FLOOD06408

• County: Weld
• Community: Windsor
• Stream Name: Big Thompson/South Platte/Cach la Poudre
• Basin: South Platte
• Title: Drainage Basins and Areas of Past Flooding in the Winsor Area, Colorado
• Date: 1/1/1971
• Prepared For: University of Colorado
• Prepared By: James Paul Walsh, Jr.
• Floodplain - Doc Type: Flood Documentation Report

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GENERAL GEOLOGY AND GEOGRAPHY

The Windsor 'area is flat and gently rolling cou~try within

the South Platte River basin, The Big Thompson and Cache la Poudre

Rivers flow eastward across the area"toward their confluences with

the South Platte River.

The climate of the area is semi-arid with an average annuel

precipitation of fourteen inches at Fort Collins, The natural

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vegetation is mixed ,grassland and shrub plant communities with an

occasional Ponderosa pine' and Ro'cky Hountain juniper. CottoUlwods

is agriculture and numerous reservoirs and canals provide the neces-

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line the banks of streams throughout,the area. The major land use

sary wat~r to make it pas sible in the dry climate.

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The important geologic formations exposed in the' area' are

Upper Cretaceo~s bedrock and Quaternary surficial deposits. Bedrock

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consists of the Niobrara Formation, Pierre Shale, Fox Hills Sandstone

and La,.,~mie Formation, all of which dip steeply to the east. The

surfici&~ deposits are largely pediment and valley deposits, Pedi-

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ment deposits consist of arkosic sand, gravel and red c,lay, Valley

deposits are flood plain deposits of sand, silt and clay and terrace

deposits of arkosic gravel and sand (HerShey and Schneider, 1972).

Hoderately deep loam soils dominate the flat and gently roll-

ing upland terrain. The rarge valley bottoms contain dominantly

alluvial soils of loams a,nd clay loams (U. S, Dept" of Agri., Soil

Conserv. Service, 1970, p, 2).

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