pln20130020-Soundview Lane-Civil Comments 1.pdfof Ego CITY OF EDMONDS
�~ CIVIL PLAN REVIEW COMMENTS
ENGINEERING DIVISION
A, St1 g90 (425) 771-0220
City Website: www.edmondswa.gov
DATE: August 11, 2014
TO: Rob Michel
rwmichel@nwlink.com
FROM: Jeanie McConnell, Engineering Program Manager
RE: Subdivision File 4: pin20130020
Project: Soundview Lane — 3 lot SP
Project Address: 7231 Soundview Lane
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.
City of Edmonds handouts and standard details can be referenced on the City website under Permit
Assistance.
GENERAL
1. Please provide an itemized engineers cost estimate, including units and unit prices, for both on -
site and off -site (right-of-way) improvements, including all utilities, traffic control, NGPA
fencing and restoration/enhancement plantings. Please 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. Posting a bond for stormwater systems applies to
subdivisions that involve 7,000 square feet or more of land disturbing activity and as well as
on projects in a critical area or buffer including ESLHA. 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.
• If you intend to post a bond in order to record the subdivision, the bond amount will be
based on the entire scope of the project.
• Inspection fees for this project will be calculated at 3.3% of the 120% City approved
estimate for all improvements.
2. Please submit a traffic control and haul route plan for review and approval.
3. 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. A ROW permit application with contractor's signature shall
be provided to the city.
4. Please provide a written response from the geotech that the civil plans are consistent with the
geotech report.
5. Please note, special inspections will be required for public road compaction and construction of
all elements of the private access road and drainage installation (related slope stability &
foundation support).
STORMWATER REPORT
The following comments were provided from Jerry Shuster, Stormwater Engineer on July 28,
2014. Please contact Jerry directly at 425-771-0220 or by email at
ierry.shuster(&,edmondswa.2ov with any specific questions you may have regarding these
comments.
Drainage Report:
• Minimum Requirement 44
1. The geotechnical report dated March 13, 2014 states: "The proposed dispersion trench
appears to be located in an area that minimizes site impact. The dispersion trench is
located near the toe of the slope outside of steep areas ...... it should not have any adverse
effect on site stability." These type of outfall systems are covered in Volume V, Section
4.5.3 of the 2005 Ecology Stormwater Management Manual for Western Washington.
The design on plan sheet 1 for the dispersal trench corresponds to the Ecology Manual
figure 4.8. Figure 4.8 states that a 15% maximum slope water quality treatment.
First, based in plan sheet C 1, the dispersal trench is not located near the toe of the
slope as discussed in the geotechnical report. Second it appears that the slope ftom
the edge of the dispersal trench to the bottom of the ravine is greater than 15%. Also,
based on the contour lines down gradient of the dispersal trench on sheet C 1, the
flow will concentrate soon after leaving the dispersal trench and potentially cause
erosion and sedimentation problems downstream. A) Modify the dispersal trench for
water quality treatment or provide a separate treatment system. Also modify it so it
does not concentrate flow immediately downstream. B) have the geotechnical
consultant review the changed dispersion trench design and look for effects on the
down gradient slope and not just how it will affect the residential site proposed.
• Minimum Requirement 97
2. Explain what is meant by "minus bypass" in the impervious area exhibit.
3. The modeling uses 0.16 aces of driveway as "Flat." The Soundview Lane part of
that impervious should be broken out in the model as "moderate" since it has greater
than 5% but less than 15% slope.
4. Riser is modeled using an 18 diameter pipe but shows as a 12 in diameter pipe on
Sheet 1, detail 6.
Plan Sheet C1:
1. Add another CB along the east side of Soundview Lane. 275 feet is at its proposed
slope is too long of a flow path to one CB, even with the proposed raised edge. For
City -right-of-way:
■ For grades less than 8 percent, catch basin spacing shall be a maximum of 300
feet.
■ For grades from 8 to 12 percent, catch basin spacing shall be a maximum of 200
feet.
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■ For grades greater than 12 percent, catch basin spacing shall be a maximum of
150 feet.
2. Incorporate City of Edmond standard detail 5.4 (flow control structure) into the
plans.
PLANNING DIVISION COMMENTS:
The following comments were provided from Jen Machuga, Associate Planner. Please contact
Jen directly at 425-771-0220 or by email at ien.machuga(aedmondswa.gov with any specific
questions you may have regarding these comments.
1. As stated in the conditions of preliminary short plat approval, pursuant to ECDC 18.40.020.A.8,
rockeries are prohibited within Landslide Hazard Areas. Therefore, any necessary changes must
be made to the civil plans such that no rockeries are proposed within any Landslide Hazard
Areas and such that the proposal complies with the rockery prohibitions of ECDC 18.40.020.
2. As stated in the conditions of preliminary short plat approval, rockeries and retaining walls
located within minimum required setback areas shall not exceed three feet in height as measured
over original grade. Please include documentation indicating that any proposed
rockeries/retaining walls comply with this requirement.
3. Please add the following note to the civil plans: "Approval of these plans does not constitute
approval of the single-family residences and associated setbacks as shown. A separate building
permit is required for review and approval of the single-family residences."
4. Clearing limits are indicated around the entire perimeter of the property; however, work
associated with the civil improvements is not being conducted throughout the entire site. In
particular, no work is being conducted on the northern and western portions of the site, so there
is no need for the clearing limits to extend around the perimeter of the entire site. Additionally,
the clearing limits shown conflict with the provisions of the vegetation management
plan. Please revise the clearing limits so that they only encompass those portions of the site that
require disturbance necessary for the civil improvements and so that they do not conflict with
the vegetation management plan nor with any existing trees that are to be retained.
5. Please include measures to protect all existing trees that are to be retained pursuant to ECDC
18.45.050.H.
6. Thank you for providing a vegetation management plan. Please revise the plan to address the
following:
a. Provide further description of how the invasive species will be removed and how the
new plants will be planted (i.e. type of equipment to be used). If equipment beyond
hand tools is necessary for the work outlined in the vegetation management plan,
please describe.
b. The monitoring plan states that if more than half of the plants die during the first two
years, additional plants will be added. This is a low measure. Typically, monitoring
plans strive for a minimum of 80% survival within the first few years. Please revise
accordingly.
c. Include provisions for how any future changes to the boundaries of the native
vegetation area or to the vegetation management plan could be made if so desired by
the current or future property owner(s).
d. 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.
Page 3 of 5
New Sheet — SITE DEVELOPMENT PLAN
1. Provide a Site Development Plan as the cover sheet that shows the original parcel, proposed
property lines, Soundview Lane road improvement, access easement, utility easements, etc. The
intent of this sheet is to provide a clean and clear overview of the project.
2. Utility contact info, sheet index to be shown on this plan sheet.
3. The general notes provided on Sheet 3 could be provided on this plan sheet.
Sheet 1 of 3 — ROAD & DRAINAGE PLAN
4. Revise sheet title to state "Road, Drainage and Utility Plan".
5. Proposed water services shall be shown a minimum of 3-feet from the existing blow -off.
Services shall extend perpendicular from the water main line to the property line. Easements
shall be provided across Lot A as needed.
6. An additional catch basin shall be provided in Soundview Lane. The one catch basin at the end
of the road and near the slope is not sufficient for the amount of impervious surface runoff.
7. Please revise the yard basin detail to show a concrete bottom.
8. Please refer to detail 5 in plan view.
9. Catch basin grates in Soundview Lane and the private access road shall be vaned grates. Please
revise plans and details accordingly.
10. As shown in plan view, Section A -A runs from the north line of Lot C to the south line of the
private access road. The detail of Section A -A only provides detail of the spreader trench itself.
11. An intersection street sign shall be provided at the intersection with designation "Soundview
Drive" and "Soundview Lane". The private address sign for lots B & C shall be shown at the
private access drive for those lots.
12. A stop sign may be required at this intersection. Clarification is currently being sought from the
City traffic engineer.
Sheet 2 of 3 — TESC & GRADING PLAN
1. Revise sheet title to state "TESC, Grading and Demolition Plan".
2. This plan sheet shall be provided in the plan set ahead of the Road, Drainage and Utility Plan.
3. Revise clearing limits as noted in the Planning Division comments provided above.
4. Several trees proposed for removal are shown to be located within the City right-of-way. Please
provide documentation showing these trees will not provide marketable timber. If the timber is
marketable, the money provided to the owner/developer for removal of the tree(s) will need to
be paid to the City.
5. 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.
6. A rock construction entrance shall be shown on the plans and City standard detail referenced
and incorporated into plan set. Please revise accordingly and add a noted that states the existing
asphalt driveway shall be maintained for as long as possible.
7. Will any soils be stockpiled on the site? If so, show stockpile location and indicate
requirements to keep it covered.
Sheet 3 of 3 — PROFILES NOTES & DETAILS
1. Revise the General Notes to reference the 2014 WSDOT Standard Specifications.
2. Revise detail 1 to callout road subgrade and asphalt requirements. Specifications shall be
consistent with City standard detail E2.1.3.
Page 4 of 5
3. Revise detail 4 to callout road subgrade and asphalt requirements. Specifications shall be
consistent with City standard detail E2.1.
Please contact me at 425-771-0220 or by e-mail at Jeanie.mcconnell(aedmondswa.2ov if you
have specific questions regarding these plan corrections.
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