HomeMy WebLinkAboutPN_Project_Narrative_20170403_v11
Clark Close
From:Cooley, Linda <CooleyL@wsdot.wa.gov>
Sent:Monday, April 03, 2017 4:38 PM
To:Clark Close
Cc:Vicki Grover; Hanson, Allison (Consultant)
Subject:LUA 15-000522, CAR Permit Modification Request
Attachments:NW Haul Route.pdf
I-450 SR 167 Direct Connector Project
Reference LUA 15-000522, CAR
City of Renton Critical Area Permit
Dear Clark,
Please modify our City of Renton Critical Areas Permit LUA15-000522 issued December 4, 2015 to allow
additional temporary wetland buffer impacts. The modification is necessary to allow trucks to access the
existing haul road from the hillslope excavation area near the northbound on-ramp to I-405 from northbound SR
167. Installation of the temporary access road will result in an additional 5,321 of temporary wetland buffer
impact. WSDOT’s Design-Build Contractor, Atkinson Construction will extend the haul road along the east
side of Rolling Hills Creek. The temporary buffer impacts are needed to extend the existing quarry spall haul
road. This will allow trucks to haul fill material and large woody debris (LWD) from the Talbot Hill slope
excavation work area directly to the Rolling Hills Creek channel restoration area and the SR 167 fill areas.
Please see the attached sketches of the proposed change. The area is currently dominated by blackberries with
alder and big leaf maples trees.
After the roadway work and the new channel are constructed, we take the following steps to restore the buffer.
· Removal of any haul road surfacing (e.g. hog fuel) and decompaction of haul road by ripping to 18”
min. depth.
· Proposed restoration planting areas not impacted by construction traffic to be decompacted to 12”
min. depth.
· Proposed restoration planting areas to receive 4” fine compost amendment incorporated into
decompacted existing soil to 10” depth. As an alternative, 12” depth import topsoil may be used. (per
Tech. Requirement 2.15.4.14)
· Planting areas to be topped with 3” depth bark or wood chip mulch. (per Tech. Requirement
2.15.4.18)
· Proposed restoration planting to consist of a native tree and shrub mix suited to upland, similar to
Corridor Tree Mix (minus the Norway Maple) and Corridor Shrub Mix shown on p. 30 of Appendix
L2. Tree spacing to be 12’ o.c., and shrub spacing to be 4’ o.c.
· The new plants will receive 5 years of plant establishment maintenance to ensure success of the
restoration.
Please let me know if you have questions or require further information to modify or update our permit.
Thank you.
Sincerely,
Linda Cooley
2
Environmental Permit/Compliance Lead
WSDOT NWR Design Build Office
425-456-8586
206-769-7481