Storm Drainage ReportStorm Drainage Report
Project Iaformatioa
Project:
Buckhorn Estates Subdivision
8945 Mountain View Road SE
Yelm, WA 98597
June 2003
Preliminary Plat Residential Subdivision
Prepared for: Project Fore
Contact: Dan Kinsman
PO Box 15113
Olympia, Washington 98511
(360) 978-4907
Reviewiag Ageacy
Jurisdiction:
Project Number:
Project Contact
City of Yehn
TIP 21713310101
Project Eagiaeer
Prepared by: BDG, LLC
15345 Slwwood Blvd Suite 302
Tukwila, Washington 98188
Contact: Karl Lundberg, PE
Job #: 03105
File Number: 03105 drainage report.doc
PROJECT ENGINEERS CERTIFICATION: 1 hereby certify that this Drainage
Report for this project has been prepared by me or under my supervision and meets the
intent of the Thurston County Drainage Design and Frosicm Control Manual (I~I~F.Clv1),
unless noted otherwise, 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 for this development.
Table of Contents
PART I STORM DRAINAGE REPORT
SECTION 1 -PROPOSED PROJECT DESCRIl'TION .............................. 2
SECTION 2 -EXISTING CONDITIONS .................................. .................. 4
SECTION 3 -INFILTRATION RATES/SOILS REPORT ........ .................. 5
SECTION 4 -WELLS AND SEPTIC SYSTEMS ...................... .................. 5
SECTION 5 -FUEL TANKS ..................................................... .................. 5
SECTION 6 -SUB-BASIN DESCRIPTION .............................. .................. 5
SECTION 7 -ANALYSIS OF 100 YEAR FLOOD ..................................... 5
SECTION 8 -AESTHETIC CONSIDERATIONS ...................................... 6
SECTION 9 -DOWNSTREAM ANALYSIS AND FACILITY SIZING..... 6
SECTION 10 -COVENANTS, DEDICATIONS, EASEMENTS ................ 6
SECTION 11 -ARTICLES OF INCORPORATION ................................... 6
PART 11 EROSION CONTROL REPORT
SECTION 1 -CONSTRUCTION SEQUENCE AND PROCEDURE.......... 7
SECTION 2 -TRAPPING SEDIlVIENT ....................................................... 7
SECTION 3 -EROSION CONTROL & SITE RESTORATION ................. 8
SECTION 4 -GEOTECHNICAL ANALYSIS AND REPORT ................... 8
SECTION 5 -INSPECTION SEQUENCE .................................................. 8
SECTION 6-CONTROL OF POLLUTANTS ............................................. 8
PART III MAINTENANCE PLAN
SECTION 1 -REQUIltED MAINTENANCE ............................................. 9
SECTION 2 -RESPONSIBLE ORGANIZATION .................................... 19
APPENDICES
Appendix I- Vicinity Map
Appendix II -Drainage Plan
Appendix III -Facility Sununary Fotm
Appendix IV -Residential Maintenance Agreement
Appendix V -Soils Rcport
SECTION 3 -VEGETATION MANAGEMENT PLAN ............................ 19
SECTION 4 -SOURCE CONTROL .......................................................... 19
Buckhorn Estates, Storm 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), 1994 Edition.
SECTION 1 -PROPOSED PROJECT DESCRIPTION
Project Proponent: Dan Kinsman
PO Box 15113
Olympia, Washington 98511
(360) 978-4907
Parcel Numbers: 21713310101
Total Site Area: 4.81 acres
Zoned: Residential R-6
Site Address: 8945 Mountain View Rd Yelm, Washington 98597
Required Permits: Grading, Utility, Storm Drainage
Section, Township, Range: Section 13, Township 17N, Range 1 East, W.M.
Thurston County, Washington
The site is located in Thurston County and in the City of Yelm. This project is bordered on the north,
south and west sides by residentally zoned parcels. The south side of the project is bourdered by
Mountain View Road.
'The proposal is to develop this site for 20 residentaal building lots and the existing home and residence
will remain in the same location. The existing property has a single family home, attached gazage and an
out building located approximately 100 feet to the north of the home. This proposal is to add 20
residential building lots, water system, sewer system, storm drainage system and public roadway to serve
these new lots.
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Buckhom Estates, Storm Drainage Report
Storm Drainage Improvements:
This 9.85-acre project has one storm drainage basin that extends to the boundaries of the project. The
drainage basin will convey stormwater from the asphalt parking areas, landscape areas, and landing area
to a wetpond and an infiltration pond. The total area for the basin is 9.85 acres. This area is the project
area up to and including the properly line. All roof areas will be connected to underground drywells.
These drywells will be sized according to the 1994 DDECM. In the following basin summary all area
within the drainage basin has been accounted for. The Pre-Development Basin Summary has been
included for reference of the current ground cover.
Pre-Development Basin Summary
Basin Area (Ac1
Impervious 0.000
Buildings 0.068
Disturbed Pervious 0.200
Undisturbed Pervious 4.542
Total 4.810
Post Development Basin Summary
Basin Area (Act
Impervious 1.329
Buildings 0.964
Disturbed Pervious 2.200
Undisturbed Pervious 0.317
Total 4.810
Stormwater Treatment:
Stormwater treatment for this project will be accomplished utilizing an open wet pond. The wet
pond will provide settling treatment of the runoff using a permanent pool of water. This wetpond
will provide treatment only and the infiltration pond will provide retention. The wet pond has been
designed per section 8.3 of the1994 DDECM. The wet pond has been sized utilizing 2.5% of the
impervious surfaces of the drainage basin. The building roof areas were not included in the
impervious calculations. The wetpond shall have a minimum dead storage of 3 feet and be lined
with 4 to 6 inches of silt loam, sandy clay loam or organic muck. The existing ground has been
tested to exceed the minimum unlined field saturation percolation rate specified in the drainage
manual.
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Buckhom Estates, Storm Drainage Report
Treatment Area Summa
Basin # Impervious Area Treatment
Re aired Treatment
Provided
Basin 1.522 ac. 1,657 sf. 1,811 sf.
Stormwater Storage:
Storage requirements were based on the Soil Survey of Thurston County and infiltration testing
completed by .The soil report can be located in the appendix of this report. A design
infiltration rate of 20 inches/hour was recommended and utilized for this stormwater design. The
DDECM required 3,000 cf of storage for each acre of impervious area and 1,000 cf of storage for
each acre of disturbed pervious area. This is based on an infiltration rate of 20 in/hr and Table 4.1
of the DDECM.
Treated runoff from the wet pond will flow through a rock filter window and into the infiltration
pond. This pond is approx. 40' wide X 80' long at the pond bottom. The required storage depth
for this pond has been set at 5' deep. The slopes of the pond have been designed at 3:1 slope. The
infiltration pond bottom has been set at 186.00 and the max water surface, as a function of project
site infiltration of 20 in/hr will be 191.00.
The infiltration pond has a volume of 6,268 cubic feet, which exceeds the minimum volume of
6,180 cubic feet.
Stour a Ca aci Summa
Basin # Impervious Area Disturbed Pervious
Area Storage Volume
R aired Storage Volume
Provided
Basin 1.329 ac. 2.194 ac. 6,180 c.f. 6,268 c.f.
(All acre numbers have been rounded to the neazest hundredth of an acre. Actual volume has been
calculated using the exact numbers)
SECTION 2 -EXISTING CONDITIONS
This site is mostly an open undisturbed pervious ground cover. Currently the site is open prairie ground
with no trees. The existing buildings and asphalt are located in the southeast corner of the site. The
building and asphalt were constructed approx. 3 years ago. The remaining site azea is undeveloped. The
undeveloped portion is relatively flat with gently sloping Z% grade to a low point located next to
Mountian View Road.
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Buckhorn Estates, Storm Drainage Report
There are no drainage channels within or near the site and no off-site drainage enters the 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 a
Nisqually (73). This soil type features Hydrologic Group A chazacteristics. Refer to the Appendix for the
SCS Soils Map.
On-site soil tests have been completed for this drainage report. Soil tests have been performed by
.This report is located in appendix of this report.
SECTION 4 -WELLS AND SEPTIC SYSTEMS
The existing site has one well located on the property. This well will be decommissioned prior to
subdivision approval.
The existing home's septic system was identified during the site investigation. This septic system found
shall be removed in accordance with Thurston County Department of Health Standazds.
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 DESCRII'TION
This project has been designed to infiltrate and provide treatment for all stormwater produced by this site.
There will be no runoff from the project site for the 100-year, 24-hour storm event. There is no significant
off-site runoff or up stream basin to address for this project application
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 this site shows this site outside the 100-yeaz
flood plain.
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Buckhorn Estates, Storm Drainage Report
SECTION 8 -AESTHETIC CONSIDERATIONS FOR STORMWATER FACILITIES
All disturbed areas will be vegetated. The stormwater infiltration facilities have been designed to be
located in the rear of the industrial area and will not be visible from the adjacent roadway. Aesthetics of
facilities will be in keeping with similar industrial projects in the area.
SECTION 9 -DOWNSTREAM ANALYSIS AND FACILITY SIZING
This stormwater design contains all runoff on-site. The infiltration pond and wetpond have an additional
3 to 4 feet of free board before storm water will overtop the drainage facility. Given these parameters it
appears that a downstream analysis should not be necessary with the safety factors involved.
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 Thurston County is
included in the Appendix of this report that will allow the County access to facilities. The owner is
responsible for performing regular maintenance of the storm drainage facilities. Thurston County will
provide techiucal 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.
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Buckhorn Estates, Storm Drainage Report
PART II EROSION CONTROL REPORT
SECTION 1 -CONSTRUCTION SEQUENCE AND PROCEDURE
This proposed subdivision 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 structural/vegetation 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. (As Required)
2. Rough grade roadway and stormwater facilities.
3. Construct infiltration stormwater facilities.
4. 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.
5. Install storm drainage piping.
6. Provide catch basin inlet protection by installing filter fabric under grates of all inlets to
drainage system.
7. Landscape, sod and/or seed and mulch all disturbed areas.
8. Flush storm drainage system.
9. 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 Nisqually (73) group and have 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 filter 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.
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Buckhorn Estates, Storm Drainage Report
SECTION 3 -PERMANENT EROSION CONTROL & SITE RESTORATION
All disturbed areas will be asphalted or seeded with grass or natural vegetation.
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 County 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 (if required)
2. The Project Engineer shall inspect the erosion control facilities after every significant
rainfall event that occurs during construction.
3. 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 Drainage.
b. Catch Basins
c. Infiltration Facilities
4. 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 Thurston County'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.
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Buckhorn Estates, Storm 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.
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Buckhorn Estates, Storm Drainage Report
ATTACHMENT "A": MAINTENANCE PROGRAM
Maintenance Checklist for Conveyance Systems (Pipes and Swales)
Frequency Drainage J 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 i e.
M J Vegetation Vegetation that reduces All vegetation
free movement of water removed so water
throw h i es. flows freely.
A J Damaged Protective coating is Pipe repaired or
(rusted, bent damaged, rust is causing replaced.
or crushed) more than 50%
deterioration to any part
of i e.
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 J 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
of non-degradable Section.
materials such as glass,
plastic, metal, foam and
coated a er.
M J Sediment Accumulated sediment Swale cleaned of all
buildup that exceeds 20% of the sediment and debris
design depth. so that it matches
design.
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Buckhorn Estates, Storm 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 J Swale does Water stands in swale or A survey may be
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 (March or April preferred)
M =Monthly (see schedule)
S =After major storms
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Buckhorn Estates, Storm 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. J 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 J 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 J Frame not sitting flush Frame is sitting flush
on top slab, i.e., on top slab.
separation of more than
3/a" of the frame from the
to slab.
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Buckhorn Estates, Storm Drainage Report
A J 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. J 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
stud e noted.
M.S. J 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.
[f 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
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Buckhorn Estates, Storm Drainage Report
ATTACHMENT "A": MAINTENANCE PROGRAM
Maintenance Checklist for Grounds (Landscaping)
Frequency Drainage 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 Safety hazard Any presence of poison No poisonous
ivy or other poisonous vegetation or insect
vegetation or insect nests present in
nests. landsca ed area.
M.S. 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
a er.
M 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 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.
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Buckhorn Estates, Storm Drainage Report
A Trees and 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 Trees or shrubs which Place stakes and
are not adequately rubber-coated ties
supported or are around young
leaning over, causing trees/shrubs for
ex osure 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 storms
Page 15
Buckhorn Estates, Storm Drainage Report
ATTACHMENT "A" : MAINTENANCE PROGRAM
Maintenance Checklist for Ponds
Frequency Drainage Problem Conditions to Check Conditions That
System For Should Exist
Feature
M,S General 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 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 Cit .
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.
Page 16
Buckhorn Estates, Storm Drainage Report
M 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
lant s ecies.
M 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 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 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.
Page 17
Buckhorn Estates, Storm Drainage Report
M Side slopes 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 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 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 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 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 majoc storms
Page 18
Buckhorn Estates, Storm 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 the Appendix of this document.
SECTION 3 -VEGETATION MANAGEMENT PLAN
All disturbed pervious areas within the site will be seeded to provide erosion control and 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.
Page 19
THURSTON 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) ..............:
Name of Road or Street to Access Facility :..................... .
Hearings Examiner Case Number :........................... .
Development Rev. Project No.Bldg. Permit No .:................ .
Parcel Numbers :.......................................... .
See Part 6
1000 85`x' Ave SE
N/A
Not Assigned
12714110400
To be completed by Utility Staff:
Utility Facility Number
Project Number (num)
Parcel Number Status: (num, lch)
0, Known; 1, Public; 2 Unknown;
3, Unassigned
Basin and Subbasin: (num, 6ch)
(2ch for basin, 2ch for subbasin, 2ch future
Responsible jurisdiction: (alpha, 1ch)
Part 1 - Proiect Name and Proponent
Project Name ................................
Project Owner ...............................
Project Contact ..............................
Address ...................................
Phone .....................................
Project Proponent: (if different) ................. .
Address ....................................
Phone .....................................
Project Engineer ............................ .
Firm .......................................
Airborne Properties, Maintenance Facility
Brian Reynolds
Brian Reynolds
7822 Highway 99 SE
(360)754-7200
Same
Same
Same
Karl Lundberg PE
Bullseye Design Group, LLC
Part 2 -Project Location
Section(s) 14
Township 17 N
Range 2 W, Willamette Meridian
Part 3 - Tyke of Permit Application
Type of permit (e.g., Commercial Bldg.): Commercial Building
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 Proiect Description
What stream basin is this project in (e.g., Percival, Woodland):.... Deschutes
Project Size, acres ...................................... 9.85 ac
Zoning ............................................... Ind
On-site:
Residential Subdivision:
Number of Lots :.................................. N/A
Lot size (average), acres :.......................... N/A
Building Permit /Commercial :......................... .
Building Footprint, acres :.......................... 1.102
Concrete Paving, acres ::....................... 7.400
Gravel Surface, acres ::....................... 0.000
Lattice Block Paving, acres :.:....................... 0.000
Public Roads (including gravel shoulder), acres:........... 0.000
Private Roads (including gravel shoulder), acres :.......... 0.000
On-site Impervious Surface Total, acres :................. 8.502
Part 5 -Pre-Developed Project Site Characteristics
Stream through site, y/n: ................................... No
Name: ............................. ..... n/a
DNR Type: ...................................n/a
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
Part 6 -Facility Description -Infiltration Pond
Total Area Tributary to Facility Including Off-site (acres):........ 8.745 ac
Total On-site Area Tributary to Facility (acres) :................ 8.745 ac
Design Impervious Area Tributary to Facility (acres) :............ 7.400 ac
Design Landscaped Area Tributary to Facility (acres):........... 1.345 ac
Design Total Tributary Area to Facility (acres) :................ 8.745 ac
Enter a one (1) for the type of facility: ) :..................... .
Wet pond detention ................................. .
Wet pond water surface volume, cf ................... .
Dry pond detention ................................ .
Underground detention ............................. .
Infiltration pond ................. ................... 1
Dry well infiltration ...................................
Coalescing plate separator ............................
Centrifuge separator ............................... .
Biofilter ...........................................
Other ..............................
Outlet type (Enter a one (1) for each type present)
Filter .............................................
Oil water separator ................................. .
Single orifice ...................................... .
Multiple orifice ..................................... .
Weir .............................................
Spillway .......................................... 1
Pump(s) ..........................................
Other .............................................
Part 7 -Release to Groundwater
Design Percolation Rate to Groundwater (if applicable) ............... 20 inch hour
Part 8 -Release to Surface Water N/A
Part 6 -Facility Description -Wet Pond
Total Area Tributary to Facility Including Off-site (acres):........ 8.745 ac
Total On-site Area Tributary to Facility (acres) :................ 8.745 ac
Design Impervious Area Tributary to Facility (acres) :............ 7.400ac
Design Landscaped Area Tributary to Facility (acres):........... 1.345 ac
Design Total Tributary Area to Facility (acres) :................ 8.745 ac
Enter a one (1) for the type of facility: ) :..................... .
Wet pond detention ................................. .
Wet pond water surface volume, cf ........... ......... 1
Dry pond detention .................................
Underground detention ............................. .
Infiltration pond ................. .................. .
Dry well infiltration ...................................
Coalescing plate separator ............................
Centrifuge separator ............................... .
Biofilter ...........................................
Other ..............................
Outlet type (Enter a one (1) for each type present)
Filter .............................................
Oil water separator ................................. .
Single orifice ...................................... .
Multiple orifice ..................................... .
Weir .............................................
Spillway .......................................... 1
Pump(s) ..........................................
Other .............................................
Part 7 -Release to Groundwater
Design Percolation Rate to Groundwater (if applicable) ............... N/A
Part 8 -Release to Surface Water N/A
Appendix I
Vicinity Map
Appendix II
Drainage Plan
Basin Plan
Appendix III
Facility Summary Form
Appendix IV
Commercial Maintenance Agreement
Appendix V
Soils Report