HomeMy WebLinkAboutRS_Stormwater Description Letter_171005_v1
701 Dexter Avenue North, Suite 200 Seattle, Washington 98109 (206) 284-0860 Fax (206) 283-3206
October 4, 2017
Ms. Rohini Nair
Plan Reviewer
City of Renton
Department of Community & Economic Development
1055 South Grady Way
Renton, Washington 98057
SUBJECT: STORMWATER CONNECTION DESCRIPTION, PRV STATION 2
REPLACEMENT
SOOS CREEK WATER & SEWER DISTRICT, KING COUNTY,
WASHINGTON
G&O #17418.00
Dear Ms. Rohini:
Per direction from the Department of Community and Economic Development, this letter
is being submitted in place of a full TIR to address stormwater drainage requirements for
the above-referenced water utility replacement project.
The project will replace an aging pressure reducing valve (PRV) station located in the
roadway near the intersection of 103rd Avenue SE, SE 174th Street, and South 36th Place
with a new station in the right-of-way next to the road. The project will also replace
water main pipes, valves, and fittings associated with the connections to the station.
Drain lines from the proposed PRV station will connect to a proposed catch basin and
from there to an existing City of Renton stormwater catch basin in the intersection of
103rd Avenue SE, SE 174th Street and South 36th Place. The project does not create new
impervious area or change the surface drainage characteristics of the site. All disturbed
impervious and landscaped areas are to be restored to preconstruction conditions. During
construction, temporary erosion and sediment control (TESC) measures will be in place
to prevent discharge of sediment to the stormwater system.
The new catch basin is intended for discharge of pressure relief water from the PRV
station. No upstream drainage area is to be collected by the catch basin and it will be
installed with the rim above grade to prevent surface runoff from entering. A 4-inch
drain line from a sump in the station to the proposed catch basin will drain any water that
may collect in the station from the pressure relief valves or potentially leak into the
Ms. Rohini Nair
October 4, 2017
Page 2
station. The drain pipe from the new catch basin will connect to the existing stormwater
catch basin in the intersection.
Please contact me if you have any questions or need additional clarification regarding any
elements of the design.
Sincerely,
GRAY & OSBORNE, INC.
Tracy Winjum, P.E.
TW/hh
cc: Mr. Ken Van Den Bergh, Utilities Superintendent, Soos Creek Water & Sewer Dist.