3,985 cubic feet. The 1992 DOE also requires that the infiltration pond be
The Shea Group Page 4
August 2001
Yelm Alternative School, Preliminary Drainage Report
sized so that the 10-year storm event can be completely drained within 24 hours and the 100-year
storm event is completely drained within 72 hours. The 10-year storm event will have a design
water depth of 0.93 feet and will completely drain in 0.6 hours. The 100-year storm event will
have a design water depth of 1.19 feet and will completely drain in 0.7 hours.
Basin 2:
Roof drywells were sized in accordance with Chapter 8, Table 8.2 in the Drainage Design and
Erosion Control Manual (DDECM) for Thurston County. The minimum required drywell volume
is 2,559 cubic feet for a roof area of 0.47 acres and SCS Group B soils. Two drywells will be
provided north of the existing building (off-site). The City of Yelm has granted permission to
locate the drywells on the adjacent property which is city owned. Each drywell will be 100 feet
long, 3.5 feet wide, and 4 feet deep. The total volume provided is 2,800 cubic feet which exceeds
the minimum volume of 2,559 cubic feet.
Storage Ca acity Summary
Basin # Impervious Area Disturbed Pervious
Area Storage Volume
Required Storage Volume
Provided
Basin 1 1.51 ac. 0.72 ac. 3,985 c.f. 7,750 c.f.
Basin 2 0.47 ac. 0.00 ac. 2,559 c.f. 2,800 c.f.
SECTION 2 -EXISTING CONDITIONS
Five of the eight parcels, which have already been developed, are mostly covered with impervious
surfaces such as roof, sidewalks, and parking lots. The remaining three parcels are undeveloped and
consists of grass and several deciduous trees. This site is located in an aquifer sensitive area. The site
slopes are relatively flat and gentle with undulating ground. A topographic survey indicates there is
approximately 15 ft of vertical relief from the west corner of the building to the east corner of the
property line along 2nd Street.
There are no drainage channels within or near the site and no off-site drainage enters the site. The
existing storm drainage system collects and infiltrates runoff on-site. There are no creeks, lakes, ponds,
wetlands, ravines, gullies, steep slopes, springs, or any other environmentally sensitive areas on-site or
down gradient of the property.
SECTION 3 -INFILTRATION RATES/SOILS REPORT
The Soil Conservation Service (SCS) Soil Survey of Thurston County maps the on-site soils as an
Spanaway stony sandy loam (0-3% slopes) and Spanaway gravelly sandy loam (0-3% slopes). This soil
type features Hydrologic Group B characteristics. Refer to Appendix V for the SCS Soils Map.
No on-site soil tests have been completed for this preliminary drainage report. Soil tests will be
performed the final drainage report
The Shea Group Page 5
August 2001
Yelm Alternative School, Preliminary Drainage Report
SECTION 4 -WELLS AND SEPTIC SYSTEMS
The existing site and adjacent property owners are on the City of Yelm water system. No on-site wells
were found during our site investigation of the proposed development area.
The existing site is serviced by the City of Yelm STEP sewer system. There is a 3,000-gallon sewer
STEP tank behind the building. This STEP tank will be used by the Yelm Alternative School if it is
determined to be adequate during the design phase. No abandoned septic systems were identified during
our site investigation. Any septic system found shall be removed in accordance with Thurston County
Department of Health Standards.
SECTION 5 -FUEL TANKS
No fuel tanks were located during the site investigation. Based on information provided by the project
developer, no buried fuel tanks are known to exist. Additionally, a review of the DOE's Leaking
Underground Storage Tanks (LUST) list did not indicate any existing or abandoned fuel tanks on the
project site.
SECTION 6 -SUB-BASIN DESCRIPTION
Although the project is located in the Yelm Creek Basin, there will be no runoff from the project site for
the 100-year, 24-hour storm event. There is no significant off-site runoff to the project site.
Handling of hazardous materials is not anticipated on the project site.
SECTION 7 -ANALYSIS OF 100 YEAR FLOOD
The project site does not lay adjacent to or contain a major stream on-site, therefore it has not been
identified as a flood hazard area. The FEMA Firm Map for the City of Yelm classifies the site as Zone X,
which is outside the 500-year flood plain. Refer to the FEMA Firm Map in Appendix VI.
SECTION S -AESTHETIC CONSIDERATIONS FOR STORMWATER FACILITIES
All disturbed areas will be vegetated and landscaped. The stormwater ponds have been designed to allow
both aesthetic and functional characteristics. Aesthetics of facilities will be in keeping with similar
facilities in the vicinity.
SECTION 9 -DOWNSTREAM ANALYSIS AND FACILITY SIZING
There will be no runoff from the project site for the 100-year, 24-hour storm event, therefore, no
downstream analysis is necessary.
Please refer to Appendix I for all storm drainage calculations.
The Shea Group Page 6
August 2001
Yelm Alternative School, Preliminary Drainage Report
SECTION 10 -COVENANTS, DEDICATIONS, EASEMENTS
The on-site storm drainage facilities, including treatment and detention ponds, catch basins, and pipes will
require routine maintenance. A draft maintenance agreement between the owner and the City of Yelm is
included in Appendix VII that will allow the City access to facilities. The owner is responsible for
performing regular maintenance of the storm drainage facilities. The City of Yelm will provide technical
assistance at the owner's request.
SECTION 11 -PROPERTY OWNERS ASSOCIATION ARTICLES OF INCORPORATION
Maintenance of the private storm drainage facilities will be performed by the owner and/or their
representative; therefore, no property owners association is required.
The Shea Group Page 7
August 2001
Yelm Alternative School, Preliminary Drainage Report
PART II EROSION CONTROL REPORT
SECTION 1 -CONSTRUCTION SEQUENCE AND PROCEDURE
The proposed development of Yelm Alternative School includes an erosion control plan designed to
contain silt and soil within the project boundaries during construction, and permanent erosion control
afterward. Erosion/sedimentation control is achieved by a combination of structuraUvegetation cover
measures and construction practices tailored to fit the site.
Best Construction Management Practices (BMP's) will be employed to properly clear and grade the site
and to schedule construction activities. Before any construction begins on-site, erosion control facilities
shall first be installed. The planned construction sequence is as follows:
1. Install filter fabric fencing and construction fence.
2. Construct detention ponds with filter fabric fencing around each.
3. During November 1 through March 31, all disturbed areas greater than 5,000 sf that are to
be left unworked for more than twelve (12) hours shall be stabilized by one of the
following: mulch, sodding or plastic covering.
4. Install storm drainage system.
5. Provide catch basin inlet protection by installing filter fabric under grates of all inlets to
drainage system.
6. Landscape, sod and/or seed and mulch all disturbed areas.
7. Flush storm drainage system.
8. Maintain all erosion control facilities until the entire site is stabilized and silt runoff ceases.
SECTION 2 -TRAPPING SEDIMENT
The soils on-site belong to the Spanaway group and have a low erosion potential according to the SCS.
In those areas where the parcel slopes toward the adjoining property, filter fabric fence will be used to
control erosion and off-site runoff.
The contractor will not be allowed to leave disturbed areas greater than 5,000 sf uncovered during the
rainy season from November 1 through April 30. Soil shall be stabilized within 48 hours after stop of
work in any area that will remain unworked for 30 days or more. Mulch, sodding or plastic covering will
be used to prevent erosion in these areas. During the dry season from May 1 to October 30, exposed soils
should be stabilized within 30 days.
During construction, the contractor will be required to install hlter fabric fencing as needed and limit site
access to one location. Catch basin protection shall be provided by installing filter fabric under grates of
all inlets to drainage system. All disturbed/exposed soils shall be covered with straw or mulch to prevent
erosion in these areas.
SECTION 3 -PERMANENT EROSION CONTROL & SITE RESTORATION
The Shea Group Page 8
August 2001
Yelm Alternative School, Preliminary Drainage Report
All disturbed areas will be asphalted or landscaped with grass, natural vegetation or trees per the
development plans.
SECTION 4 -GEOTECHNICAL ANALYSIS AND REPORT
The proposed infiltration facilities are not located within 50' of a slope 15% or greater; therefore, a
Geotechnical Analysis and report addressing slope stability was not deemed necessary.
SECTION 5 -INSPECTION SEQUENCE
In addition to City inspections, the Project Engineer shall inspect the facilities related to stormwater
treatment, erosion control, storage and conveyance during construction. At a minimum, the following
items shall be inspected at the time specified:
1. The erosion control facilities shall be inspected before the start of construction to ensure
the following structures are in place:
a. Filter Fabric Fences
b. Catch Basin Filters
2. The conveyance systems will be inspected after construction of the facility, but before the
project is completed to ensure the following are in working order:
a. Road and Parking Lot Drainage.
b. Catch Basins
c. Infiltration Pond and Wet Ponds
d. Roof Drywells
3. The permanent site restoration measures shall be inspected after landscaping is completed.
A final inspection will be performed to check final grades, settings of control structures and all necessary
information to complete Engineer's Construction Inspection Report to meet City of Yelm's requirements
for inspection and reporting.
SECTION 6-CONTROL OF POLLUTANTS OTHER THAN SEDIMENTS
Washout from concrete trucks shall not be dumped into the storm drain, or onto soil and pavement, which
carries stormwater runoff. It will be dumped into a designated area to be later backfilled or hardened and
broken up for disposal into a dumpster. The Contractor will be required to designate a washdown area for
equipment and concrete trucks.
The Shea Group Page 9
August 2001
Yelm Alternative School, Preliminary Drainage Report
PART III MAINTENANCE PLAN
SECTION 1 -REQUIRED MAINTENANCE
The following pages contain maintenance needs for most of the components that are part of the
drainage system. A checklist should be completed for all system components on the following
schedule:
M Monthly from November through April.
A. Once in late summer (preferably September).
S. After any major storm (use 1" in 24 hours as a guideline) items marked "S" only.
Using photocopies of these pages, check off the problems looked for each time an inspection was
performed. Add comments or problems found and actions taken. Keep these "Checked" sheets on
file, as they will be used to write the annual report (due in May). Some items do not need to be
looked at every time an inspection is done. Use the suggest frequency at the left of each item as a
guideline for inspections.
The jurisdiction is available for technical assistance. Please do not hesitate to call, especially if a
potential problem exists.
The Shea Group Page 10
August 2001
Yelm Alternative School, Preliminary Drainage Report
ATTACHMENT "A": MAINTENANCE PROGRAM
Maintenance Checklist for Conveyance Systems (Pipes and Swales)
Frequency Drainage ~ Problem Conditions to Check For Conditions That
System Should Exist
Feature
M.S. Pipes J Sediment & Accumulated sediment Pipe cleaned of all
debris that exceeds 20% of the sediment and debris.
diameter of the pi e.
M ~J Vegetation Vegetation that reduces All vegetation
free movement of water removed so water
through pipes. flows freely.
A ~I Damaged Protective coating is Pipe repaired or
(rusted, bent damaged, rust is causing replaced.
or crushed) more than 50%
deterioration to any part
of pipe.
M J Any dent that Pipe repaired or
significantly impedes replaced.
flow (i.e., decreases the
cross-section area of pipe
by more then 20%).
M J Pipe has major cracks or Pipe repaired or
tears allowing replaced.
groundwater leakage.
M.S. Swales Trash & Dumping of yard wastes Remove trash and
debris such as grass clippings debris and dispose as
and branches into Swale. prescribed by County
Unsightly accumulation Waste Management
ofnon-degradable Section.
materials such as glass,
plastic, metal, foam and
coated aper.
M Sediment Accumulated sediment Swale cleaned of all
buildup that exceeds 20% of the sediment and debris
design depth. so that it matches
design.
The Shea Group Page 11
August 2001
Yelm Alternative School, Preliminary Drainage Report
M Vegetation Grass cover is sparse and Aerate soils and
not growing weedy or areas are reseed and mulch bare
or overgrown with woody areas. Maintain grass
overgrown vegetation. height at a minimum
of 6" for best
stormwater treatment.
Remove woody
growth, recontour and
reseed as necessary.
M,S Erosion See ponds checklist See ponds checklist
damage to
slopes
M Conversion Swale has been filled in If possible, speak with
by or blocked by shed, homeowner and
homeowner woodpile, shrubbery, etc. request that swale
to area be restored.
incompatible Contact City to report
use problem if not
rectified voluntarily.
A Swale does Water stands in swale or A survey maybe
not drain flow velocity is very needed to check
slow. Stagnation occurs. grades. Grades need
to be in 1% range if
possible. If grade is
less than 1%,
underdrains may need
to be installed.
If you are unsure whether a problem exists, please contact the jurisdiction and ask for technical assistance.
Comments:
Key: A =Annual (Mazch or April preferred)
M =Monthly (see schedule)
S =After major storms
The Shea Group Page 12
August 2001
Yelm Alternative School, Preliminary Drainage Report
ATTACHMENT "A": MAINTENANCE PROGRAM
Maintenance Checklist for Catch Basins and Inlets
Feature Drainage ~J Problem Conditions to Check For Conditions That
System Should Exist
Feature
M.S. General J Trash, debris Trash or debris in front No trash or debris
and sediment of the catch basin located immediately in
in or on basin opening is blocking front of catch basin
capacity by more than opening. Grate is kept
10%. clean and allows water
to enter.
M J Sediment or debris (in No sediment or debris
the basin) that exceeds in the catch basin.
1/3 the depth from the Catch basin is dug out
bottom of basin to invert and clean.
of the lowest pipe into or
out of the basin.
M.S. ~1 Trash or debris in any Inlet and outlet pipes
inlet or pipe blocking free of trash or debris.
more than 1/3 of it's
height.
M ,I Structural Corner of frame extends Frame is even with
damage to more than 3/4" past curb curb.
frame and/or face into the street (if
top slab applicable).
M ~J Top slab has holes larger Top slab is free of
than 2 inches or cracks holes and cracks.
wider than 1/4" (intent is
to make sure all material
is running into the
basin).
M ~l Frame not sitting flush Frame is sitting flush
on top slab, i.e., on top slab.
separation of more than
3/4" of the frame from the
top slab.
The Shea Group Page 13
August 2001
Yelm Alternative School, Preliminary Drainage Report
A ~I Cracks in Cracks wider than 1/2" Basin replaced or
basin and longer than 3', any repaired to design
walls/bottom evidence of soil particles standards. Contact a
entering catch basin professional engineer
through cracks or for evaluation.
maintenance person
judges that structure is
unsound.
A J Cracks wider than 1 /2" No cracks more than
and longer than 1' at the 1/4" wide at the joint
joint of any inlet/outlet of inlet/outlet pipe.
pipe or any evidence of
soil particles entering
catch basin through
cracks.
A J Settlement/mi Basin has settled more Basin replaced or
s-alignment than 1" or has rotated repaired to design
more than 2" out of standards. Contact a
alignment. professional engineer
for evaluation.
M.S. ~I Fire hazard or Presence of chemicals No color, odor or
other such as natural gas, oil sludge. Basin is dug
pollution and gasoline. out and clean.
Obnoxious color, odor or
sludge noted.
M.S. ~I Outlet pipe is Vegetation or roots No vegetation or root
clogged with growing in inlet/outlet growth present.
vegetation pipe joints that is more
than 6" tall and less than
6" apart.
If you are unsure whether a problem exists, please contact the Jurisdiction and ask for technical assistance.
Comments:
Key: A =Annual (March or April preferred)
M =Monthly (see schedule)
S =After major storms
The Shea Group Page 14
August 2001
Yelm Alternative School, Preliminary Drainage Report
ATTACHMENT "A": MAINTENANCE PROGRAM
Maintenance Checklist for Grounds (Landscaping)
Frequency Drainage J Problem Conditions to Check Conditions That
System For Should Exist
Feature
M General ,~ Weeds Weeds growing in Weeds present in less
(nonpoisonou more than 20% of the than 5% of the
s) landscaped area (trees landscaped area.
and shrubs only).
M J Safety hazard Any presence of poison No poisonous
ivy or other poisonous vegetation or insect
vegetation or insect nests present in
nests. landscaped area.
M.S. ~l Trash & Dumping of yard Remove trash and
debris wastes such as grass debris and dispose as
buildup in clippings and branches. prescribed by City
open space Unsightly Waste Management
accumulation of non- Section.
degradable materials
such as glass, plastic,
metal, foam and coated
paper.
M ~l Missing or Any defect in the fence Fence is mended or
broken or screen that permits shrubs replaced to form
parts/dead easy entry to a facility. a solid barrier to entry.
shrubbery
M.S. ~ Erosion Erosion has resulted in Replace soil under
an opening under a fence so that no
fence that allows entry opening exceeds 4" in
by people or pets. height. Causes of
erosion identified and
steps taken to slow
down and/or spread out
the water. Eroded
areas are filled,
contoured, and seeded.
M J Unruly Shrubbery is growing Shrubbery is trimmed
vegetation out of control or is and weeded to provide
infested with weeds. appealing aesthetics.
Do not use chemicals
to control weeds.
The Shea Group Page 15
August 2001
Yelm Alternative School, Preliminary Drainage Report
A Trees and J Damage Limbs or parts of trees Trim trees/shrubs to
shrubs or shrubs that are split restore shape. Replace
or broken which affect trees/shrubs with
more than 25% of the severe damage.
total foliage of the tree
or shrub.
M ~ Trees or shrubs that Replant tree, inspecting
have been blown down for injury to stem or
or knocked over. roots. Replace if
severely damaged.
A J Trees or shrubs which Place stakes and
are not adequately rubber-coated ties
supported or are around young
leaning over, causing trees/shrubs for
exposure of the roots. support.
If you are unsure whether a problem exists, please contact the Jurisdiction and ask for technical assistance.
Comments:
Key: A =Annual (March or April preferred)
M =Monthly (see schedule)
S =After major stottns
The Shea Group Page 16
August 2001
Yelm Alternative School, Preliminary Drainage Report
ATTACHMENT "A": MAINTENANCE PROGRAM
Maintenance Checklist for Ponds
Frequency Drainage ~1 Problem Conditions to Check Conditions That
System For Should Exist
Feature
M,S General ~l Trash & Clumping of yard Removed trash and
debris buildup wastes such as grass debris and dispose as
in pond. clippings and prescribed by City
branches into basin. Waste Management
Unsightly Section
accumulation of
nondegradable
materials such as
glass, plastic, metal,
foam and coated
a er..
M,S ~l Trash rack Bar screen over outlet Replace screen.
plugged or more than 25% Remove trash and
missing covered by debris or debris and dispose as
missing. prescribed by City
Waste Management
Section.
M ~ Poisonous Any poisonous Remove poisonous
vegetation vegetation which may vegetation. Do not
constitute a hazard to spray chemicals on
the public. Examples vegetation without
of poisonous obtaining guidance
vegetation include: from the Cooperative
tansy ragwort, poison Extension Service
oak, stinging nettles, and approval from
devilsclub. the Ci
M,S ~ Fire hazard or Presence of chemicals Find sources of
pollution such as natural gas, oil pollution and
and gasoline, eliminate them.
obnoxious color, odor Water is free from
or sludge noted. noticeable color,
odor or
contamination.
The Shea Group Page 17
August 2001
Yelm Alternative School, Preliminary Drainage Report
M ,l Vegetation For grassy ponds, For grassy ponds,
not growing grass cover is sparse selectively thatch,
or is and weedy or is aerate, and reseed
overgrown overgrown. For ponds. Grass cutting
wetland ponds, plants unnecessary unless
are sparse or invasive dictated by
species are present. aesthetics. For
wetland ponds,
handplan nursery-
grown wetland plants
in bare areas.
Contact the
Cooperative
Extension Service for
direction on invasive
species such as
purple loosestate and
reed canary grass.
Pond bottoms should
have uniform dense
coverage of desired
plants ecies.
M ~J Rodent holes Any evidence of Rodents destroyed
rodent holes if facility and dam or berm
is acting as a dam or repaired. Contact the
berm, or any evidence Thurston County
of water piping Health Department
through dam or berm for guidance.
via rodent holes.
M ~l Insects When insects such as Insects destroyed or
wasps and hornets removed from site.
interfere with Contact Cooperative
maintenance Extension Service for
activities, or when guidance.
mosquitoes become a
nuisance.
A ~I Tree growth Tree growth does not Trees do not hinder
allow maintenance maintenance
access or interferes activities.
with maintenance Selectively cultivate
activity (i.e., slope trees such as alders
mowing, silt removal, for firewood.
or equipment
movements). If trees
are not interfering
with access, leave
trees along.
The Shea Group Page 18
August 2001
Yelm Alternative School, Preliminary Drainage Report
M Side slopes J Erosion on Check around inlets Find causes of
of pond berms or at and outlets for signs erosion and eliminate
entrance/exit. of erosion. Check them. Then slopes
berms for signs of should be stabilized
sliding or settling. by using appropriate
Action is needed erosion control
where eroded damage measure(s); e.g., rock
over 2 inches deep reinforcement,
and where there is planting of grass,
potential for continued compaction.
erosion.
M Storage area ~I Sediment Accumulated Sediment cleaned out
buildup in sediment that exceeds to designed pond
pond 10% of the designed shape and depth;
pond depth. Buried or pond reseeded if
partially buried outlet necessary to control
structure probably erosion.
indicates significant
sediment de osits.
A Pond dikes J Settlements Any part of dike Dike should be build
which has settled 4 back to the design
inches lower than the elevation.
design elevation.
A Emergency ~J Rock missing Only one layer of rock Replace rocks to
overflow/ exists above native design standards.
Spillway soil in area 5 square
feet or larger, or any
exposure of native
soil.
One Time Emergency J Overflow Side of pond has no Contact City for
overflow/ missing area with large rocks guidance.
Spillway to handle emergency
overflows.
If you are unsure whether a problem exists, please contact the Jurisdiction and ask for technical assistance.
Comments:
Key: A =Annual (March or April preferred)
M =Monthly (see schedule)
S =After major storms
The Shea Group Page 19
August 2001
Yelm Alternative School, Preliminary Drainage Report
SECTION 2 -RESPONSIBLE ORGANIZATION
The property owner (and successors) is responsible for the operation and maintenance of on-site drainage
facilities. See the commercial maintenance agreement in Appendix VII.
SECTION 3 -VEGETATION MANAGEMENT PLAN
All disturbed pervious areas within the site will be landscaped to provide an aesthetically pleasing
environment.
SECTION 4 -SOURCE CONTROL
Warning signs (e.g., "Dump No Waste -Drains to Ground Water") will be painted or embossed on or
adjacent to all storm drain inlets and will be repainted periodically as necessary.
The Shea Group Page 20
August 2001
COVER SHEET
STORM DRAINAGE FACILITY CALCULATIONS:
Description: Yelm Alternative School
Date: 8/10/2001
Job #: 242-4175-001
Prepared by: Thomas A. Trotter. P.E.
The following calculations are based on the requirements contained in the DOE Stormwater Management
for Puget Sound Basin (1992 Edition)
rnTei eoce•
Cultivated Land (Winter) _
Mountain Open Areas (Low Brush /Grassland) _
Meadow /Pasture =
Wood or Forest (Undisturbed) _
Wood or Forest (Young 2nd Growth /Brush) _
Orchard (With Cover Crop) _
Lawns, Parks, Golflinks, etc. (75% or More Grass Cover) _
Lawns, Parks, Golflinks, etc. (50% to 75% Grass Cover) _
Residential With 1.0 DU/GA (15% Impervious) _
Residential With 1.5 DU/GA (20% Impervious) _
Residential With 2.0 DU/GA (25% Impervious) _
Residential With 2.5 DU/GA (30°/ Impervious) _
Residential With 3.0 DU/GA (34% Impervious) _
Residential With 3.5 DU/GA (38% Impervious) _
Residential With 4.0 DU/GA (42% Impervious) _
Residential With 4.5 DU/GA (46% Impervious) _
Residential With 5.0 DU/GA (48% Impervious) _
Residential With 5.5 DU/GA (50% Impervious) _
Residential With 6.0 DU/GA (52% Impervious) _
Residential With 6.5 DU/GA (54% Impervious) _
Residential With 7.0 DU/GA (56% Impervious) _
Gravel Roads /Car Parks =
Dirt Roads /Car Parks =
Impervious Surfaces (98% Impervious) _
Open Water Bodies (100% Impervious) _
Total Area =
TREATMENT DESIGN AND BASIN INFORMATION SUMMARY:
Sub-Basin Total Impervious Area Excluding
Water Bodies = acres
1 1.51
2 0.47
Total = 1.98
STORAGE DESIGN AND BASIN INFORMATION SUMMARY:
Sub-Basin Total Impervious Area =
acres Disturbed Pervious Area =
acres Total Area =
acres
1 1,51 0.72 2:23
2 0.47 0.00 0:47
Total = 1.98 0.72 2.70
ON-SITE AREA:
Impervious Building FootprinVPond Area: 0.47 ac
Impervious Road/Sidewalk/Parking LoUAlley Area: 0.87 ac
Disturbed Pervious Area: 0.60 ac
Undisturbed Pervious Area: 0.00 ac
Uncaptured Runoff Area: 0.00 ac
Total 1:94 ac
OFF-SITE AREA:
Impervious Road/Parking Lot/Alley/Sidewalk Area: O.G4 ac
Disturbed Pervious Area: 0.12 ac
Total - "0:76'ac
SOIL CLASSIFICATION:
SCS Soils: Hydrologic Group: Design Infiltration Rate:
Spanaway B 20 in/hr
= 0.00 ac
= 0.00 ac
= 0.00 ac
= 0.00 ac
= 0.00 ac
= 0.00 ac
= 0.72 ac
= O OO ac
= 0.00 ac
= 0.00 ac
= 0.00' ac
= 0.00 ac
= o.oo ac
= o.oo ac
= o.00 ac
= o.oo ac
= o.oo ac
= o.oo ac
= 0.00 ac
= 0.00 ac
= 0.0o ac
= 0.05 ac
= 0.00 ac
= 1.93 ac
= 0.0o ac
2.70. ac
Site Infiltration Rate:
40.0 in/hr
STORMWATER TREATMENT
CONVENTIONAL WET POND:
Description: Yelm Alternative School -Basin #1
Date: 8/10/2001
Job #: 242-4175-001
Reference: -1992 DOE Stormwater Management for Puget Sound Basin (Volume 3)
-Per section III-4.4.1 of the DOE:
1) Identify Required Wetpond Volume:
Total Tributary Impervious Area = 1.51 ac.
Total Tributary Disturbed Pervious Area = 0.72 ac.
Required Volume To Treat 6 Month, 24 Hour Storm Event = _ 9,667 c.f.
2) Determine Wetpond Dimensions (Table III-4.2):
Note: -Wetpond shall be divided into at least two cells, preferably three, approximately equal in size.
-First cell should be 3' deep.
-Cells should be approximately equal in size.
-Minimum depth is 3 feet, maximum depth is 6 feet.
-All ponds greater than 18" or steeper than 4:1 shall be fenced.
-Minimum length to width ratio shall be 3:1, preferably 5:1.
Permanent Pool Volume Provided:
From StormSHED
CELL #1 CELL #2 CELL #3
Proposed Wetpond Length =
Proposed Wetpond Width =
Proposed Wetpond Bottom Area =
Proposed Length/Width Ratio =
Proposed Wetpond Bottom Elevation =
Proposed Wetpond Depth =
Proposed Wetpond Freeboard =
Proposed Wetpond Side Slope =
Proposed Wetpond Cell Volume =
Percentage of Cell Volume =
Total Volume = 12,152 cf > Required Volume =
61ft 66ft Oft
42 ft 20 ft 0 ft
1,228 sf 429 sf 0 sf
332 ft 331 ft 0 ft
aft Oft Oft
1ft 1ft Oft
3 :1 3 :1 0 :1
6,485 cf 5,667 cf 0 cf
53% 47% 0.%
9,667 cf, Therefore is Adequate.
BASIN 1 - 6-MO STORM EVENT
(WETPOND DESIGN)
BSN 1 Event Summary:
BasinlD Peak Q
------- (cfs)
BSN 1 0.64
Drainage Area: BSN 1
Hyd Method: SCS Unit Hyd
Peak Factor: 484.00
Storm Dur: 24.00 hrs
Area
Pervious 0.7200 ac
Impervious 1.5100 ac
Total 2.2300 ac
Supporting Data:
Pervious CN Data:
LANDSCAPING
Impervious CN Data:
IMPERVIOUS ROAD & S/W
Pervious TC Data:
Flow type: Description:
Fixed None Entered
Impervious TC Data:
Flow type: Description:
Fixed None Entered
Peak T Peak Vol Area Method Raintype Event
(hrs) (ac-ft) ac /Loss
8.00 0.2219 2.23 SCS/SCS TYPE1A Other
Loss Method: SCS CN Number
SCS Abs: 0.20
Intv: 10.00 min
CN TC
80.00 0.08 hrs
98.00 0.08 hrs
80.00 0.7200 ac
98.00 1.5100 ac
Length: Slope: Coeff: Travel Time
0.00 ft 0.00% 5.0000 5.00 min
Length: Slope: Coeff: Travel Time
0.00 ft 0.00% 5.0000 5.00 min
STORAGE
INFILTRATION POND:
1)
2)
Description: Yelm Alternative School -Basin #1
Date: 8!10!2001
Job #: 242-4175-001
Reference: 1992 DOE Stormwater Management for Puget Sound Basin (Section III-3.6.3)
SITE SUITABILITY CRITERIA PERTAINING TO STREAMBANK EROSION CONTROL ONLY:
GL-1 Soil Suitability
Min. infiltration rate of 0.5 inches per hour.
Infiltration systems shall not use fill material or be placed over fill material.
GL-2 Depth to Bedrock, Water Table, or Impermeable Layer
Bottom of facility shall be at least 3 feet above limiting layer.
GL-3 Setback requirements
Infiltration facilities should be at least 100 feet from drinking water wells, septic tanks or drainfields,
and springs used for drinking water supplies.
Infiltration facilities should be at least 20 feet downslope and 100 feet upslope from building foundations.
GL-4 Land Slope
Infiltration facilities can be located on slopes up to 15%.
Infiltration facilities should be at least 50 feet away from slopes greater than 15%.
GL-5 Drainage Area
Infiltration basins shall have a maximum drainage area of 50 acres.
GL-6 Control of Siltation
Final construction of infiltration trenches shall not be done until) after site construction is finished
and site is stabilized.
Infiltration facilities should not be used for temporary sediment traps.
SIZING INFILTRATION FACILITY:
Representative Site Infiltration Rate (f) = 40.00 in/hr Table III-3. Sandy Gravel >2'
Factor of Safety (FS) = 2.0
Design Infiltration Rate (Fd) = 20.00 in/hr = f / FS
0.000463 fps
Distance From Bottom to Bedrock, Till, or Water Level (L) = 3.0 ft
Bottom Surface Area of Pond (As) = 1;605 sf
Height of Water Above Bottom of Gallery (h) = Varies
Use Darcy's Law (equation 3) to Calculate Infiltration Rate in cubic feet per second. (See Following Table).
Q=[(Fd)x(h+L1)x(As)]/L1
h
ft I
ft/ft O
cfs S
cf
0.0 1.00 0.743 0
1.0 1:33 0.991 1,916
2.0 1.67 1.238 ..4,480
3.0 2.00 ; .1.486 7,750
4.0 2.33° 1.734 11,783
Using StormSHED, model facility and check for complete infiltration of the 10-yr storm in 24 hours
and the 100-yr storm within 48 hours.
STORAGE
Min. Storage Volume Required for 10 yr, 24 hr Storm = 1,783 cf
Maximum Depth of Water in Gallery = 0.93 ft
Min. Storage Volume Required for 100 yr, 24 hr Storm = 3,985 cf
Maximum Depth of Water in Gallery = 1.19 ft
Time Required to Infiltrate Gallery After 10-yr Storm = 0.6 hr < 24 hours
Time Required to Infiltrate Gallery After 100-yr Storm = 0.7 hr < 48 hours, Therefore is Adequate.
3) STORMWATER STORAGE VOLUME PROVIDED:
Infiltration Pond.
Stage Elevation Stage Storage Volume Total Storage Volume
Pond Bottom 332.0 ft 0 cf 0 cf
333.0 ft 1',916 cf 1,916 cf
334.0 ft 2,564 cf 4,480 cf
Pond Top '' 335.0 ft 3,270 cf 7,750 cf
Freeboard 336.0 ft 4,033`-cf 11,783 cf
Design Pond Storage Capacity = 7,750. cf
Total Pond Storage Capacity = 11,783.. cf
Storage Volume = 7,750 c.f. > Required Volume = 3,985'. c.f.
BASIN 1 -10=YR & 100-YR STORM EVENTS
(INFILTRATION POND DESIGN)
RLPCOMPUTE [LPN 1] SUMMARY
10 yr MatchQ=PeakQ= 1.9016 cfs Peak Out Q: 0.9737 cfs -Peak Stg: 332.93 ft -Active Vol: 1782.79 cf
100 yr MatchQ=PeakQ= 2.8339 cfs Peak Out Q: 1.1903 cfs -Peak Stg: 333.81 ft -Active Vol: 3985.03 cf
Running K:\4175-Yelm Comm. SchoolslContract\Yelm Alternative School\Phase 01-SUP Support\stormshed\LPN 1
Report.pgm on Thursday, August 09, 2001
Summary Report of all RLPooI Data
Project Precips
[2 yr] 2.80 in
[5 yr] 3.75 in
[10 yr] 4.35 in
[25 yr] 5.10 in
[100 yr] 6.15 in
[Other] 1.79 in
BASLIST2
[BSN 1] Using [TYPE1A] As [10 yr]
[BSN 1] Using [TYPE1A] As [100 yr]
LSTEND
BasinlD PeakQ Peak T Peak Vol Area Method Raintype Event
------- (cfs) (hrs) (ac-ft) ac /Loss
BSN 1 1.9016 8.00 0.6538 2.23 SCS/SCS TYPEIA 10 yr
BSN 1 2.8339 8.00 0.9731 2.23 SCS/SCS TYPEIA 100 yr
BASLIST [TYPE1A] AS [10 yr] DETAILED
[BSN 1]
LSTEND
Drainage Area: BSN 1
Hyd Method: SCS Unit Hyd Loss Method: SCS CN Number
Peak Factor: 484.00 SCS Abs: 0.20
Storm Dur: 24.00 hrs Intv: 10.00 min
Area CN TC
Pervious 0.7200 ac 80.00 0.08 hrs
Impervious 1.5100 ac 98.00 0.08 hrs
Total 2.2300 ac
Supporting Data:
Pervious CN Data:
LANDSCAPING 80.00 0.7200 ac
Impervious CN Data:
IMPERVIOUS ROAD & S/W 98.00 1.5100 ac
Pervious TC Data:
Flow type: Description: Length: Slope: Coeff: Travel Time
Fixed None Entered 0.00 ft 0.00% 5.0000 5.00 min
Impervious TC Data:
Flow type: Description: Length: Slope: Coeff: Travel Time
Fixed None Entered 0.00 ft 0.00% 5.0000 5.00 min
HYDLIST SUMMARY
[BSN 1-6M0-OUT]
LSTEND
HydID Peak Q
------- (cfs)
BSN1-6M0-OUT 0.97
BSN1-100YR-OUT 1.19
STORLIST
[STO 1 ]
LSTEND
Node ID: STO 1
[BSN 1-100YR-OUT]
Desc: Infiltration Pond
Start EI: 332.0000 ft
Contrib Basin:
Stage Input
332.00 0.00 cf
333.00 1916.00 cf
334.00 4480.00 cf
335.00 7750.00 cf
DISCHLIST
(DIS 1]
LSTEND
Peak T Peak Vol Cont Area
(hrs) (ac-ft) (ac)
8.17 0.6552 2.2300
8.67 0.9738 2.2300
Max EI: 335.0000 ft
Contrib Hyd:
Volume Volume
0.00 cf 0.0000 acft
1916.00 cf 0.0440 acft
4480.00 cf 0.1028 acft
7750.00 cf 0.1779 acft
Control Structure ID: DIS 1 -Stage Discharge rating curve
Descrip: Infiltration Pond
Start EI Max EI Increment
332.0000 ft 335.0000 ft 0.10
Stage Discharge
332.0000 ft 0.7430 cfs
333.0000 ft 0.9910 cfs
334.0000 ft 1.2380 cfs
335.0000 ft 1.4860 cfs
Stormwater Storage
DRYWELLS FOR RESIDENTIAL ROOFS AND CLEAN IMPERVIOUS SURFACES:
Description: Yelm Alternative Schools -- E}A~ ~ ~,
Date: 8/6/2001
Job #: 242-4175-001
Reference : Thurston County.. DDECM, Chapter 8, Table 8.2
Soil Hydrologic Group i B 1
TABLE 8.2:
3roup A and B '125 cf/ 1000 sf of roof area
group C '250 cf/ 1000 sf of roof area
group D "750 cf/ 1000 sf of roof area
Volume includes rock backfill. Trench size may be reduced if oioe or other open
of the rock backfill; contact the jurisdiction for guidance.
tructure replaces a portion
From Table 8.2 and Soil Hydrologic Group B ,minimum storage volume required per 1000 sf of roof
area = 125 cf
Minimum Stormwater Storage Volume Required:
Total impervious roof area = 20;473 sf
Vmin = (impervious roof area/1000) `factor = 2,559' cf
Stormwater Storage Volume Provided:
The required volume of ~ 2,:559 cf will be stored and infiltrated using 2 underground
infiltration drainrock gallery(galleries) 10D' ft. long x 3:5 ft. wide x 4' ft. deep.
V = N(L"W*H) = 2800: cf
Storage Volume = 2,80Q c.f. > Required Volume = 2,559' c.f. Therefore is Adequate.
W
~ T~
C7
Z
~_
Q
U
O
J
I---
U
W
O
J
O
O
Q.. _
Q ~
~" ~
~_ Z
Z H
_U J
a
~ ~
J
W
~~
~ c
a
Q E
0
~IL~ ~
V `
m
^1 0
W d
~^~ o
V^J,
W
^
O
O
a
z
w
z
W ~
~
''
J N
m
x
~
~
v
Z
w
~
Z
L11
~`
J ~
U
K
~
~
J
~ ?
2
~
~
U Q
_V
W
~
2 ~
m
N
m
~ ~
2
m
~
I ~~
• ~~X~
~ v
W
K O ~ 3 NI
m ~ z ~ ~,.
~ ~ ~ 0 0
Z ~ Z p NI
m I ¢ ~ ti
O N =
a 0 d cn
N
~ a
O -'
x °
r l H
rTV~~
Vl ~
Z
_O
W
O
d'
LHL W
C~ ~
W
a
z "
a, z
Q
0
w ~
H ~
~ ~
o
F-
c
~ _z
J
W ~
W
K
a
~I ~I I ~
b o
,: m
m ~;
~~
J
O
O
2 ~
U Z
(n Q
J
~Yn
~ o>
~m~
~~rn
zQ
UW3
~v~
-~ ~ ~~ 17
N
O
0
v
w
Q
w
a
m
ZN
O
sWR
K
2
i.L li d
'+ m d
O ~ ~ 'n (n
a
~ o M o
u m rn ~
d ~ N
°1 O O c
(~ o ~ <0 0
/~\ ~~
VJ d C
W
~/^, O •
~ l0 C
~/ ! ~
C N C
C
J ~ ~',
Q Q •
c
~ 3 ~
u ~
c0 J ~'
^ ~ ~ ~
CITY OF YELM REGION
FACILITY SUMMARY FORM
Complete one (1) for each facility (detention/retention, coalescing plate
filter, etc.) on the project site. Attach 8 1/2 x 11 sketch showing location
of facility.
Proponent's Facility Name or Identifier (e.g., Pond A) ..............: See Part 6
Name of Road or Street to Access Facility :...................... Jefferson Street
Hearings Examiner Case Number :........................... .
Development Rev. Project No.Bldg. Permit No .:................ .
Parcel Numbers :........................................... 64421800100, 64421701000,
64400100100,64400600100,
64400600300,64421700900,
64421700800,64421700600
To be completed by Utility Staff:
Utility Facility Number
Project Number (num)
Parcel Number Status: (num, I ch)
0, Known; 1, Public; 2 Unknown;
3, Unassigned
Basin and Subbasin: (num, 6ch)
(2ch for basin, 2ch for Subbasin, 2ch future
Responsible jurisdiction: (alpha, lch)
Part 1 - Proiect Name and Proponent
Project Name ................................
Project Owner ...............................
Project Contact ............................. .
Address ...................................
Phone .....................................
Project Proponent: (if different) ................. .
Address ................................... .
Phone .......... ...........................
Project Engineer .............................
Firm .......................................
Yelm Alternative School
Yelm Community Schools
Erling Birkland
P.O. Box 476, Yehn, WA 98597
(360)458-6128
Same
Same
Same
Thomas A Trotter, PE
The Shea Group
(360) 349-3609
Part 2 -Project Location
Section(s) 19
Township 17 N
Range 2 E, Willamette Meridian
Part 3 -Type of Permit Application
Type of permit (e.g., Commercial Bldg.):
Other Permits (circle)
^DOF/W HPA ^COE 404
^COE Wetlands ^DOE Dam Safety
^FEMA ^Floodplain
^Shoreline Mgmt ^Rockery/Retaining Wall
^Encroachment ^Grading
^NPDES
^Other
Other Agencies (Federal, State, Local, etc.) that have had or will review this Drainage
Erosion Control Plan:
Part 4 -Proposed Project Description
What stream basin is this project in (e.g., Percival, Woodland):.... Yelm Creek
Project Size, acres ...................................... 2.70 ac
Zoning ............................................... Central
Business
District
On-site:
Residential Subdivision:
Number of Lots :................................. .
Lot size (average), acres :......................... .
Building Permit /Commercial :......................... .
Building Footprint, acres :.......................... 0.47
Concrete Paving, acres ::....................... 0.04
Gravel Surface, acres ::....................... 0.05
Lattice Block Paving, acres :.:...................... .
Public Roads (including gravel shoulder), acres:.......... .
Private Roads (including gravel shoulder), acres :....... ... 0.78
On-site Impervious Surface Total, acres :................. 1.34
Part 5 -Pre-Developed Project Site Characteristics
Stream through site, y/n: ................................... No
Name: ............................. ..........
DNR Type: ........................................
Type of feature this facility discharges to (i.e., lake,
stream, intermittent stream, pothole, roadside ditch,
sheetflow to adjacent private property, etc.):
Infiltration into ground, y/n :.................... ..... .
Swales, Ravines, y/n ::........................... .
Steep slopes (steeper than 15%) y/n :................ .
Erosion Hazard, y/n :............................ .
100 yr. Floodplain, y/n :..................... ..... .
Lakes or Wetlands, y/n :............................
Seeps/Springs, y/n ::............................. .
High Groundwater Table, y/n :..................... .
Wellhead Protection or Aquifer Sensitive Area, y/n:...... .
Groundwater
Yes
No
No
Slight
No
No
No
No
No