Agricultural Drainage Channels

FrontThroughout much of the North Central Region of the United States streams have been modified to enhance surface and subsurface drainage of the adjacent landscape for reliable, economically viable production of agricultural commodities (Figure 1).

These modifications generally involve lowering of the streambed or a wetland slough to provide freeboard for subsurface drainage systems, which are installed below agricultural fields, and enlargement of channels to increase downstream conveyance capacity.

Historically, agricultural drainage channel designs have a simplified form, disconnected floodplains, little diversity and dynamism, and management regimes that prevent system recovery through natural processes. According to the Census of Agriculture, government agencies reported over 77,500 total miles of streams had been converted to agricultural ditches in Indiana, Michigan, Minnesota, and Ohio alone through official legal mechanisms.

Our experience with agricultural drainage in the Midwest suggests that many of the modifications made to streams and regular maintenance activities are done by private landowners that would not be captured in Census estimates. Therefore, the Census estimates are likely an underestimation of the true extent of modified agricultural ditches in the region and in some watersheds ditches may form 80% or more of the entire length of the drainage network (Blann et al., 2009).

While ditches successfully drain the soil profile, their deviation from natural conditions drives the loss of ecological function and services, such as water purification, downstream flood control, and the provision of habitat and biodiversity.  Reconnecting the channel to its' original floodplain is not practical as the adjacent land use is dependent upon the drainage function the channel provides.  However, water quality problems associated with agriculture and the deleterious ecological, fluvial, and economic impacts of ditch maintenance have forced a collective rethinking of drainage management strategies in the North Central Region that provide drainage, but also enhances other imporant ecological services.

This website provides information on ditch managment options available to landowners. The goal of this website is to increase Ohio’s and the North Central Region's capacity to understand agricultural drainage practices, implement alternative drainage techniques, educate farmers and decision-makers about ditch management options, and provide case study examples of approaches that promote agricultural productivity while reducing nutrient and sediment exports and expanding the ecological benefits of agricultural drainage ditches.