eng20110266-Keros-drainage_permit-1.pdf
DATE: September 6, 2011
TO: Steve Waite
waitearch@comcast.net
FROM: Jeanie McConnell, Engineering Program Manager
RE: Application #: eng20110266 (plans being reviewed for this permit were originally
submitted under land use application PLN20110016-landscape modification)
Project: Keros Drainage Permit
Project Address: 22324-Highway 99
During review of the above noted application, it was found that the following information,
corrections, or clarifications are needed. Please revise and resubmit three (3) sets of
plans/documents with a written response to each of the items below to Jeanie McConnell.
City of Edmonds handouts, standard details and development code can be referenced on the City
website.
GENERAL
1.Where elevations are provided for pipe connections to catch basins, the elevation called out shall
be of the pipe invert instead of the top of pipe. Please revise plans accordingly.
2.Provide RIM and invert elevations for the CB at the City right-of-way. Invert elevations shall be
provided for all connections (existing and proposed) and at lease a small portion of the City
storm system within Edmonds Way shall be shown on the plans.
3.The invert elevation of the detention pipe at the control structure shall be the same as the invert
elevation for the outfall pipe and the storm detention pipe shall not be sloped more than 1%.
Current elevations indicate a 6% slope. Please revise plans accordingly.
4.Please indicate on the plans all pipe material and diameter for all sections of storm pipe.
5.Submit a traffic control plan for temporary sidewalk closure and lane closure as required in
order to connect to the City storm system.
6.The impervious surface area chart shall be revised to include existing impervious surface areas
on the parcel. Indicate whether existing impervious areas are exempt from the stormwater
requirements or if there is an existing storm management system on the site that mitigates these
flows. Ive attached to these comments a more current impervious surface area chart to assist
with this documentation.
7.An erosion control fence is shown on the plans, however, as this area falls within the existing
parking lot surface, the silt fence cannot be properly installed through trenching methods.
eng20110266-Keros-drainage_permit-1.doc Page 1 of 2
Alternative temporary measures should be used to capture sediment and prevent it from leaving
the site or entering the storm system. Sandbags or straw bales may be more appropriate.
IMPERVIOUS SURFACE AREA CHART:
Line Type Area (square feet)
1. Non-Regulated
Exempt Regulated
2. Replaced
3. New (Post 1977) +
Total Regulated Impervious Area
4. =
Mitigation required if in excess of 2000sf
-
5. Total Area Mitigated by Existing Stormwater Management System(s)
=
6. Regulated Area Not Yet Mitigated
=
7. Area Proposed to be Mitigated by Low Impact Development Techniques
=
8. Area Proposed to be Mitigated through Conventional SWM Techniques
Please contact me at 425-771-0220 or by e-mail at mcconnell@ci.edmonds.wa.us if you have
specific questions regarding these plan corrections.
Page 2 of 2