Graphic representation of the two-stage ditch design.
Elevation & Width
Graph representing the size of a possible two-stage ditch, in feet.
Prior to European settlement, Indiana was covered primarily by deciduous forests, wetlands and grasslands. Today the bulk of the state is dominated by row-crop agricultural lands. To make this land more productive for farming, streams have been ditched, fields tiled and wetlands drained such that water is quickly removed from the land. This has drastically altered the hydrology of our streams and rivers, creating “flashy” ecological systems. Bank erosion, scouring, and flooding are good indicators that there is problem with how the water is drained from the soil.
There is no simple solution to address altered hydrology. However, one promising innovation is the two-stage ditch. This design mimics a more natural stream channel when compared to the conventional channels found in most managed ditches. What makes this ditch unique is the low flow channel and corresponding bench that allows for bank overflows to occur within the confines of the ditch. The benches within a two-stage ditch function more like stream-side floodplains, slowing the flow of water and reducing bank scouring.
The Nature Conservancy believes that wide-scale implementation of the two-stage ditch can be part of a viable long-term solution to benefit local and state-wide water quality. With the funding we have received from the Indiana Department of Environmental Management (IDEM) Section 319 Program, the Chapter can promote the usage of this ground-breaking design in the Wabash River Watershed.
Education and outreach effort will be undertaken state-wide. The Conservancy will host workshops, presentations and field days targeting county surveyors, watershed managers and private landowners to increase general understanding of two-stage practices. These gatherings will provide information including design, construction and maintenance costs and proof of the ecological performance of the ditch. The Conservancy hopes that these outreach efforts will increase interest in the practice, translating to implementation in the future. Our hope is that the two-stage design will be an integrated solution that will positively impact water quality and aquatic habitat across the state.
For More Information
Learn more about the two stage ditch design via Ohio State University's Natural Channel Design pages. Links to various modeling software and other helpful tools are available as well.
The Ohio Department of Natural Resources and The Ohio State University have also developed an educational tool called STREAMS Modules. Each module discusses various themes including basic stream knowledge, more advanced channel information as well as river evaluation, assessment and monitoring techniques.
The Conservancy would also like to acknowledge both Ohio State University and the University of Notre Dame for their monitoring efforts that is developing and has developed the science that guides the Two-stage Ditch Practice.
Conservancy's two-stage ditch design presentations:
*This project has been funded wholly or in part by the United States Environmental Protection Agency under assistance agreement C997548210 to the Indiana Department of Environmental Management. The contents of this document do not necessarily reflect the views and policies of the Environmental Protection Agency, nor does mention of trade names or commercial products constitute endorsement or recommendation for use.