pln20160012 - Knob Hill SP - Civil 1.pdfof EIIAf CITY OF EDMONDS
CIVIL PLAN REVIEW COMMENTS
Y
ENGINEERING DIVISION
FSf. , gqo (425) 771-0220
City Website: www.edmondswa.gov
DATE: March 3, 2017
TO: Lee Michaelis — lee.michaelisgpugetsoundplanning com
Brooke Bland — brooke@ugetsoundplanning com
FROM: Jeanie McConnell, Engineering Program Manager
jeanie.mcconnell@edmondswa.gov
RE: Subdivision File #: pin20160012
Project: Knob Hill 4-lot Plat
Project Address: 19125 — 941h Ave W and 9302 — 192" d Pl W
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 an engineering technician.
Resubmittals can be made at the Development Services Department on the 2nd floor of City Hall.
Permit Center hours are M, T, Th & F from 8am-4:30pm and on Wednesdays from 8:30am-noon.
City of Edmonds handouts, standard details and development code can be referenced on the City
website.
GENERAL
1. Please provide an itemized engineers cost estimate for both on -site and off -site (right-of-way)
improvements, including all utilities, traffic control, and restoration/enhancement plantings.
Use the King County Site Improvement Bond Quantity Worksheet and utilize the "write-in"
sections where appropriate.
• A bond is required to be placed for all erosion control measures, right-of-way and
stormwater management improvements.
• If you intend to post a bond in order to record the subdivision and ahead of constructing
required improvements, the bond amount will be based on the entire scope of the project.
• The amount of the bond will be based on 120% of the City approved estimate. The City will
inform you of the appropriate bond amount after review of the cost estimate. Please obtain
the appropriate subdivision improvement bond forms from the City.
• Inspection fees for this project will be calculated at 3.3% of the 120% City approved
estimate for all improvements.
2. Please add a note to plans stating "A separate right-of-way construction permit is required for all
work within the city right-of-way." Please note, a ROW permit application with contractor's
signature shall be provided to the city prior to issuance of civil construction plans.
3. Revise the approval block on all plan sheets to state "City Engineering Division".
4. Submit a traffic control and haul route plan for review and approval. Individual plans shall be
provided for all elements of work to be completed on each street.
5. Where plan corrections affect multiple plan sheets, please update all.
Sheet C1— COVER SHEET
1. Include construction sequence. Refer to sample on City website.
2. Include General Construction Notes. Refer to sample on City website.
3. Provide Utility Purveyor information.
4. The Engineering Requirements established as conditions of short plat approval state "192nd St
SW, 94' Ave W, and 192n1 PI SW to be widened along property frontage to provide for an 1I-
foot travel lane closest to the development". This shall be interpreted to mean 11-feet from the
center of existing pavement towards the development. The plans currently show widening
throughout to meet street standards for the entire street section at 22-feet in width. Where there
is insufficient right-of-way to provide the additional 11-foot travel lane width nearest the
development, then widening may be necessary on the street edge opposite the development.
Revise plans accordingly and address the following:
a. Topography — slopes adjacent to existing road — will a 2:1 slope be maintained post
street widening?
b. Existing vegetation adjacent to pavement widening. What impact will the widening
have on existing trees or their roots?
c. Existing infrastructure/utility locations (fire hydrant, catch basins, power poles, fences,
etc.) and setback requirements from edge of pavement.
d. Fences, retaining walls and rockeries shall be located on private property and shall be
shown on the plans to be removed and replaced as needed.
e. Construction of a "reservoir rock shoulder" is not consistent with City street standards.
Refer to standard detail E-2.1.3. 18" curb and gutter or asphalt thickened edge shall be
provided to City standards.
5. Please clarify what the "storm easement" on Lot 3 is for. All stormwater management systems
shall be privately owned and maintained.
6. Driveway approaches are to be constructed as part of the subdivision. Clearly delineate
driveway approaches and indicate proposed surface material. Construction of the driveway
approach on Lot 3 will also protect the infiltration gallery proposed for installation under the
driveway.
7. Rockeries are prohibited in certain situations according to Edmonds Community Development
Code (ECDC) 18.40.020. Please revise the rockery as shown on Lot 3 to be setback from the
ROW a distance equal to the height of the rockery.
8. Utility patches shall be combined and full width or half width overlay will be required
depending on the extent of disturbance. Where utility patches fall entirely within one travel
lane, the overlay shall extend to the centerline of roadway. Where utility patches extend into
both travel lanes then a full width overlay is required.
Sheet C2 — CIVIL SITE PLAN DETAILS
1. Update Section details 1 & 2 to be consistent with comments noted above under Sheet C 1.
Page 2 of 6
Sheet C3 — STORMWATER MANAGEMENT PLAN
1. Impervious Areas chart: Provide a breakdown for road and each single family residence
(showing house and driveway separate). This information will also need to be shown on the
face of the recording documents.
2. Please take note of the following related to stormwater improvements for the subject
development:
The Supreme Court of Washington issued a ruling on December 29, 2016 regarding the "vesting" of
Stormwater regulations. This ruling upholds the Department of Ecology's regulations for application and
construction dates for projects with Stormwater requirements.
The City of Edmonds has received clarification from the Department of Ecology on what this ruling means for
development applications submitted prior to local stormwater codes being adopted. The stormwater codes in
effect at the time the application for a plat/subdivision is submitted apply to all subsequent building permits if
stormwater is being addressed at the subdivision/plat level. If the subdivision included restrictions or
requirements for the individual lots, (e.g. maximum impervious surface, LID BMP's), those requirements
should be recorded for each lot and must be enforced when the individual lot is developed.
Under the municipal stormwater permits the only place that the recent supreme court decision comes into play
is if the developer does not start construction on the plat/subdivision until after January 1, 2022.
For the purposes of the municipal stormwater permits both "application " and "start construction " are defined
in the permits.
Application means at a minimum, a complete project description, site plan, and if applicable SEPA checklist.
Start of construction means at a minimum, the site work associated with and directly related to the approved
project has begun. For example: grading the project site to final grade or utility installation.
Language shall be included on the face of the recording documents for the plat/subdivision that states the
stormwater codes in effect at the time of application for the plat/subdivision shall apply, as long as
construction on the plat/subdivision starts prior to January 1, 2022. If construction does not begin prior to
this date, the stormwater system for the plat/subdivision shall be redesigned to comply with current codes.
3. Infiltration systems have been shown on the plans, but a note has been added that states
"Infiltration trench has been sized for a generic house footprint and configuration and should be
verified for adequacy prior to construction". In order to be vested to 2016 stormwater codes,
infiltration systems will need to be designed for a specific amount of impervious surface area
and the recording documents will need to clearly state these areas. As allowed by the
Engineering Requirements as a condition of short plat approval, construction of the stormwater
management systems can be deferred to the single family residence; however, the design of the
storm system will then need to comply with codes in effect at the time of building permit
submittal.
4. With widening of 192nd PI SW, the stormwater flows can be accepted onto private property
with a properly sized stormwater system. As noted above, the storm system will remain private
and the rock reservoir will not be allowed along the road edge. Revise to curb and gutter or
asphalt thickened edge and ensure placement of the catch basin within the flow line.
Sheet C4 — STORMWATER MANAGEMENT DETAILS
1. Detail 1 — Infiltration Trench Section:
a. Provide 2-feet cover over infiltration gallery or move outside of drivable area.
b. Revise slope of finished grade if gallery remains under the driveway.
Page 3 of 6
2. Storm structures shall be revised to Type II storm manholes as RIM to invert elevations exceed
5-feet. The storm drainage notes reflect compliance with this requirement, but the details
indicate ADS N-12 pipe will be installed.
3. Utility stubs shall be marked on the property with a 2x4 wooden stake marked with appropriate
utility.
Sheet C5 — WATER/SEWER PLAN
1. A 6" cleanout has been shown at the property line of lots 2 and 3 and a stub shall also be
provided on private property. Please revise.
2. Provide sewer invert elevations at the main line and the stub.
3. Sanitary sewer connection at the main shall be with a romac inserta-tee. Add note to plans.
4. Note pipe size and material on the plans.
5. Clearly show existing water and sewer lines for lots 1 and 4. Are utilities located entirely within
the individual parcel, or will easements be required?
6. Meter(s) shall be placed on right of way side of property line and outside of driveway approach.
Revise plans accordingly.
7. Please confirm size of meter to be installed to Lots 2 & 3. A 1" meter is typically sufficient for
a SFR that is required to be sprinkled per fire department requirements.
8. Utility stubs shall be marked on the property with a 2x4 wooden stake marked with appropriate
utility.
9. Underground Wiring Requirements of ECDC 18.05 shall be followed. All utility services shall
be installed underground.
10. Show location of dry utilities and required utility separation (5-feet from City utilities within the
ROW and 3-feet from water/sewer/storm utilities on private property).
Sheet C7 — CONSTRUCTION SWPP PLAN
1. Tree protection measures are to be shown on this plan. Where trees are to be maintained barrier
fencing shall be placed at the drip line of the tree in order to protect the root system.
2. A rock construction entrance shall be provided. Include City standard detail on sheet C8.
3. Show stockpile location and indicate requirements to keep it covered.
4. Add note: "disturbed areas to be compost amended". Refer to City handout E72C for specific
requirements to be called out on the plans.
STORMWATER REPORT
The following comments are provided from Robert Edwards, Stormwater Engineer. Please
contact Robert directly at 425-771-0220 or by email at Robert.edwards(dedmondswa.2ov with
any specific questions you may have regarding these comments.
Background
This is classified as a Category 2 Small Site because it proposes impervious area exceeding 5,000
SF.
Category 2 Small Site Projects are subject to Small Site Minimum Requirements 1, 2, 3, 4, 5, 6, 7,
8, 9, 10, and 11.
Minimum Requirement #1— Preparation of Stormwater Site Plan
Comments:
1. Sheet C4, Washed rock specification shown as "3/4" TO 1-1/2'"' should be 1-1/2" to 1-3/4"
per E7213.
Page 4 of 6
Minimum Requirement #2
— Construction Stormwater Pollution Plan
Comments: None
Minimum Requirement #3
— Source Control of Pollution
Comments: None
Minimum Requirement #4
— Preservation of Natural Drainage Systems
Comments: None
Minimum Requirement #5
— Onsite Stormwater Management
Comments:
1. Provide WWHM project reports for each infiltration trench.
2. WWHM modeling of infiltration trench porosity should be a void ratio of 0.30
Minimum Requirement # 6
— Runoff Treatment
Comments: None
Minimum Requirement #7 —
Flow Control
Comments: N/A
Minimum Requirement #8 —
Wetland Protection
Comments: N/A
Minimum Requirement #9 —
Operation and Maintenance
Comments:
1. Provide O&M for infiltration trenches.
Minimum Requirement # 10 — Offsite Analysis and Mitigation
Comments: None
Minimum Requirement #11— Financial Liability
Comments: N/A
PLANNING DIVISION COMMENTS
The following comments are provided from Mike Clugston, Associate Planner. Please contact
Mike directly at 425-771-0220 or by email at mike.clu2ston(dedmondswa.2ov with any specific
questions you may have regarding these comments.
I have reviewed the civil improvement plans submitted on December 30, 2016. The following
comments are in reference to the listed conditions of approval from the preliminary short plat
decision of October 19, 2016 and the Edmonds Community Development Code (ECDC). The
following comments must be addressed before review can continue:
2.
3. Vegetation Management Plan: Please submit a vegetative management plan that demonstrates
how the project complies with the 30% native vegetation requirement of ECDC
23.90.040.C. While Attachment 6 of the approval decision shows a `vegetation management
zone', no information was included with the civil plans on how the identified area will be
established or maintained pursuant to Condition 2 of the preliminary decision. Please provide
written documentation (either as notes on plan sheets for a native vegetation area or as a
separate document) addressing the following:
4. Identify how much total area is included for native vegetation — 30% of the total lot area is the
minimum requirement.
5. Describe the vegetation that is currently present within this area, including descriptions of what
existing vegetation is native, non-native, or invasive.
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6. Describe what work is needed in order to remove any existing non-native or invasive species
from within this area (if any non-native or invasive species are currently present within this
area).
7. Describe what work is needed to establish this area as native vegetation (i.e. addition of native
groundcover, shrubs, or trees in order to replace any non-native or invasive species that must be
removed).
8. Include provisions for maintenance of the native vegetation area (i.e. how will this area be
maintained in the future, what will be done for control of invasive species, how will any
vegetation that requires removal in the future be replaced?)
9. Please provide detail on when the vegetation management plan will be implemented (i.e.
following civil improvements, with building permits, some combination of both). If the
vegetation management plan will be implemented in phases, please describe.
10. For an example of how this information could be presented, review the landscape plan attached
to PLN20150053. The permit is searchable here: https://permits.edmonds.wa.us/citizen
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