Don't Go With the Flow
kept the banks beat down and caused our problems.”
Murphy is also convinced of the value of vegetated stream corridors. “The riparian [or vegetated] corridor protects your banks not just from channel erosion, but also from water coming across your field,” he said.“That corridor stops a lot of erosion. I am the fourth generation of Murphys to own this land, but I don’t really own it—I am just the steward until I pass it on to my kids. By doing this, I can really see that stewardship becoming a reality.”
Conservation area projects
In addition to working with private landowners, Department employees have also stabilized eroding stream banks on conservation areas across the state. These projects improved the areas for all citizens that use and visit them, and they provided a proving ground for trying new techniques prior to suggesting them to landowners. Almost every technique recommended to landowners is first attempted on a conservation area.
Some of the first tree revetments that the Department constructed were built on Otter Creek, which runs through the Lamine River Conservation Area in Cooper County.
Beginning in 1989, Kent Korthas, area manager, and the Department’s Stream Unit put in five cedar tree revetments. The project helped stabilize a large segment of the creek, and information collected by the Stream Unit over the years was used at other sites.
The Department has also learned a lot about what doesn’t work. Some past attempts to control eroding stream banks have failed, and we have learned from those experiences. One important lesson learned is that every stream bank is influenced by the conditions of the watershed—both upstream and downstream. No part is isolated. Another is that erosion control is almost always costly. Preventing problems is far less expensive than repairing them.
The research continues
Despite many successes, the Department and private landowners are still looking for more options to stabilize eroding banks. There are limitations to the current techniques, and some only work on streams up to a certain size. Others can be cost-prohibitive for many landowners. In response, the Department is researching alternative techniques that are more universal and cost-effective.
The techniques being evaluated reduce costs by using more readily available materials and by changing designs to use less materials overall. Because we are using unproven materials in limited quantities, we are increasing the risk of failure compared to traditional techniques. The objective is to determine if significant cost and manpower savings can be achieved with an acceptable level of risk.
Due to the higher level of risk involved, the initial trials of these techniques will be conducted on Department lands rather than private properties.
Over the next two years, projects testing six different techniques will be installed at sites across Missouri. These projects will be monitored for several years across multiple high-flow events to learn as much as possible. The results will be used to improve our recommendations to landowners dealing with erosion problems.
Some erosion-control practices just don’t work. For example:
- Dumping junked cars, refrigerators, washing machines and other refuse into streams is not only unsightly and polluting, it does not stop erosion.
- Using heavy equipment to push gravel onto eroding stream banks does not work well because the flowing water easily washes the gravel-sized rocks away. The heavy equipment also disrupts the streambed, causing turbidity problems and destroying habitat.
For more information
If you are facing erosion problems on your property, contact your local Missouri Department of Conservation office for assistance (see a list of regional phone numbers).