HomeMy WebLinkAboutRS_Drainage Report_Crown Castle_210602_v1.pdfDUNCANSON
Company, Inc.
SURVEYING LAND PLANNING 145 SW 155th Street Suite 102
Seattle, Washington 98166 Phone 206.244.4141 Fax 206.244.4455 Web
www.duncansonco.
com CIVIL ENGINEERING
DCI 04168.
184 MEMO REPORT To: City
of Renton CED From:
Harold Duncanson, PE Date:
7/11/19 Subject: 2902
NE 12th Street Crown Castle
Site 831070—SUNSET
Drainage Memo Report This project involved development of a new wireless telecom
site. Improvements will include an antenna tower, rock surfaced equipment compound and
power/telco utility trenching. The equipment compound and an access connection comprise
the total new and/or replaced impervious surface, which is 1,996 SF. The clearing
limits for utility trenching, grading the equipment compound and construction
access are approximately 5,300 SF
of disturbed area. Also, this Project will not construct/modify a pipe/ditch 12-inches or larger,
nor does it receive runoff from such a system. The Site is not in a flood, erosion,
steep slope hazard or landslide hazard drainage area. The project is not a redevelopment project
of an existing
high use site. Based on these quantities and site characteristics, this Project falls below
the thresholds for drainage review (less than 2,000 SF new/replaced impervious and less than 7,
000 SF land disturbing activity) as identified in Section 1.1.1 of the Renton
Surface
Water Design Manual. As a matter of good practice, permeable ballast or other relatively clean,
crushed rock is specified for the equipment compound surfacing. Also, several ESC/
SWPPP measures are specified on the plans and were chosen in consideration of the lists in Section 1.2.
5.1 of the Renton Surface
Water Design Manual. Please call if you
have
any questions. RECEIVED
01/
08/2020