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BEYLER
CONSULTING
November 26, 2019
Zack Richardson, Stormwater Engineer
City of Edmonds
121 51h Ave N, Edmonds, WA 98020
Phone: 425-771-0220
CHUNG LOT 1
BLD20181098
721 EDMONDS WAY
Dear Zack,
RESU19
DEC 10 2019
BIM�&DEP
SE M
)MOIVEW
M
S'Ganrieo
Please find attached revised site plans, which reflect the changes as requested in the plan
review dated November 7, 2019. Our response to each comment is shown below in bold.
1. The architectural site plan refers to civil drawings for grading and drainage but no civil
drawings were submitted. A site -specific site plan showing grading and drainage along with
the improvements proposed under this permit, is required.
Update: It appears the topographical file may have been updated and now presents some
conflicting information that needs further attention as notes:
a. The 289 contour appears to run along the existing sidewalk as shown, and suggests a
steep slope within the sidewalk cross slope; check topographic contours for accuracy
and update remaining grading information as needed and noted below.
b. With the contours shown, it appears a low spot would be created along the back of
side somewhere between the proposed 289 contour on -site and the existing 289
contour in the sidewalk as mentioned above.
c. Existing contours also suggest that the driveway elevations are not feasible as they
would not match existing conditions at back of sidewalk.
d. It appears the swale behind the house is elevated above the finish floor elevation and
is not reflected in the proposed contours; adjust or updated as need to ensure Swale
achieves positive drainage to protect the proposed structure as intended.
e. Check footing drains and ensure positive daylighting is achieved with corrected
topographic information.
The grading has been revised. The area between the sidewalk and the end of the
ditch is now less steep. There are no low points between the property line and the
sidewalk. The driveway elevations at the sidewalk are matching the elevations from
the approved short plat plans. The swale behind the house has been lowered.
3. Include an erosion and sediment control plan and ensure it protects the infiltration facility
areas from construction traffic.
LAKEWOOD OFFICE
5920 J00Lh St SW' Ste #25
Lakewood, WA 98499
phone: 253-301-4157
fax: 253-336-3950
Plan. Design. Manage
CIVIL & S I RUC I URAL ENGINEL RING I LAND SURVEYING I PLANNING
PROJECT MANAGEMENT I FEASIBILITY I PERMIT EXPEDITING
Up-da e: A special inspection form is required for geotechnical approval of the drive -way
L__
subgrade prior to placing rock material as proposed; coordinate with engineering reviewer
for submittal of appropriate form.
The special inspection form has been included.
4. Reviewer has concern about directing runoff from all pervious areas to a point discharge
(end of swale) above a —26% slope and public walkway; revise plan as needed or provide
report/memo text addressing erosion and freezing concerns.
Up�Late:_ Not addressed adequately; through -curb discharges are not permitted. Remove
through -curb proposal and address as needed. A piped system will require connection to the
subsurface drainage system and the 48" main requires a Type 2 CB for connection.
The through -curb pipe has been replaced with a type 2 catch basin.
5. Show the limits of the rock around the chambers and provide dimensions between the two
nearest property lines and edge of infiltration facility; setback are applied to the limits of the
rock (infiltration occurs in full footprint of rock).
a. If utilities fall within required setbacks from the chamber system, provide additional
information (trench elevation vs chamber elevation) and/or additional improvements
(impervious liners, etc) to ensure infiltration water does not end up in utility trenches.
UJ Aate: Dimensions added to one location, but it appears the chamber is not parallel to the
property line and encroaches within 5' on the north side. Additionally it does not appear any
consideration of information regarding the water line within the 5' setback has been provided.
but water line appears to remain within setback. Revise alignment to maintain setback and
address utility trench concerns.
A storm easement has been added on lot 2 so that the chambers have required 5'
setback from the property line. A note was added to wrap water service trench with
impermeable layer.
8. Identify where the footing drains for the home are proposed to outlet.
Update: See note above regarding topographic information; ensure footing drains elevation
are adequate for positive fall as needed.
Footing drains now outlet to the French drain on Lot 1.
10. List or provide the required check dam spacing based on the design slopes.
jApd.ate: Not addressed. Check -dam detail removed, spacing not provided, and
drainage report states driveway grades should be below 3% to avoid checkdams; but plans
still show driveway over 3%. Provide check -dam information as needed and verify infiltration
function is maintained with reduced storage volume.
Check dams have been added to the plans.
Sincerely,
W���
Mark Keller, P.E.
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BEYLER