bld20090316-Tiegs-2.pdf
City of Edmonds
TH
121 5 AVENUE NORTH • EDMONDS, WA 98020 • (425) 771-0220 FAX(425) 771-0221
Website: www.ci.edmonds.wa.us
PUBLIC WORKS DEPARTMENT
Engineering Division
Plan Review Corrections
Plan Check :Date:
#2009-0316 August 18, 2009
Project Name/Address:
Tiegs 16911 Talbot Rd
Contact Person/Address/Fax:
Phil & Diana Tiegs ptiegs@yahoo.com
JoAnne ZulaufDivision:Engineering
Reviewer:
During review of the subject submittal, it was found that the following information, corrections,
or clarifications would need to be addressed. Our handouts can be found online at the City of
Edmonds web site www.ci.edmonds.wa.us under City Government/Development
Services/Engineering Division.
Site Plan:
1.8/6/09 No changes made. Site plan is very difficult to read. Since demo has been issued please remove
the layer showing the existing home and other existing features that will be removed for clarity.
2.8/6/09 Is this square footage included in existing impervious surface calculations? If two existing shed
buildings will remain, add to site plan.
3.8/6/09 Done.
4.8/6/09 Done.
5.8/6/09 Done.
6.8/6/09 Done.
7.8/6/09 TESC plan not consistant with other plans. Nelson Geotechnical Associates (NGA) report
indicates that construction stockpiles shall be placed no closer than 30ft from the top of slope. Show
intended location of stockpile materials on site plan.
8.8/6/09 Defer to Building Department.
9.The proposed development impacts the rockery therefore the rockery must be in compliance with
Edmonds Community Development Code. Rockery must be removed from the right of way and set
back a distance from the right of way equal to its height. Please check with Planning to see if there are
any other requirements.
DATE MAILED/FAXED 8/18/2009 PAGE ____ OF ___
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Drainage/Detention:
10.08/11/09 See Stormwater Engineer Comments below. Site plan shows detention system installed
through the existing rockery. Please show where rockery will be removed, where detention will be
located and how grades will be handled around that area. Also submit an evaluation from NGA (as
recommended on pg 6 of report) regarding the placement of the detention system at the slope area and
the removal of a portion of the rockery.
11.8/6/09 Okay.
12.08/11/09 See Stormwater Engineer Comments below.Please resubmit detention system calculations. A
quick measurement of roofline of house and driveway on site plan puts the impervious surface over
5000sf. The Detention handout worksheet no longer is applicable if impervious surface is equal to or
greater than 5000sf. A detention system designed by a Washington State licensed engineer is required.
Please submit drainage report and system calculations.
13.8/6/09 Show exact proposed location of new 12” cb. Will trough drain be used to catch water? I see a
berm added between new driveway edge and old driveway edge. Please clarify plan for this area. Please
provide on site plan proposed rim and invert elevations for the detention catch basins.
14.8/6/09 See #13. Show on site plan how driveway surface water will be captured into the detention
system both at area near garage and at the base of driveway. NGA report indicates that all drainage
should be directed away from the slopes therefore must be “caught” and directed to detention. Include
on site plan all rim and invert elevations for all new drains/catch basins.
15.08/06/09 Joining of footing drains and outflow from detention/retention/raingarden must be on private
property. Move “y” inside of property line. Site plan submitted shows footing drains and tightline
connecting to storm system in the right of way and bypassing the detention system. Tightline must go
through detention system. Footing drains can be directly connected to the outfall catch basin. Show
footing drain and tightline from connection to house to connection to drainage system. Per NGA report
footing drains must be embedded at least 3 ft into medium dense or better native soil. Please indicate
the depth of footing drain on site plan. All connections must be within private property.
16.08/11/09 See Stormwater Engineer comments below. A bioswale is shown on the site plan. Please
clarify the runoff that is intended to be caught by the bioswale and show where the water collected in the
bioswale will discharge. Submit detail showing construction of proposed bioswale.
Utilities:
17.8/6/09 Done.
18.8/6/09 Done.
19.08/11/09 Still need.If utility locations conflict with placement of detention system or rain garden
system, please show how separation requirements will be met.
20.8/6/09 Done.
21.8/6/09 Done.
22.8/6/09 Done.
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23.8/6/09 Done.
Erosion Control:
24.Erosion Control:
a)8/6/09 Done.
b)8/6/09 Done.
c)8/6/09 Done.
d)08/11/09 Still need.Show specific measures to be taken in area where detention or
rain garden will be placed and rockery removed.
e)8/6/09 Done.
f)8/6/09 Done.
Stormwater Engineer Comments:
I have reviewed the following documents:
Supplemental Rain Garden Infiltration Letter, Tiegs Residence, 16911 Talbot Road, Edmonds, Washington For
Mr. Phil Tiegs, prepared by Nelson Geotechnical Associates, Inc., dated July 30, 2009
Area Drainage Quantities Site Plan, prepared by Norman & Norman, submitted August 3, 2009
Grading and Utility Site plan, prepared by Norman & Norman, submitted August 3, 2009
I have one comment on the letter from Nelson Geotechnical Associates but it does not effect the project (the design
infiltration rate of 0.25 inches per hour and the recommendations for the underdrian design are acceptable) . In the
future, please include the SCS soil textural classification system when describing collected soil samples instead of only
using the Unified Soil Classification system. The Dept. of Ecology Stormwater Management Manual and all equivalent
manuals use the SCS classification (based on % sands, % clay, and % silt) to assess the infiltration capacity of soil
samples.
Both the Area Drainage QuantitiesSite Plan and the Grading and Utility Site plan indicate the sizing the rain garden was
done using WWHM modeling software. Please include the all model input parameters, output runs, including but not
limited to: stage-storage-discharge relationship of rain garden, outlet pipe sizing, and discharges for the 10 and 100-year
return period events.
The Grading and Utility Site plan needs the following additions:
Calculations showing the sizing of the bioswale need to be included.
A more detailed specification for the bioswale vegetation (Other than "vegetation lining")
A detail showing inlet protection where the roof tight lines discharge in to the bioswale
A detail showing inlet protection where bioswale enters the rain garden
A more detailed specification for the rain garden soil (other than "organic rich soil"). See: "Rain Garden Handbook
for Western Washington Homeowners" at:
http://www.pierce.wsu.edu/Water_Quality/LID/Raingarden_introduction.pdf
Detail on the planting plan for the rain garden. "Rain Garden Handbook for Western Washington"
DATE MAILED/FAXED 8/18/2009 PAGE ____ OF ___
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A detail showing a cross section of the rain garden overflow over the rockery.
Sincerely,
Jerry Shuster, P.E.
Stormwater Engineering Program Manager
Please resubmit 3 copies of the revised plans/documents to a Development Services Coordinator. Please
contact me at 425-771-0220 if you have specific questions regarding these plan corrections.
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