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United States Department of Agriculture

Agricultural Research Service

Title: Practical guidance for discharge and water quality data collection on small watersheds

Authors
item Harmel, Daren
item King, Kevin
item Haggard, Brian - UNIV OF ARKANSAS
item Wren, Daniel
item Sheridan, Joseph

Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 15, 2006
Publication Date: July 15, 2006
Citation: Harmel, R.D., King, K.W., Haggard, B.E., Wren, D.G., Sheridan, J.M. 2006. Practical guidance for discharge and water quality data collection on small watersheds. Transactions of the ASABE. 49(4):937-948.

Interpretive Summary: Many sampling projects have been initiated in recent years to determine the effectiveness of various best management practices in protecting water quality. Although guidelines for proper flow measurement are widely used, similar information for water quality sampling is not available. Thus, information on the design of water quality sampling projects is needed to make sound decisions regarding data collection resources, procedural alternatives, and project goals. The objective of this paper is to present the state-of-the-art methods for collection of discharge and water quality data to evaluate the water quality impacts of land management practices. Although many issues are involved in successful sampling projects, the following recommendations are generally applicable: 1) assemble a well-trained, on-call field staff willing to make frequent site visits, 2) commit adequate resources for equipment maintenance and repair, 3) establish reliable stage-discharge relationships for accurate discharge measurement, 4) take periodic manual grab samples to measure baseflow water quality, 5) use automated samplers to collect storm water quality samples, and 6) use composite sampling to reduce sample numbers.

Technical Abstract: Many sampling projects have been initiated in recent years to determine the effectiveness of various best management practices in protecting water quality. Although comprehensive references on discharge data collection have been published, similar guides to water quality sampling are not available. As a result, compilation of available information on the design of water quality sampling projects is needed so that proper decisions can be made regarding data collection resources, procedural alternatives, and project goals. Thus, the objective of this manuscript is to compile and present the state-of-the-art methodology for collection of discharge and water quality constituent data to support BMP evaluation in terms of water quality effects. Although many considerations are involved in establishing a successful sampling project, the following recommendations are generally applicable: 1) assemble a well-trained, on-call field staff willing to make frequent site visits, 2) commit adequate resources for equipment maintenance and repair, 3) establish reliable stage-discharge relationships for accurate discharge measurement, 4) use periodic manual grab sample collection with adequate frequency to characterize baseflow water quality, 5) use flow-interval or time-interval storm sampling with adequate frequency to characterize storm water quality, and 6) use composite sampling to manage sample numbers without substantial increases in uncertainty.

Last Modified: 7/31/2014
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