Ditch Records and Policy Considerations

The primary purpose of this project was to compile and organize records available from Hennepin and Carver Counties; such as construction documentation, surveys and benefited parcel information; for the county/judicial ditch system in Minnehaha Creek Watershed District. A secondary purpose was to convert records into electronic form. This project is a first step to enable discussions of policy and management strategies for county and judicial ditches. A 1992 ditch evaluation was completed by MCWD but that project was very limited in scope and did not thoroughly locate available records. The 1992 evaluation focused solely on ditch maintenance issues. System mapping, construction information and benefited parcel information were not part of the 1992 evaluation. The District's Operations and Maintenance Manual was completed in 2000. The plan recognizes the existence of ditches and treats them as an O&M obligation. The 2000 O&M plan specifies that a ditch inspection and report should be completed on a five-year interval, beginning in 2001. Ditch inspections have not been budgeted through 2003. Several related activities are currently being undertaken by MCWD that create a need to develop a management policy regarding ditches. These are: • NPDES Phase II requirements will go into effect at the end of 2002 and will involve regulation of ditch systems as storm water conveyances. • Many of the primary streams in the District are also county/judicial ditches. MCWD has begun an assessment of primary streams and will work to develop stream management strategies. Most streams are also county or judicial ditches and desirable ecological management strategies for streams may conflict with maintenance of ditches as a public drainage system. • Ditches are the primary conveyance of runoff, nutrients, and pollutants into Lake Minnetonka bays. Ongoing H&H modeling of the District may result in recommendations that could affect ditch alignment, function and/or hydraulic performance. • The existing O&M manual for the District recognizes county/judicial ditches as a maintenance issue and requires inspections of the ditch system every 5 years. It is recommended that a comprehensive ditch inspection be budgeted for 2004. • Permit applications may involve land development that affects county/judicial ditches. There is no discussion of county/judicial ditch standards or requirements in existing rules. • MCWD is evaluating whether wetland management can be a means of reducing nutrient and pollutant loading to Jennings Bay. That evaluation needs to address management impacts on ditch alignment, function, and hydraulic performance. • Some county/judicial ditches are functioning as city stormsewers. The MCWD needs to determine if these ditches should be transferred to the cities. In order to begin developing a coherent and coordinated policy that takes many (possibly competing) activities into account, the basic existing information about the ditches needed to be compiled and organized. This report and the accompanying electronic database provides the basis for the Managers to begin developing ditch policies. Information stated in this report on the impact of a ditch on wetland size and the timing of such impacts is for the purpose of this report and is not intended to reflect an examination for the purpose of regulatory discussion under the Wetland Conservation Act, protected waters statute, or §404.