Interstate-94 over Portage Creek in Kalamazoo County.

Streambank erosion can contribute phosphorus to surface waters. Bank erosion can be pronounced at road-stream crossings, particularly if culverts are undersized. Undersized culverts increase stream velocities, promoting scouring on the downstream side. The MESBOA technique is a method of properly sizing and orienting culverts, based on the stream's physical characteristics.

Road-stream crossings have been identified as a source of sedimentation in the St. Joseph River Watershed. A subcommittee (as a part of a current Section 319 project) identified procedures for quantifying sediment loading from road-stream crossings. A method to track those nonpoint sources was considered a valuable objective for the project. An MDEQ intern is conducting road-stream crossing surveys in the Kalamazoo River Watershed using the quantification form below.

Erosion at road-stream crossings, and along streambanks in general, can be quantified using the lateral recession rate method. The length and height of the site of erosion are measured in the field. The lateral recession is then estimated based on the severity of the erosion. These parameters are multiplied to yield a volume of soil lost annually. The soil type is used to estimate a soil density, so that volume can be converted to mass of sediment lost. The average phosphorus content in Kalamazoo River soils (0.8 lb P/ton soil) was used to calculate the annual phosphorus loading from the streambank sites surveyed in 2003. The links below lead to forms and instructions for quantifying streambank erosion.

Erosion Quantification Resources to Download:

• Erosion quantification form and instructions:
  • PDF
• Erosion quantification field forms (three to a page)
  • Microsoft Word
• Calculator spreadsheet
  • Excel

   

Related Forms

• MDEQ Road-Stream Crossing Form
• Habitat quality scoring
• Erosion scoring (quantification plus physical parameter scoring)

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