WSP01414

• File Number: 8449.918
• Description: South Platte Projects
• State: CO
• Basin: South Platte
• Date: 8/1/1982
• Author: CWCB
• Title: South Platte River Basin Assessment Report
• Water Supply Pro - Doc Type: Publication

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Consultants, Inc. and Toups Corporation, 1974). In the Poudre Canyon,

decreased flows due to municipal water supply and agricultural diversions

generally result in increased water quality concentrations. At Greeley,

ammonia levels and average dissolved solids concentrations of the Cache 1a

Poudre River increase substantially, indicating relative contributions of

agricultural pollution discharges and the influence of lithology and saline

shale soils (Larimer-Weld Regional COuncil of Governments and Toups

Corporation, 19781 Colorado Department of Health, 1980).

Agricultural return flows and runoff from cattle feed lots have affected

water of the alluvial aquifer near Kersey (Borman, 1981). Moreover,

relatively large concentrations of nutrients (nitrogen or phosphorous) have

been measured in the SOuth Platte River between Denver and Kersey (Colorado

Department of Health, 1980), as well as in the adjacent alluvial aquifer.

These conditions probably are aggravated by agricultural practices in the

area.

Most concerns regarding water quality in the downstream reaches of the

SOuth Platte River are the effects of agricultural return flows and

municipal wastewater discharges. Mean annual dissolved solids

concentrations in the lower reaches of the SOuth Platte River consistently

exceed 1000 mg/l (Figure 9). Mean sulfate concentrations increase from 500

to nearly 700 mg/l in a downstream direction between Kersey and Julesburg

(Table 11) (Gaydos, 1980; Colorado Department of Health, 1980). Large

concentrations of dissolved solids and sulfates pose potential problems for

the use of downstream SOuth Platte River water for municipal and domestic

water supplies (COlorado Department of Health, 1980).

A water quality characterization of the SOuth Platte River alluvial aquifer

system was made by the COlorado Westwide Study Team (U.S. Department of the

Interior, 1974), Engineering COnsultants, Inc. and Toups Corporation

(1974), and Hurr; Schneider, and Minges (1975). Water derived from the

dune sand generally is acceptable in water quality for most uses because

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