00-8271 Preliminary Drainage Design
. J '-"...: A..t:'
John Knowles & Associates, Inc.
PO. Box 1328
Puyallup, WA 98371-0197
(253) 539-1400
FAX 539-1500
jkacivil@nwrain.com
December 14,2000
Tim Peterson
City of Yelm Public Works
PO Box479
Yelm, WA 98597
Re TimberTec Project at Brizard Property, Rhoton Road S.E.
Preliminary Drainage Design
JKA Project #0047
Dear Tim
John S. Walter of TimberTec is proposing renovation of, and improvements to, a portion of the Brizard
property on Rhoton Road. TimberTec is interested mainly in the north-northeast portion of the
property(proposed as Lot #1 of the forthcoming short plat), that includes the existing metal building. In
conjunction with the Site Plan Review application, we have prepared this drainage letter report to meet
checklist item number ten Please consider this an abbreviated version of the future "Final" Drainage
Report for the project.
PART I - PROJECT DESCRIPTION
Section 1 - Proposed Project Description
The approximate 2.6-acre site is located in the City of Yelm, northeast of Yelm Avenue and Hwy 507
intersection The site is located in the northwesfquarter of Section 19, Township 17, Range 2E, W M.
Access to the site is via Hwy 507 to Rhoton Road. A vicinity map is included on the Preliminary Site Plan
The site is currently vacant, but past uses include commercial and manufacturing processes that resulted
in the creation of significant impervious surfaces, such as asphalt paving, concrete surfaces, and metal
roofs; these impervious surfaces still exist.
Current zoning is industrial. Building setback requirements for industrial zoning include a front setback of
15 feet, side setback of 15 feet, and a rear setback of 15 feet.
The proposal is to subdivide the property via the short plat process into three separate tax parcels. The
most north-northeasterly parcel created would be purchased by TimberTec. TimberTec proposes to
modify and enclose the existing metal building and improve the most westerly 3,000 square feet for their
vehicle maintenance purposes. TimberTec has the need for outdoor storage and interior maintenance of
logging equipment, as their business is commercial logging.
The balance of the building would be improved as needed through the building permit process, with
potential future uses such as RV storage, general vehicle and material storage, warehousing, etc. The
building may also be expanded in the future. The type of future tenant and the magnitude of the building
expansion will be driven by the market.
The site access off Rhoton Road will be improved with the construction of at least one commercial
driveway, sized to allow for ingress and egress of large trucks and trailers. It is likely the commercial
driveway will be aligned so as to serve all three lots of the short plat; covenants and easements regarding
parking, sharing of the access, sharing of the utilities, etc. will be prepared to benefit all three lots.
Civil Engineering
Project Management
Construction Management
" r V
Tim Peterson
December 14,2000
Page 2
The proponents understand that there is a requirement for the half-street improvements to Rhoton Road,
including curb, gutter, sidewalk, street widening, planter strip, and street trees. Their preference is to sign
an RID No-Protest Waiver deferring construction and financial participation for frontage improvements to
the future.
The project will require improvements to existing fire and domestic water service. These improvements
will be designed and constructed in conformance with Yelm Development Guidelines and City fire
protection requirements. The proponents understand that a reclaimed water source is available to the
project; however, at this point, no plan for extending the offsite reclaimed water line into the site is
proposed.
The project will be served by the City STEP system that currently exists on the east side of Rhoton Road.
Extension of the system into the site will be undertaken during final design.
PROPOSED STORMWA TER SYSTEM
, " ." . '.' I ',I I Development Coverage Summary I' . . I . i ,
, ..' ,Area Tribotary to IProposed Retention and Treatment Facility for Lot #1" .'
Description AcreaQe (Post-Dev )
Asohalt and asohalt/concrete mix oavement 1 86
Roof area 0.53
Total Onsite Impervious (lot #1) 2.39
Pervious 0.51
Total 2.90
The concept for storm drainage on the TimberTec lot is to collect runoff from areas subject to vehicular
traffic and direct it to a wetpond. Discharge from the wetpond will be to an infiltration basin Roof runoff
would be tightlined directly to the infiltration basin, bypassing the stormwater treatment facility Please
refer to the "Preliminary Site Plan."
Stormwater Collection - The majority of runoff will be collected in onsite catch basins. Roof runoff will
be tightlined to the storm system. Please refer to the attached "Basin Map" for area to be served by the
collection system.
Storm water Treatment - Stormwater runoff from pervious roadway and parking areas, subject to
vehicular traffic, will be treated by an open two-cell wetpond. Additionally, all catch basins will be equipped
with silt trap TEEs to further oil/water separation and trapping of sediments within the catch basin sumps,
Storm water Storage - Ultimately, onsite roadway, onsite parking, and roof runoff will be stored in an open
infiltration pond. This open basin will allow stormwater runoff to infiltrate into the underlying soils. The
bottom of the retention pond will be set at approximate elevation 319 Pond interior slopes shall be no
steeper than 3.1 The retention pond will have the capacity to store approximately 4,240 cubic feet at a
maximum 1 OO-year water surface elevation of 321 This exceeds the reauired storage volume of 3,905
cubic feet, as proven by WaterWorks hydrology software modeling using a design infiltration rate of 15"
per hour; excerpts from the WaterWorks calculations are attached.
D f..
Tim Peterson
Decernber14,2000
Page 3
Section 2 - Existing Conditions
The site is bordered by the proposed Yelm Public Works Yard facility (currently under construction) on the
south, residential properties to the west and north, and by Rhoton Road S.E. on the east.
Site topography consists of a gradual slope from the west to the northwest corner of the site. The highest
elevation is the western portion of the site, with an approximate elevation of 330 feet; the lower portion of
the site is located in the northeast corner, at approximate elevation 322. This represents an average
slope across the site of 1 5%. There is relatively little topographic relief due to the past grading and
creation of relatively level pavement surfaces associated with industrial operations.
Vegetation outside the existing asphalt surfacing consists generally of grasses and scattered deciduous
and Douglas fir trees. At this time, there is no proposal to preserve any trees that exist on the future
TimberT ec parcel (Lot #1 )
There are no significant man made drainage features on the site. The residential subdivision adjacent to
the north includes an open infiltration basin located along the project site's north property line. The Yelm
Public Works facility drainage system of an open wetpond and infiltration basin is located just south of the
overall Brizard Company property, adjacent to Rhoton Road. Offsite runoff from the west, north, and
south sides of the site is insignificant due to the relatively well-draining Spanaway series soils
characteristic of the site.
No significant slopes exist onsite. There are no significant gullies, ravines, wetlands, or other
environmentally sensitive areas.
The site is located in an aquifer-sensitive area based on review of Thurston County Comprehensive Plan
Map M8. This project will comply with the stormwater treatment requirements of the DOE SWM Manual to
mitigate its potential impacts on the aquifer
Section 3 -Infiltration Rates Soils Report
The Soil Conservation Service (SCS) Soil Survey of Thurston County maps the onsite soils as #110 _
Spanaway Gravelly Sandy Loam, 0-3% slopes. During final design, site-specific soil tests will be
excavated by the owner and logged by JKA. Test pits excavated offsite (along the Brizard south property
line) for the Public Works Yard indicated relatively deep, well-draining, Spanaway series soils. JKA
anticipates similar soil conditions for the TimberTec site, therefore, a design infiltration rate of 15 in/hr was
used for conceptual sizing purposes.
Section 4 - Wells
The project will be served by City of Yelm water system. An offsite well exists several hundred feet
southwest of the Brizard property's southwest corner; proposed development will not adversely affect this
well, nor will it have any impact on the siting of the infiltration facility at the northwest corner of the
proposed TimberT ec parcel. The existing groundwater monitoring wells in the northwest corner of the site
will be abandoned as part of the development.
The project will be served by City of Yelm STEP sewage disposal system. If, during construction, any
onsite sewage drainfields are found, they will be abandoned in accordance with Thurston County
Environmental Services criteria.
, D V
Tim Peterson
December 14,2000
Page 4
Section 5 - Fuel Tanks
Several fuel tanks did exist on the site in the past. These tanks were determined to have leaked and
were placed on the Department of Ecology's "Hazardous Sites" list. Remediation of the site is well
documented by three AGI Technologies reports. A February 1, 2000, letter from Charles Cline(of DOE)
to Mr Cameron Appleton (Brizard Company) confirmed that, "The release of total petroleum hydrocarbons
and metals into the soil no longer poses a threat to human health or the environment. Therefore, Ecology
is issuing this determination that no further remedial action is necessary at this time "The Department
of Ecology reminds that if any other underground tanks are found, they must be abandoned and any
contamination remediated in accordance with current code and policy
Section 6 - Sub-Basin Description
Based on available topography and site visits, no significant offsite runoff is tributary to the development
portion of the site. Therefore, there is no need to oversize the proposed storm drainage facilities to
accommodate offsite runoff
Section 7 - Analysis of 100-Year Flood
The site is mapped as Flood Zone C by FEMA. FEMA defines Zone C as "areas of minimal flooding "
Section 8 - Aesthetic Considerations for Stormwater Facilities
Stormwater facilities shall be landscaped in accordance with City of Yelm requirements. The retention
pond and wetpond side slopes will be vegetated and landscaped
Section 9 - Downstream Analysis and Facility Sizing
Calculations for project conveyance, retention, and treatment systems will be provided during final design
phase of the project. For now, we have summarized our WaterWorks modeling data in Section 1 of this
report and enclosed excepts from our preliminary modeling.
All project runoff will be treated and stored onsite within the proposed stormwater system, there will be no
significant release of runoff from this site.
Section 10 - Covenants, Dedications, and Easements
Drainage facilities, including conveyance swales, wetpond, retention pond, piping, and catch basins, will
require occasional maintenance. The drainage facilities will be maintained by TimberTec and subsequent
owners of the property Site development will allow City access to the stormwater facilities for the purpose
of inspection, maintenance, water quality monitoring, and other activities as allowed by City ordinance.
I II ' V
Tim Peterson
December 14,2000
Page 5
P ART II - EROSION CONTROL REPORT
Section 1 - Construction Sequence And Procedure
Final design will include site grading and erosion control measures designed to contain silt and soil within
the project boundaries during construction until permanent erosion control is in place
Erosion/sedimentation control shall be achieved by a combination of structural/vegetative 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 may be as follows:
1 Install rock construction entrance. Use quarry spalls or rip rap with 12" minimum depth.
2. Install filter fabric fencing, as needed.
3 Use wetpond cells as temporary sedimentation basins, if necessary
4 Clear site (grubbing and rough grading)
5 During October 1st through April 30th, all disturbed areas greater than 5,000 sf that are subject to
erosion should be stabilized by one of the following: mulch, sodding, or plastic covering
6 Install underground utilities (storm, water, power, etc.)
7 Provide catch basin protection by installing filter fabric between frame and grate of all inlets to
drainage system
8 After paving is complete, install landscape, sod and/or seed, and mulch all disturbed areas.
9 Maintain all erosion control facilities until the entire site is stabilized and silt runoff ceases.
10 Designate an area for washing of equipment and concrete trucks to control the runoff and eliminate
entry into storm drainage systems.
Section 2 - Trapping Sediment
The onsite soils belong to the Spanaway soil group and have a slight erosion potential according to the
SCS. Filter fabric fencing shall be installed where appropriate, to control erosion from disturbed areas. A
stabilized construction entrance shall be installed to prevent vehicles from tracking soil away from the
disturbed areas. If sediment is tracked offsite, sediment shall, on a daily basis, be swept or shoveled from
the paved surface prior to washing down pavement.
Section 3 - Permanent Erosion Control & Site Restoration
All disturbed areas will be paved, covered with gravel surfacing, covered with a building or landscaped
with grass, shrubbery or trees per the landscaping plans, or as specified on the final development plans.
Section 4 - Geotechnical Analysis And Report
Slopes exceeding 15% do not exist onsite. Therefore, a geotechnical analysis is unnecessary from an
erosion control, grading, and drainage standpoint.
, D
Tim Peterson
December 14,2000
Page 6
Section 5 - Inspection Sequence
In addition to the normal City inspections, the Project Engineer must inspect the facilities related to
stormwater treatment, erosion control, storage and conveyance during construction. At a minimum, the
following items should be inspected at the time specified:
1 The erosion control facilities should be inspected before the start of clearing and grading to ensure the
following structures are in place:
a. Construction Entrance
b. Filter Fabric Fences (if needed)
c. Inlet Protection
2. The drainage systems will be inspected after construction of the facility, but before the project is
completed to ensure the following are in working order'
a. Retention pond and wet pond
b Catch basins.
c. Roof drains.
3 The permanent site restoration measures should be inspected after landscaping is completed.
It is the responsibility of the owner/developer to inform the engineer of the timing of the above construction
phases. A final inspection shall be performed to verify final grades, drainage construction, and all
necessary information to complete Engineer's Construction Inspection Report Form. This form must be
completed prior to final public works construction approval.
Section 6 - Control Of Pollutants Other Than Sediments
Washout from a concrete truck shall not be dumped into the storm drain, or onto soil and pavement,
which carries stormwater runoff It can be dumped into a designated area to be later back-filled or
hardened and broken up for disposal into a dumpster The owner shall designate a washdown area for
equipment and concrete trucks.
~
Tim Peterson
December 14,2000
Page 7
PART III MAINTENANCE PLAN
Section 1 - Required Maintenance
The drainage facilities will require occasional maintenance. The following general requirements are the
minimum requirements. Yearly maintenance costs can be estimated as:
TASK DESCRIPTION COST
Maintain grass within pond facility @ $50/week
x 12 weeks $600 00
Remove silt from catch basins @ $200 OO/year $200 00
Pruning/landscaping @ $200 OO/year $200.00
TOTAL $1,000.00
The required maintenance for the proposed storm drainage facilities and frequency of maintenance are as
described in the following checklists:
Section 2 - Responsible Organization
TimberTec, or its successors, shall be responsible for the operation and maintenance of all onsite
drainage facilities associated with the proposed TimberTec parcel (Lot #1)
Section 3 - Vegetation Management Plan
All disturbed pervious areas within the proposed TimberTec parcel will be landscaped to provide an
aesthetically pleasing environment.
Section 4 - Source Control
Warning signs (e g., "Dump No Waste - Drains to Groundwater") will be painted or embossed on or
adjacent to all storm drain inlets and shall be repainted periodically as necessary This shall be the
responsibility of TimberTec and/or its successors.
. ,
Tim Peterson
December 14,2000
Page 8
Maintenance Checklist for Catch Basins and Inlet$
Frequency Drainage ..J Problem Conditions to Conditions That Should
System Check For Exist
Feature
M,S General Trash, debris, Trash or debris in No trash or debris is located
and sediment front of the catch immediately in front of catch
in or on basin. basin opening is basin opening. Grate is
blocking capacity by kept clean and allows water
more than 10% to enter
M Sediment or debris No sediment or debris in the
(in the basin) that catch basin. Catch basin is
exceeds 1/3 the dug out and clean
depth from the
bottom of basin to
invert of the lowest
pipe into or out of the
basin.
M Trash or debris in Inlet and outlet pipes free of
any inlet or pipe trash or debris.
blocking more than
1/3 of its height.
M Structural Corner of frame Frame is even with curb.
damage to extends more than
frame and/or 3/4 inch past curb
top slab face into the street (if
applicable)
M Top slab has holes Top slab is free of holes
larger than 2 square and cracks.
inches or cracks
wider than 1/4 inch
(intent is to make
sure all material is
running into the
basin)
M Frame not sitting Frame is sitting flush on top
flush on top slab, slab
i.e., separation of
mor~ than 3/4 inch
of the frame from the
top slab
, '.
Tim Peterson
December 14,2000
Page 9
A Cracks in Cracks wider than Basin replaced or repaired
basin 1/2 inch and longer to design standards.
walls/bottom than 3 feet, any Contact a professional
evidence of soil engineer for evaluation.
particles entering
catch basin through
cracks, or
maintenance person
judges that structure
is unsound.
A Cracks wider than No cracks more than 1/4
1/2 inch and longer inch wide at the joint of
than 1 foot at the inlet/outlet pipe. Contact a
joint of any professional engineer for
inlet/outlet pipe or evaluation.
any evidence of soil
particles entering
catch basin through
cracks.
A Settlement/mis Basin has settled Basin replaced or repaired
-alignment more than 1 inch or to design standards.
has rotated more Contact a professional
than 2 inches out of engineer for evaluation
alignment.
M,S Fire hazard or Presence of No color, odor, or sludge.
other pollution chemicals such as Basin is dug out and clean.
natural gas, oil, and
gasoline. Obnoxious
color, odor, or
sludge noted.
M,S 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 a professional engineer
Comments:
KEY
A = Annual (March or April preferred)
M = Monthly (see schedule)
S = After major storms (use 1-inch in 24 hours as guideline)
. ,
Tim Peterson
December 14,2000
Page 10
Maintenance Checklist for Ponds
Frequency Drainage ..J Problem Conditions to Conditions That
System Check For Should Exist
Feature
M,S General Trash & Dumping of yard Remove trash and debris
debris buildup wastes such as and dispose as
in pond grass clippings prescribed by the
and branches County
into basin.
Unsightly
accumulation of
nondegradable
materials such
as glass, plastic,
metal, foam, and
coated paper
M,S Trash rack Bar screen over Replace screen.
plugged or outlet more than Remove trash and debris
missing. 25% covered by and dispose as
debris or prescribed by the
missing. County
M Poisonous Any poisonous Remove poisonous
vegetation vegetation which vegetation Do not spray
may constitute a chemicals on vegetation
hazard to the without obtaining
public. guidance from the
Examples of Cooperative Extension
poisonous Service and approval
vegetation from County
include. tansy
ragwort, poison
oak, stinging
nettles,
devilsclub
M,S Fire hazard or Presence of Find sources of pollution
pollution chemicals such and eliminate them
as natural gas, Water is free from
oil, gasoline, noticeable color, odor, or
obnoxious color, contamination.
odor, or sludge
noted.
. ,
Tim Peterson
December 14,2000
Page 11
M Vegetation For grassy For grassy ponds,
not growing ponds, grass selectively thatch,
or is cover is sparse aerate, and reseed
overgrown and weedy or is ponds. Grass cutting
overgrown. For unnecessary uriless
wetland ponds, dictated by aesthetics.
plants are For wetland ponds,
sparse or hand-plant nursery-
invasive species grown wetland plants in
are present. bare areas. Contact the
Cooperative Extension
Service for direction on
invasive species such as
purple loosestrife and
reed canary grass. Pond
~ bottoms should have
uniform coverage of
designed plant species.
M Rodent holes Any evidence of Rodents destroyed and
rodent holes if dam or berm repaired
facility is acting Contact the Tacoma-
as a dam or Pierce County Health
berm, or any Department for
evidence of guidance.
water piping
through dam or
berm via rodent
holes.
M Insects Insects such as Insects destroyed or
. wasps and removed from site.
hornets interfere Contact Cooperative
with Extension Service for
maintenance guidance.
activities or
when
mosquitoes
become a
nuisance.
Tim Peterson
December 14,2000
Page 12
A Tree growth Tree growth Trees do not hinder
does not allow maintenance activities.
maintenance Selectively cultivate trees
access or such as alders for
interferes with firewood.
maintenance
activity (e.g.,
slope mowing,
silt removal, or
equipment
movements) If
trees are not
interfering with
access, leave
trees alone.
M Side slopes Erosion on Check around Find causes of erosion
of pond berms or at inlets and outlets and eliminate them
entrance or for signs of Then slopes should be
exit erosion. Check stabilized by using
berms for signs appropriate erosion
of sliding or control measures(s),
settling Action e.g., rock reinforcement,
is needed where planting of grass,
eroded damage compaction
over 2 inches
deep and where
there is potential
for continued
erosion.
M Storage Sediment Accumulated Sediment cleaned out to
area build-up in sediment that designed pond shape
pond. exceeds 10% of and depth, pond
the designed reseeded if necessary to
pond depth control erosion.
Buried or
partially buried
outlet structure
probably
indicates
significant
sediment
deposits.
A Pond dikes Settlements Any part of dike Dike should be built back
which has to the design elevation
settled 4 inches
lower than the
design elevation.
Tim Peterson
December 14,2000
Page 13
A Emergency Rock missing Only one layer of Replace rocks to design
overflow/spill rock exists standards.
-way above native soil
in area 5 sf or
larger, or any
exposure of
native soil.
One time Emergency Overflow Side of pond has Contact the County for
overflow/spill missing no area with guidance.
-way large rocks 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
S = After major storms
Tim Peterson
December 14,2000
Page 14
Maintenance Checklist for Infiltration Systems
Frequency Drainage v Problem Conditions to Conditions That Should
System Check For Exist
Feature
M,S General Trash & See Maintenance See Maintenance Checklist
debris Checklist for for Ponds.
buildup in Ponds.
pond
M Poisonous See Maintenance See Maintenance Checklist
vegetation Checklist for for Ponds.
Ponds.
M,S Fire hazard See Maintenance See Maintenance Checklist
or pollution Checklist for for Ponds.
Ponds.
M Vegetation See Maintenance See Maintenance Checklist
not growing Checklist for for Ponds.
or is Ponds.
- overgrown
M Rodent See Maintenance See Maintenance Checklist
holes Checklist for for Ponds.
Ponds.
M Insects See Maintenance See Maintenance Checklist
Checklist for for Ponds.
Ponds.
A Storage Sediment A soil texture test Sediment is removed and/or
area buildup in indicates facility is facility is cleaned so that
system not working at its infiltration system works
designed according to design. A
capabilities or was sediment trapping area is
incorrectly installed to reduce sediment
designed. transport into infiltration area.
Tim Peterson
December 14,2000
Page 15
A Storage A soil texture test Additional volume is added
area drains indicates facility is through excavation to
slowly (more not working at its provide needed storage Soil
than 40 designed is aerated and rototilled to
hours) or capabilities or was improve drainage. Contact
overflows incorrectly the County for information on
designed. its requirements regarding
excavation.
M Sediment Any sediment and Clean out sump to design
trapping debris filling area depth
area of 10% of depth
from sump bottom
to bottom of outlet
pipe or obstructing
flow into the
connector pipe.
One time Sediment Stormwater enters Add a trapping area by
trapping infiltration area constructing a sump for
area not directly without settling of solids. Segregate
present treatment. settling area from rest of
facility Contact the County
for guidance.
M Rock filters Sediment By visual Replace gravel in rock filter
and debris inspection little or
no water flows
through filter
during heavy rain
storms.
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
S = After major storms
Tim Peterson
December 14,2000
Page 16
Maintenance Checklist for Fencing/Shrubbery Screen/Other Landscaping
Frequency Drainage ..j Problem Conditions to Conditions That
System Check For Should Exist
Feature
M General Missing or Any defect in the Fence is mended or
broken fence or screen shrubs replaced to form a
parts/dead that permits easy solid barrier to entry
shrubbery entry to a facility
M,S Erosion Erosion has Replace soil under fence
resulted in an so that no opening
opening under a exceeds 4 inches in
fence that allows height.
entry by people or
pets.
M Unruly Shrubbery is Shrubbery is trimmed and
vegetation growing out of weeded to provide
control or is appealing aesthetics. Do
infested with not use chemicals to
weeds. control weeds.
A Wire fences Damaged parts Posts out of plumb Post plumb to within 1-1/2
more than 6" inches of plumb
A Top rails bent Top rail free ofbends
more than 6 greater than 1 inch.
inches.
A Any part of fence Fence is aligned and
(including posts, meets design standards.
top rails, and
fabric) more than
1 foot out of
design alignment.
A Missing or loose Tension wire in place and
tension wire. holding fabric.
A Missing or loose Barbed wire in place with
barbed wire that is less than 3/4 sag between
sagging more than posts.
2-1/2" between
posts.
A Extension arm Extension arm in place
missing, broken, with no bends larger than
or bent out of 3/4 inch.
shape more than
1-1/2 inches.
Tim Peterson
December 14, 2000
Page 17
A Deteriorated Part or parts that Structurally adequate
paint or have a rusting or posts or parts with a
protective scaling condition uniform protective coating.
coating. that has affected
structural
adequacy
M Openings in Openings in fabric No openings in fabric.
fabric are such that an
a-inch diameter
ball could fit
I through.
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
S = After major storms
Tim Peterson
December 14,2000
Page 18
Maintenance Checklist for Conveyance Systems (Pipes, Ditches, and Swales)
Frequency Drainage ..j Problem Conditions to Conditions That Should
System Check For Exist
Feature
M,S Pipes Sediment & Accumulated Pipe cleaned of all sediment
debris sediment that and debris.
exceeds 20% of
the diameter of the
pipe.
M Vegetation Vegetation that All vegetation removed so
reduces free water flows freely through
movement of pipes.
water through
pipes.
A Damaged Protective coating Pipe repaired or replaced.
(rusted, bent is damaged, rust is
or crushed) causing more than
50% deterioration
to any part of pipe.
M Any dent that Pipe repaired or replaced
significantly
impedes flow (Le.,
decreases the
cross section area
of pipe by more
then 20%)
M Pipe has major Pipe repaired or replaced
cracks or tears
allowing
groundwater
leakage.
M,S Open Trash & Dumping of yard Remove trash and debris
ditches debris wastes such as and dispose as prescribed by
grass clippings the County
and branches into
basin. Unsightly
accumulation of
non-degradable
materials such as
glass, plastic,
metal, foam and
coated paper
Tim Peterson
December 14,2000
Page 19
M Sediment Accumulated Ditch cleaned of all sediment
buildup sediment that and debris so that it matches
exceeds 20% of design.
the design depth.
A Vegetation Vegetation (e.g., Water flows freely through
weedy shrubs or ditches. Grassy vegetation
saplings) that shall be left alone.
reduces free
movements of
water through
ditches.
M Erosion See Ponds See Ponds Checklist.
damage to Checklist.
slopes
A Rock lining Maintenance ' Replace rocks to design
out of place person can see standard.
or missing (if native soil beneath
applicable) the rock lining.
Varies Catch See Catch Basins See Catch Basins Checklist.
basins Checklist.
M,S Swales Trash & See above for See above for Ditches
debris Ditches.
M Sediment See above for Vegetation may need to be
buildup Ditches. replanted after cleaning.
M Vegetation Grass cover is Aerate soils and reseed and
not growing sparse and seedy mulch bare areas. Maintain
or or areas are grass height at a minimum of
overgrown overgrown with 6 inches for best stormwater
woody vegetation treatment. Remove woody
growth, recontour, and
reseed as necessary
M,S Erosion See Ponds See Ponds Checklist.
damage to Checklist.
slopes
Tim Peterson
December 14,2000
Page 20
M Conversion Swale has been If possible, speak with
by filled in or blocked homeowner and request that
homeowner by shed, woodpile. swale area be restored.
to shrubbery, etc. Contact the County to report
incompatible problem if not rectified
use voluntarily
A Swale does Water stands in A survey may be needed to
not drain swale or flow check grades. Grades need
velocity is very to be in 1-5% range if
slow Stagnation possible. If grade is less
occurs. 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
S = After major storms
. '
. .
Tim Peterson
December 14, 2000
Page 21
Maintenance Checklist for Grounds (Landscaping)
Frequency Drainage .J Problem Conditions to Conditions That Should
System Check For Exist
Feature
M General Weeds (non- Weeds growing in Weeds present in less than
poisonous) more than 20% of 5% of the landscaped area.
the landscaped
area (trees and
shrubs only)
M Insect hazard Any presence of No poisonous vegetation or
poison ivy or other insect nests present in
poisonous landscaped area.
vegetation or insect
nests.
M,S Trash or litter See Ponds See Ponds Checklist.
Checklist.
M,S Erosion of Noticeable rills are Causes of erosion are
ground seen in landscaped identified and steps taken to
surface areas. slow down/spread out the
water Eroded areas are
filled, contoured, and
seeded.
A Trees Damage Limbs or parts of Trim trees/shrubs to restore
and trees or shrubs that shape. Replace
shrubs are split or broken trees/shrubs with severe
which affect more damage.
than 25% of the
total foliage of the
tree or shrub
M Trees or shrubs Replant tree, inspection for
that have been injury to stem or roots.
blown down or Replace if severely
knocked over damaged.
A Trees or shrubs Place stakes and rubber-
which are not coated ties around young
adequately trees/shrubs for support.
supported or are
leaning over,
causing exposure
of the roots.
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; S = After major storms
. .
Tim Peterson
December 14,2000
Page 22
Maintenance Checklist for Access Roads/Easements
Frequency Drainage .J Problem Conditions to Conditions That
System Check For Should Exist
Feature
One Time General No access If ponds or other Determine whether an
road exists drainage system easement to drainage
features needing feature exists. If yes,
maintenance by obtain County permits
motorized and construct gravel (or
equipment are equal) access road. If
present, either not, report lack of
an access road easement to the
or access from municipality
public street~ is
required.
M Blocked Debris which Roadway free of debris
roadway could damage which could damage
vehicle tires tires.
(glass or metal)
A Any obstructions Roadway overhead clear
which reduce to 14 feet high
clearance above
road surface to
less than 14
feet.
A Any obstructions Obstruction removed to
restricting the allow at least a 15-foot
access to less wide access.
than 15 feet
width.
A,S Road Settlement, When any Road surface uniformly
surface potholes, surface smooth wino evidence of
mush spots, irregularity settlement, potholes,
ruts. exceeds 6" in mush spots or ruts.
depth and 6 sf in Occasional application of
area. In general, additional gravel or pitrun
any surface rock needed.
defect which,
hinders or
prevents
maintenance
access.
<l
..
~
Tim Peterson
December 14, 2000
Page 23
M Vegetation in Woody growth Remove woody growth
road surface that could block @ early stage to prevent
vehicular vehicular blockage. Cut
access. back weeds if they begin
Excessive weed to encroach on road
cover surface
M,S Shoulders Erosion Erosion within 1 Shoulder free of erosion
and ditches damage foot of the and matching the
roadway more surrounding road.
than 8" wide and
6" deep
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
S = After major storms
This letter represents the project's preliminary drainage design requirement pursuant to checklist item
number ten of the Site Plan Review application form. Please call us if you have any questions or require
additional information regarding the project's proposed storm drainage system.
Sincerely,
f1/~
JOHN KNOWLES & ASSOCIATES, INC.
John Knowles, P E.
President
enc. (Basin Map and WaterWorks calc summary)
cc: John S Walter
(c:\winwordUEKfiles\0047N 16P,/tr)
.GRAPHIC SCALE
60 0 30 60 120
r-.-~__~IJ
( IN FEET )
1 inch \= 60 y.
\
\
\
JKA
JOHN KNOWLES & ASSOCIATES. INC.
Civil Engineering
Project Management
Construction Management
Q .
I
\Jtl
~
~1t:J
~~ ~I
E<. ""GlE FAMILY /' II \\
RESIOENTlAL I~ ,I I
(PI\RCEL #21-0204) }~I j
oco .f' ~
(
I
I I I
f l'
~~11 I i
---J I 'f I
\ J
\ \ I
D :JINCLE PI\MIL) I I
RESIDENTIAL I
(PARCEL #21-03041 I I
PO Box 1328
Puyailup, WA 98371-0197
""
VERTICAL DA TUM
CITY OF YELM SEWER DA TUM
BASIS OF BEARINGS CITY OF YELM SHORT PLA T NO. SS8036
BENCHMARK. EXISTING RAILROAD SPIKE IN BASE OF POWERPOLE
ELEVATION =326.06
ELEVATION IS REFERENCED FROM. AT-5 USED FOR
CITY OF YELM SEWER PROJECT '~1l.T-5 IS A RR SPIKE
IN CL OF RHOTON RD. 400' N OF IN:r NP RD.
ELEVA TION = 328.89 "-,
,
~:';. c,~,~~[: ,~":",,,., ~c'f~~03~~~~~1
D SINGLE FI\M1L
RCWENTlI\L SUBDIVISION
/
\ /'
\\ ,1"
I /-"X
V ~
~-I
,~--~perv;ou~, Te
tLO .3 .,
\
J (1.90 f.C) j
I..... \ BASIN BOUNDARY
1 \ _ ';
\
\,
6~HAINUNK S[CIJi'?lfr FENCE
TO THE" NORTH. METAL POST
- WI BARBED ~WRE" FENCE
TO [SOUTH
)
\~-
~\
\
\
\
\
j
q
\ /
--\---1-
~ - L ---=- ----\. _ ----r _
' co _ \ I
~ ~ --\- - - -'-
\~-~--. \ I
-----...... ~~- \ \ I
~~. \.; \
\ -........-........ '1-. \
'\ r"~, '
"'---........ \
I '-,,"~~'
\ , ,
(.D4RCEL #<:\-04031 I I \ -................~."'._....,
\ I _
I
I
!
i
.--. ---
---
N 8-<r2r'48" W -..rh
- - Jon, - IT.. _ _
\
I
I
~R~.....
- - -I) \ ,",.j ..,.v" /
"r \ I
~ \ $
l'll~ \ /'
010 \
"<: I ,!:,
m /
........"'.~ I \t. \ (
---------.-~-,,-~-~ ~Jl~ \ \, '"
~'----" ~" "
--- '--. ,
---....: ___ \".'8 ___ ,
['{ elT( OF yELM .~ ----:~ _____. " t /'" ""
PUBLIC WORKS YARD I ~~_ 10 ~-- --__ '-- ---l--~ "
(PI\RCEL#lJ-CI404) BASIN MAP I \~~~~-- ]r
I \ <95.., -.._~ _ ~ ""\ ~
I \ ........~-~.
. \ ' ~, ----
I \ '.,.,
\ \ 1\ -'---l
\ \ ,
\
(253) 539-1400
FAX 539-1500
LOT#1
EXPIRES 11/10/2002
q ,,, "II
12/12/00
3:48:42 pm
JKA JOB #0047
Shareware Release
TIMBERTEC
1
page
=====================================================================
BASIN SUMMARY
BASIN ID: DEV100
SBUH METHODOLOGY
TOTAL AREA.......:
RAINFALL TyPE....:
PRECIPITATION....:
TIME INTERVAL....:
NAME: DEVELOPED 100YR-24HR
E;;;;rE Alrl DN
Lo r.J:t; /
2.90 Acres BASEFLOWS: 0.00 cfs
TYPE1A PERV IMP
4.10 inches AREA. . : 0.51 Acres 2.39 Acres
10.00 min CN.... : 78.00 / 98.00
TC. . . . : 22.18 min /' 5.00 min
ABSTRACTION COEFF: 0.20
TcReach - Sheet L: 129.00 ns:0.2400 p2yr: 2.00 s:0.0240
TcReach - Shallow L: 37.00 ks:27.00 s:0.0100
TcReach - Channel L: 245.00 kc:42.00 s:0.0050
impTcReach - Sheet L: 232.00 ns:0.0110 p2yr: 2.00 s:0.0160
impTcReach - Shallow L: 37.00 ks:27.00 s:0.0100
impTcReach - Channel L: 245.00 kc:42.00 s:0.0050
PEAK RATE: 2.21 cfs VOL: 0.85 Ac-ft TIME:
BASIN ID: DEV6
SBUH METHODOLOGY
TOTAL AREA.......
RAINFALL TyPE....:
PRECIPITATION.. ..:
TIME INTERVAL....:
NAME: DEVELOPED 6MONTH
480 min
VVet' PQlV 0
L- DI J:t: I
0.00 cfs
PERV
0.51 Acres
78.00
22.18 min
2.90 Acres
TYPE1A
1.28 inches
10.00 min
BASEFLOWS:
AREA. . :
CN....:
TC. . . . :
IMP
2.39 Acres
98.00
5.00 min
ABSTRACTION COEFF: 0.20
TcReach - Sheet L: 129.00 ns:0.2400 p2yr: 2.00 s:0.0240
TcReach - Shallow L: 37.00 ks:27.00 s:0.0100
TcReach - Channel L: 245.00 kc:42.00 s:0.0050
impTcReach - Sheet L: 232.00 ns:0.0110 p2yr: 2.00 s:0.0160
impTcReach - Shallow L: 37.00 ks:27 00 s:0.0100
impTcReach - Channel L: 245.00 kc:42.00 s:0.0050
PEAK RATE: 0.59 cfs VOL: TIME. 480 min
WE-rI~[.7/'J D VtJLU//J ~
~c=QU/ Ct:::'HlENT
00 f1'
12/12/00
3:48:42 pm
Shareware Release
TIMBERTEC
page
2
JKA JOB #0047
---------------------------------------------------------------------
---------------------------------------------------------------------
STAGE STORAGE TABLE
CUSTOM STORAGE
Description: INFIL.
ID No. POND
POND
J<EIE Nrl 0 Ai
Lor It: /
POND
STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE---->
(ft) ---cf--- nAc-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft-
fiND ========================================================================================================
/301fom ~ 319 00 0 0000 0 0000 319 60 860 40 0 0198 320 20 1995 0 0458 320 80 3680 0 0845
319 10 143 40 0 0033 319 70 1004 0 0230 320 30 2276 0 0523 320 90 3960 0 0909
319 20 286 80 0 0066 319 80 1147 0 0263 320 40 2557 0 0587 321 00 4241 0 0974
319 30 430 20 0 0099 319 90 1291 0 0296 320 50 2838 0 0651
319 40 573 60 0 0132 320 00 1434 0 0329 320 60 3118 0 0716
319 50 717 00 0 0165 320 10 1715 0 0394 320 70 3399 0 0780
/~() y't::. WA-T~ 5uJifA-CG
EL€V
<l <1' IT
12/12/00
3:48:42 pm
Shareware Release
TIMBERTEC
page
3
JKA JOB #0047
---------------------------------------------------------------------
---------------------------------------------------------------------
STAGE DISCHARGE TABLE
DISCHARGE LIST ID No. POND
D~scription: INFILTRATION POND
~-rENTI CJ Ai PuAJ C)
Lor t:C I
STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE--->
(ft) ---cfs-- ------- (ft) ---cfs-- ------- (ft) ---cfs-- ------- (ft) ---cfs-- -------
--------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------
319 00 0 4980 319 60 0 6396 320 20 0 7832 320 80 0 9308
319 10 0 5216 319 70 0 6632 320 30 0 8078 320 90 0 9554
319 20 0 5452 319 80 0 6868 320 40 0 8324 321 00 0 9800
319 30 0 5688 319 90 0 7104 320 50 0 8570
319 40 0 5924 320 00 0 7340 320 60 0 8816
319 50 0 6160 320 10 0 7586 320 70 0 9062
(j QI ~; "0"
12/12/00
3:48:44 pm
Shareware Release
TIMBERTEC
page
4
JKA JOB #0047
=====================================================================
LEVEL POOL TABLE SUMMARY
MATCH INFLOW -STO- -DIS- <-PEAK->
OUTFLOW STORAGE
<--------DESCRIPTION---------> (cfs) (cfs) --id- --id- <-STAGE> id (cfs) VOL (cf)
=====================================================================================
100YR 24HR
o 00
o 95 3904 58 cf
/lJrf X ~ / aJ Y R... W A-IER-
,-:>UIf.. FACe ELl=.-v'