Dredging Evaluation of Ditch 6 (South Branch of 10-mile) WCR_09_09


The purpose of this project is to evaluate dredging practices on Ditch 6 in the Portage County Drainage District. This ditch is a coldwater trout stream with excellent reproduction. The Drainage district is excavating/dredging as part of maintenance. There is some evidence that this dredging is having adverse impacts. No studies have been done to evaluate the immediate impact dredging has on salmonids and water quality.


The objective of this study is to evaluate the impact of dredging on a coldwater fishery. Field tests show DO concentrations below the lethal limit for salmonids downstream of active dredging. Suspended solids are extremely high, but have never been properly evaluated. Along with water quality, flow characterisitcs will be evaluated to determine the difference in flow before and after dredging. The net change in flow has not been evaluated to see if in fact, dredging increases flow.


1) Number of sample sites associated with the project 2 sites with 4 samples each. 2) Number of sampling events associated with project. 8 3) Estimated date when sample collection will be complete. TBD according to dredging activities of District 4) Estimated date when all data will be entered into appropriate database. Immediately, as lab results are completed they will be entered into SWIMS. 5) Estimated date when final report will be complete. June 2009

QA Measures

Run Project Summary Report

TMDL/303d Projects
Identify Impaired Waters
Reports and Documents
This is for Ditch 6, disregard "Ditch 4" name on spreadsheet title.
Activities & Recommendations
Monitor Targeted Area
Dredging evaluation