bld20100345-Stewart-E2.pdf
DATE: July 23, 2010
TO: Lydia Marshall
Red Cottage Studios
Lydia@redcottagestudios.com
FROM: Jeanie McConnell, Engineering Program Manager
RE: Plan Check #: BLD20100345
Project: Stewart Single Family Residence
Project Address: 919 Cedar Street
During review of the above noted application, it was found that the following information, corrections,
or clarifications are needed. Please redline plans or submit three (3) sets of revised plans/documents
with a written response to each of the items below to Linda Thornquist.
City of Edmonds handouts and standard details can be referenced on the City website under
Development Services Department, Engineering Division.
Review 1 June 23, 2010
Review 2 July 23, 2010
General
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7/23/10 Owner is currently working to finalize covenant.
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6/23/10 comment - Please complete the attached rain garden covenant and submit to the City for
approval. The final approved document will need to be recorded at Snohomish County and can be
processed by the City (for a fee) or by the applicant. Please inform of your preference when you
return the covenant.
7/23/10 City is still working on policy. Policy will be completed prior to permit issuance. No
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action required by applicant.
6/23/10 comment - The LID pilot program documentation is still being worked on by the City.
Additional information will follow these plan comments.
Stormwater Engineer Review
7/23/10 Please respond to the following:
a.Provide documentation that small site minimum requirements (SSMRs) have been
met in accordance with ECDC 18.30. Compliance with required SSMRs can be
outlined on the plans or provided in a stand alone document. Note, even though flow
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control is not required due to effective impervious area being under 2000sf,
acknowledgement of this SSMR is still required.
b.Please provide information on how the rain gardens were designed. The Rain Garden
Handbook provides a worksheet that is intended to assist with the design and
something as basic as this is all the City is looking for.
c.Please revise impervious surface calculation to show total square footage of areas and
then a separate column that indicates the allowable pervious pavement credits.
Provide grand totals for each of these two columns.
d.Indicate on the plans the slope of the individual areas that are eligible for pervious
pavement credit and provide a cross section of each area. Slopes have been provided
on the site plan, however, as the slopes are critical to determining the percentage of
credit received for the pervious pavement, the information needs to be provided on the
drainage plan as well.
e.It is unclear from looking at the drainage plan and the site plan which portion of the
roof will be constructed as a green roof. Please revise plans to clearly shown this.
f.The green roof is part of the stormwater management system and therefore details on
soil thickness, drain rock, etc. need to be included on the drainage plan.
g.The response letter states any water leaving the roof will flow through conventional
gutter and be directed via a rain chain per the civils. The civil plans do not show the
location of the rain chain or what will happen to the water once it reaches ground
level. Please revise accordingly.
6/23/10 comment - City staff received an e-mail from Robert Foley of Robert Foley & Associates on
June 8, 2010 informing that the stormwater management plan is still evolving. Therefore, review of the
subject drainage plans by Stormwater Engineer Jerry Shuster is limited. As noted below, certain items
have been flagged as requiring additional work by the design team.
1.Under the new storm code (eff. 6/1/10) permeable pavement is allowed to mitigate the runoff from
impervious surfaces. The permeable pavement can only mitigate for itself and not receive runoff
from any other part of the site. The flow control credits for this pavement are as follows:
Flow Control Credit
Minimum Design Soil Aggregate (up to <5,000 square
Slope Infiltration Rate (in/hr) Depth feet of pavement)
Up to 2 % 0.13 3 inches 100 %
>2% to 5% 0.13 3 inches 94%
>5 % Not recommended without detailed engineering analysis
2.The plans mention a green roof. More detail on the design and intent of this roof is needed.
3.The Edmonds Stormwater Code Supplement provides details on using rain gardens at single-family
residential sites. The design team should read these details carefully before designing any rain
gardens on the site.
4.It is recommended that the design team visit the City website to look at the Stormwater Code
Supplement for more information (http://www.ci.edmonds.wa.us/strm_wtr_mgmt.stm) on all these
issues.
Sheet A1 - Site Plan
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7/23/10 The City is continuing to work on the easement document and will forward to the
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owner for review prior to recording.
6/23/10 comment - A pedestrian easement will be required for that portion of the public sidewalk
located on private property. An easement document is currently being reviewed by the City
attorney and will be forwarded to you for review once complete. Before the easement can be
finalized I will need a copy of the new legal description for the subject property. Snohomish County
records do not appear to be up to date with this information. The easement area is proposed as the
south seven-feet (7) of the east thirty-feet (30) of the subject parcel. Please show the easement
area on the site plan.
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7/23/10 Revise to show driveway and rockery, similar to what is shown on Sheet C-2. Please
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also see comment #2 under Sheet C-2 below.
6/23/10 comment - Clearly show the revised boundary of the driveway on the adjacent parcel.
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Sheet C-1 - Grading, Drainage and Erosion Control Plans
(Some of these items are now found on sheet C-2 Grading, Drainage & Utility Plan)
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7/23/10 The water service line has been relocated and is now shown to be within the limits of
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the driveway. At a minimum, please locate the water meter just west of the driveway, outside
the concrete drive surface.
6/23/10 comment - The water meter shall be located in the City right-of-way at the edge of the
property line.
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7/23/10 Thank you for providing impervious area totals on the drainage plan. Please revise
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consistent with comment c under stormwater engineer review.
6/23/10 comment - Impervious surface area calcs shall be provided on the drainage plan (as well as
on the site plan).
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9.Add reference to silt fence and rock construction entrance details provided on sheet C-2.
10.Rain garden and stream channel construction details, including cross sections, shall be included in
the plan set and referenced on this plan sheet.
7/23/10 Comment addressed except for drainage from green roof. Please revise consistent
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with comment g under stormwater engineer review.
6/23/10 comment - Indicate on plans point of connection from roof downspouts, driveway drains,
etc. to the rain gardens.
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7/23/10 Proposed rockery along the east property line of 919 Cedar appears to be supporting
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a surcharge from the driveway above serving 923 Cedar. Rockeries are not designed to
support a surcharge. Please extend the section view of Detail 2/Sheet 4 to include the rockery
or retaining wall and the driveway above. If this area is redesigned to incorporate a retaining
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wall and the wall supports a surcharge then engineered design & calcs will need to be
submitted to the City. Peer review and special inspections are required for retaining walls
over 6-feet in height.
Sheet C-2 Drainage and Erosion Control Details (now Sheet C-3)
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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.
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