WSP06933

• File Number: 8272.500
• Description: Colorado River Basin Salinity Control - Colo Dept of Public Health - WQCC and WQCD
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 11/1/1989
• Author: WQCD
• Title: Colorado Nonpoint Assessment Report - November 1989
• Water Supply Pro - Doc Type: Report/Study

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Bear Creek Lake trophic status varies between eutrophic and hypertrophic. The

dissolved oxygen values in the bottom water during the summer growing season

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drop to zero.. This greatly reduces available aquatic habitat and stresses

biological components. The algal blooms affect the recreational and water

supply beneficial uses. The watershed experiences extensive erosion in ,the

spring runoff period. The.sediment load effects the recreational and aquatic

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life beneficial uses.

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There is a significant sediment and nutrient loading, along with a periodic

higher loading of heavy metals, discharged into Bear Creek Lake from both

Turkey and Bea~ Creeks. Almost 99% of the sediment load transported to the

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reservoir as suspended solids on an annual basis is from nonpoint 'sources.

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This load exceeds 1.2 million pounds of suspended material.. There is also a

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large bedload transport to the reservoir as evident by the~i~ration of the
sedi~ent deltas into the reservoir. Approximately 58% of the phosphorus
loading and 73% of the nitrogen loading on an annusl basis is from nonpo.int

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sources. These nonpointsources are associated with urban and 'construction

activities with some contributions from agriculture and pasture management

practices, and hydrologic modifications. There has been some limitedminin~

activities which could account for the arsenic and radioactive materials

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measured in the lake and watershed.

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