Beem Ditch
GREAT LAKES
REGION
2013
Contacts
Dan Mecklenburg, Division of Soil and Water Resources Ohio Department of Natural Resources, Email: [email protected]
Jon Witter, Jessica D’Ambrosio, Andy Ward, Dept. of Food, Agricultural and Biological Eng. The Ohio State University, Email: [email protected]
Project Overview
• Located in Franklin County, Ohio. Latitude: 40.054 º N, Longitude: 82.862 º W.
• The project was initiated in fall 2005 to relocate a stream to accommodate a commercial development.
The site was designed by the consulting firm EMH&T.
• The contributing drainage area is 0.45-square miles and the predicted two year peak discharge is 238-ft3/sec.
Estimated stream power for the reach is 40 lbs/s/ft.
• The constructed surface had a slope of 0.27%, a length of 500-ft, and was 38-ft wide.
Total area of the flat constructed surface was 0.4-acres.
• Reference channels in the region with this drainage area tend to be about 11.2-ft wide and 1.5-ft deep.
The constructed surface width is 3.4 times wider than the reference channel bankfull width.
• The channel, 7-yrs after construction, averaged 5.6-ft wide. By this time the floodplain had aggraded 5.5-inches,
or 0.8-inches per year. That is about 4.4% of the reference channel floodplain height per year.
• The difference between the constructed surface and the eventual height of the floodplain is in effect a void or sink
gradually filling with sediment, plant material, and nutrients. The initial sink volume was 822 cubic yards.
During the first 7 years, 201 cubic yards of material have accumulated.
At Beem Ditch, the constructed surface was over-excavated (~1 ft) then
brought up to grade with topsoil. For several weeks prior to routing
flows through the channel, a stabilization seed mix was allowed to
establish. By the following spring, the seeded vegetation was no longer
present; however, a preferential flow path had formed amid fluvial
deposits. By Aug 2006, robust grasses had established forming
vegetated floodplains, which flanked a defined channel. Over the next
two years, the bed scoured as much as 16-inches on portions of the site.
Fortunately, riffle formation along the reach maintained the grade and
scour resulted in the formation of pools and did not lead to incision. The
source of coarse riffle deposits that formed must be in part derived from
the scour pools that formed; however, we suspect that some material
was supplied from the catchment and drainage network despite it
being mostly enclosed storm drains. Over time, vegetation transitioned
between wetland species and grasses, but more recently has shifted
to pioneering tree species as the floodplain continues to aggrade.
Additional tree species were planted three years after construction
as site conditions become conducive to support those species.
Beem Ditch
Before receiving flow Aug 2005
0.6 yr May 2006
0.8 yr Jul 2006
1.7 yr Jun 2007
3.7 yr Jun 2009
6.8 yr Jul 2012
7.7 years June 2013
http://greatlakeswater.uwex.edu/
This material is based upon work supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, National Integrated Water Quality Program, under Agreement No. 2008-51130-04751. Any opinions, findings,
conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture. USDA is an equal opportunity provider and employer, and
prohibits discrimination in all its programs and activities on the basis of race, color, national origin, sex, religion, age, disability, political beliefs, sexual orientation, and marital or family status.