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Quality of surface water before implementation of a flood-control project in Chaska, Minnesota

Water-Resources Investigations Report 81-83

Prepared in cooperation with the U.S. Army Corps of Engineers
By:

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Abstract

Samples were collected for 1 year from East Creek, Chaska Creek, and Courthouse Lake in Chaska, Minnesota, to determine the water quality before implementation of a flood-control project proposed by the U.S. Army Corps of Engineers. The creeks had similar water-quality characteristics. Data indicate that ground water may be the primary source of dissolved solids, sulfate, chloride, and chromium in the creeks. The pesticides alachlor, atrazine, simazine, and 2,4-D were found in water samples from both creeks but were well below the lethal concentrations for fish. Courthouse Lake, a 57-foot-deep stream-trout lake, had a mean summer trophic-state index of 35. Phytoplankton populations varied seasonally, and blue-green algae were predominant only in late summer. The algal-pollution index was highest in late summer, but did not provide evidence of high organic pollution. The apparently successful recovery of Courthouse Lake from past inundations by Minnesota River floodwaters having total phosphorus concentrations as high as 0.66 milligram per liter suggests that the lake, in time, will also recover from the added runoff expected as a result of implementing the flood-control project. The runoff could temporarily raise the total phosphorus concentration in the lake from 0.03 to 0.12 milligram per liter and raise the spring trophic-state index from 49 to 69.

Study Area

Additional publication details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Quality of surface water before implementation of a flood-control project in Chaska, Minnesota
Series title:
Water-Resources Investigations Report
Series number:
81-83
Year Published:
1981
Language:
English
Publisher:
U.S. Geological Survey
Publisher location:
St. Paul, MN
Contributing office(s):
Minnesota Water Science Center
Description:
iv, 53 p.
Country:
United States
State:
Minnesota
City:
Chasta
Online Only (Y/N):
N
Additional Online Files (Y/N):
N