SWPPP 111.112.pdf

CHAMBERS CREEK WATERSHED

SITE 111 & 112 FLOODWATER RETARDING STRUCTURE

STORM WATER POLLUTION PREVENTION PLAN

SITE DESCRIPTION

Project Name and Location:

Chambers Creek, Site No. 111 & 112, is located approximately 1 mile east of Nash, Ellis County, Texas.

Latitude: 32o 16’ 48” N Longitude: 96o 48’ 10” W

Owner Name and Address: (Permanent)

Ellis-Prairie Soil and Water Conservation District 1822 FM 66, Suite 102 Waxahachie, Texas 75167

Owner Name and Address: (During Construction)

USDA, Natural Resources Conservation Service 101 South Main Temple, Texas 76501

DESCRIPTION

This project will consist of repairing the upstream slope and east outlet channel of Chambers Creek, Site 111 & 112 floodwater detention dam built in 1960. The existing structure consists of a 28” principal spillway on Site 111 (the east side) and a 22” principal spillway on Site 112 (the west side) and 450’ wide auxiliary spillway. The dam is approximately 3,822 feet long and 31 feet high. The repair will involve excavating the upstream slope; reconstructing the upstream slope with compacted lime-treated earthfill and armoring the approximately 50 feet of the outlet channel immediately downstream of Site 111 plunge basin and approximately 100 feet of gully at the downstream toe of Site 112 with geotextile and rock riprap.

The repair will require the estimated quantities of 36,000 cubic yards of total excavation;

1,200 tons of lime; 23,000 cubic yards of lime-treated earthfill; 425 tons of rock riprap;

455 square yards of geotextile; 40,300 square yards of topsoil; 4,600 feet of sediment fence and 6,500 linear feet of barbed wire fence.

Soil disturbing activities will include: clearing and grubbing; stripping the lime processing area and the embankment; constructing the access; processing removed embankment soils with lime; excavating the upstream slope of the embankment; placing lime-treated earthfill on the embankment; excavating and placing rock riprap in the Site 111 outlet channel and the gully at the downstream toe of Site 112; stripping and excavating of borrow areas; disposing of waste materials; and grading, shaping, and

AG-7442-S-09-0042