20110131111421636.pdfCity of Edmonds
121 5'r" AVENUE NORTH EDMONDS, WA 98020 - (425)'771-0220 FAX(425) 771-0221
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Website:
PUBLIC WORDS DEPARTMENT
Engineering Division
Plan Chccfc#: BLD20100758-ReSU6ll1 Date: January 26, 2011
Project Name/Address: — Clea
SFR 22804-96"' PI W (Lot
ContactPerson/Address/Fax: Tom Berg tomberg58@)yahoo.com
Reviewer: JoAnne Zulauf Division: E ngineerin
During review of the subject submittal, it was found that the following information, corrections, or
clarifications would need to be addressed. All Handouts and Standard Details referred to in these
comments can be accessed at our website: wivn ' , ',,ci 'e' .' In '' ' on ' c s '.)i,a, w,is by clicking City Government / City
Department / Public Worlo / Engineering Division:
ilfoto "'. 1314fil(fitig �J'o not fip'Clude mIlpda.ted "o
]±laigineerhlr' ffandotqt;" for all Reqdrenwiaft.
'1/20/11 Not [)one. Drainage plan will not be reviewed by the Stormwater Epg neer as submitted. See
comments under Stormwater Mitigation.
1. 1/26/11 Dorie.
2. 1/26/11 Not Done, Please show bump out on plans.
3. 1/26/11 Not Done. Plat map calls out a 50' of the east side of the property for a snoho trans
easernent. Please provide a copy of the City of Edmonds drainage easement noted. Is the
drainage system private or public?
4. 1/26/11 Not Ione. Is a retaining wall planned for this property? If so, please show on plans
and note bottom of wall (bow) and top of wall (tow) elevations at each end and for every two
feet of change.
5. 1/26/11 Not Done. Add note to plans: "Replacement is required of any plat improvements
that are damaged during construction."
7. 1/26/11 Not Done. Show dimensions of structure, deck, driveway length and width at road and
property line.
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8. 1/26/11 Done,
9. 1/26/11 Done.
10.1 /26/11 Not Done. Please add a general notes section to the civils. Please refer to example
provided with the comments for Lot 7.
11. 1/26/1"1 Done.
12A/26/1 -1 DCHIE"
GrRding/TESC:
1. 1/26/11 Not Don e. Please include details of erosion control measures in plans consistant
with City of Edmonds standard details. Also add note to plans "Additional Ecrosion Control
Measures Consistent With City of Edmonds Standards Provided As Needed".
2. 1/26/11 Not Done. Please change grading calcs from yards to cubic yards.
3. 1 /26/11 Not Done. Please review minimum requirements of erosion control for the
classification of the project. Add all minimum requirements to the civil general notes
section.
4. 1/26/11 Not Done. Indicate area of disturbance. Outline on grading/tees plan and label
with square footage of the area.
5. Add note to plans: "All disturbed areas on and off site shall be compost amended to meet
requirements of BMP T5.13 in the Stormwater Manual, Vol V, Chapter 5.
Stonnivater M : (same, commelits''w", provided with Lot'/)
1/263/11 Not Done. The inforrnation listed below Must be presented prior to the City evaluating
the stormwater design for the project. Please review the Stormwater Handout E72 and the
Stormwater Supplement, both available on our website.
2. 1/26/11 Not Done. The project needs to be classified per ECDC 18,30.50. Once classified,
the report should describe how the project plans to comply with applicable minimum
requirements (See Handout E72)
3. 1/26/11 Not Done. Please provide a completed copy of the Worksheet available in Handout
E72.
4. Lot 8 requires onsite stormwaer rnitigation per Jerry Shuster, Stonw/vater Engineer.
Developing Lots 6, 7, and 8 as proposed will result in a total of 34,366 sf of impervious surface.
The ston-nwater system constructed in 2001 was designed for an impervious Surface total of
30,260 sf meeting the design flow rates of that time. The existing construction of the five lots
(17,181 so and the CUI de sac road and sidewalks (10,240 sf) equals 27,421 sf of impervious
surface that is mitigation by the City approved system meeting the code requirements of 2001,
1 -he mitigation of runoff for the proposed impervious surface, 6945 sf, may be approached in
several ways;
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a) Provide engineered calculations that show the existing system has the capacity to
handle the existing and proposed impervious surface runoff (34,366 sf). (includes all 3
proposed lots)
i) Project would be categorized as a Large Site project. See Chapter 4 of the
Stormwater Supplement for requirements.
ii) System sizing would need to meet Current stormwater code flow control
requirements. See Chapter 4 of the Stormwater Supplement to find flow control
requirements for runoff In a direct discharge basin, available on the City of
Edmonds website,
iii) Soils infiltration testing by an approved method (see Supplement Chapter
4.5.2) is required for any system design using infiltration.
iiii) Physical verification of the current condition and size of the bio swale
described in the 2001 Stormwater Report for this project is required if intended
for the stormwater mitigation of the proposed construction on lots 6, 7, and S.
b) Propose an engineered plan adding increasing capacity of -the existing system. (same
requirements as 2 a above)
c) Leave existing system untouched and propose a separate system to meet storrnwater
requirements for only the proposed additional impervious surface, 6,945 sf.
i) Project would be categorized as a Small Site project Category 2 if -the three
lots will use a shared system for mitigation. If the lots are mitigated individually
each would be considered a Small Site Category 1. See Chapter 5 of the
Stormwater Supplement for more information.
6. 1/26/11 Reference. Appendix C of the Supplement provides the acceptable methods for
obtaining a design infiltration rate for infiltration trenches. In addition to the methods in Appendix
C of the Supplement, the City also accepts the "110 methodology" described in Volume 111,
Section 3.36, number 2 (including Table 3.8) in the 2005 Department of Ecology Stormwater
Management Manual for Western Washington. Once the design infiltration rate is established,
the City has tables for determining the size of the infiltration trench based on the square feet of
impervious area draining to the facility or the sizing can be obtained by the applicant using the
modeling parameters in the Supplement. Attached please find a simplified sizing tool for low
impact development or detention systems. This tool can P-ely be used for projects that are
categorized as Small Site Category 1 or 2 sites (under 10,000 sf imp surface).
Drain U#_ Plan:
1. 1/26/11 Not [Done. Flow will the runoff from the driveway be connected to the stormwater
system? Show on plans.
2. 1/26/11 Done,
3. 1/26/11 Done.
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5. '1126/11 Not Done. Show existing storm line on plans. Include rim and invert elevations at all
catch basins.
6. 1/26/11 Not Don o. The full extent of all detention or other stownwater mitigation systems must
be shown on the Drainage Plan. Include all rim and invert elevations, pipe size material and
length, catch basin type, and swale dimensions.
7. '1/26/11 Not Done. Show connection of tightline/roof drains to storm system from house to
storm line in easement. A catch basin Must be installed at point of connection. Provide rim
and all invert elevations.
8. 1/26/11 [)one,
9. 1/26/11 Done.
10.1/26/11 Add water line to p', laps. Show all utilities on plans (sewer, gas, power, water) from the
connection at the property line or easement to the point of connection to the, residence.
11.1/26/11 Done.
12. 1/26/11 Not Label all pipe with length, material and size.
Please resubmit 3 copies of the revised plans/doctiments to as Development Services Coordinator. Please
contact me at 425-771-0220 if you have specific questions regarding these plan corrections.
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