bld20100323-Piercy-1.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
ENGINEERING DIVISION
Public Works
Plan Review Corrections
Application:Date:
#bld20100323 September 3, 2010
Project Name/Address:
Alan and Inae Piercy Stormwater Review 733 Melody Lane
Contact Person/Address/Fax:
Peter Anderson 206-949-5828 panderson@voa.com
JoAnne ZulaufDivision:Engineering
Reviewer:
During review of the subject submittal it was found that the following information, corrections, or
clarifications will need to be addressed:
Peter – I have written up separate comments for each of the plans. I may not have caught all the smaller details
that would need correction as I concentrated mainly on the “pervious” vrs the “impervious”.
The addition of the arbors and the fence located in the setbacks would require a Fence permit so upon your
resubmittal the plans would also be reviewed by Planning and Building.
Another important item is the rockery. Rockeries are not regulated by the City other than in the setbacks no
structure over 3ft in height is allowed – excluding fences. Also any rockery near the right of way must be equal
in height to it’s distance from the property line. If the existing rockery meets either of the two exceptions above
andyou make any alterations to it then you would be required to meet the restrictions above, in others words,
bring in down to 3ft and pull it back 3ft from the property line.
Also, the river rocks would need to be included in your calculations. At this point I would say they need to be
considered impervious. I want to check with our stormwater engineer to be sure on this point though. Perhaps
if a “drywell” type of bedding underneath the rocks would suffice to meet a “pervious” classification.
I have also attached copies of the City’s Storm, Water and Sewer maps for the area. It appears that there is no
City storm located in the access road to this property. The storm system would need to be extended from
Melody lane along the access road to the property for connection. Expense and construction would be the
responsibility of the homeowner.
General Comments
1.The areas of river rock need to be included in the impervious surface calculations.
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2.Show existing and proposed topographical elevations.
3.Please note on plan grading amount, fill and/or cut amounts. If none, note “No Grading”.
4.Please show erosion and sediment control measures to be employed. Include detail of measures
consistent with City of Edmonds Standard Details. Available on the City of Edmonds website.
5.Show full extent of right of way including all improvements (storm main, water main, telephone poles
etc) .
6.Show all utilities on plan from property line to connection at house.
7.Add note to plans; “All converted or disturbed soils shall be compost amended”.
8.Include height and length of all fences. Add detail of design with plans.
9.Label all rockeries with top of wall elevation and bottom of wall elevation for every two feet of change.
10.Show all public or private easements on site.
11.
Pervious Plan Comments
1.All use of LID measures shall require a geotechnical soils report. I have attached information regarding
the requirements and accepted testing methods.
2.Pervious areas must have a slope of less than 5%. Please note slope of all areas.
3.Pervious areas can not accept runoff from any impervious areas. Please show how impervious sport
court runoff will be handled.
4.Will pavers for patio on west side of home be pervious? If so, the portion of impervious surface
replaced would be considered “converted”. Please label area clearly and if “converted” note square
footage in calculations. (This area would count towards a flow credit).
5.The stormwater supplement chapter 5.7.2 states than if a project generates greater than 2000 sf and less
than or equal to 5000 sf of new and/or non-exempt replaced impervious surface, and if the greater of
that 2000 sf or 85% of that surface, which ever is greater, is mitigated using LID measures, in this case
pervious pavers, then the flow control requirements are met. (For this purpose, all added surface is
considered impervious then the LID measure, in this case using pervious pavers, is counted as
mitigation of that surface). The calculations used to reach this requirement should be included in your
plans. See Table 5.3 and 5.4 for more information.
6.If impervious surface new and non-exempt replaced is greater than 5000sf then the thresholds stated
above are 5000 sf or 90% respectively.
7.Please include details of paver installation, paver manufacturer instructions are acceptable.
8.A special inspection by the geotech of record will be required during installation of pavers to confirm
installation meets requirements.
9.Pervious pavers may be installed to the edge of pavement in right of way. Show on plans.
Impervious Plan Comments
1.Detention sizing information included in plans is not consistent with 2010 Stormwater Code. Attached
please find current sizing information and include in plans.
2.If impervious surface added is under 5000 sf, detention sizing can be determined by using the City’s
simplified sizing chart (referenced above) to meet flow control requirements. If impervious surface
(new and non-exempt replaced) is greater than 5000 sf then detention system must be designed by a
civil engineer. A stormwater report is required including calculations showing how flow control
requirements shall be met.
3.Show location of detention system with all rim and invert elevations of catch basins.
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4.Show how the impervious surface runoff will be captured and connected to the detention system. Add
arrows to indicate flow.
5.Label all pipe with size, material and length. Label all “capture” structures with rim and invert
elevations to verify flow.
6.Show connection to City storm system. Include rim and invert elevation information for existing catch
basin at connection.
7.All pipe under drivable surfaces must be SDR 35 or better.
8. Impervious pavers must end at property line, asphalt must be installed from property line to edge of
pavement. Show on plans.
Please resubmit 3 copies of the revised plans/documents to a Development Services Coordinator. Please
contact me at 425-771-0220 or by e-mail at zulauf@ci.edmonds.wa.us if you have specific questions
regarding these plan corrections.
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