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Edmonds
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Ke gel &Associates Inc.
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August 22, 1977
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Planning Divisign
City of ' Edmonds
City Hall
Edmonds, Washington 98.020
Re: Storm Drainage Analysis of Proposed Park Mere West Development'
Our Job No,. 6886
Gentlemen.
Proposed Design:
A. Storm water runoff• will come from two main sources:
1• Road surfaces
2. Roof areas:
Runoff fromiroad surfaces will be intercepted by roadside gravel,
filled trenches. These trenches will detain the water until it
can be leached into the underlying soil
Runoff from roof surfaces will be intercepted by standard roof g;
} and footing dra.ins. This water will also be detained and eventually.
will leach into the soil by means of gravel sumps located on each
lot. On slopes exceeding 25%, these sumps will take the form
ch an ar
of trenches running parallel to the contours.
uof subsurfarance
y:
will prevent slippage due to high concentrations}
water on steep slopes.
soils analysis and percolation -rates indicate
B. The accompanying
s`> a suitable depth and quality of material that should adequately_ i
absorb the storm water runoff as ground. water recharge. Therefore
earin and regrading for an additional detention area
extensive cl 9
in the common space may be entirely eliminated or scaled down ;.
in size.from that originally designed.
C. The existing culvert under 68th Avenue West and the drainage
I`
g
�., channel running east -west across -the subjectproperty will not
be altered.
Soils: {`
A percolation test and a soil log on each lot were performed
U11
by Mr. Warren Williams, a registered sanitarian (See Appendix).
ENGINEERS • SURVEYORS PLANNERS
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