Wildhorse
Riverworks

Wildhorse Riverworks, Inc. (WRI) personnel surveyed, designed, and provided construction oversight for streambank rehabilitation of more than 68,849 feet of the Little Blue River in Washington and Marshall Counties, in Kansas. The project shown here is one of 51 projects involving 40 landowners. Collectively, the projects span over 13 miles of riverbank and established more than 158 acres of riparian habitat.  The landowners requested assistance to reduce the high streambank erosion rates and loss of valuable farmland. The State wished to assist the landowners and reduce sediment volumes interring Tuttle Creek Reservoir. As a condition for obtaining cost share assistance from the State, landowners were required to enroll a 66 or 100 foot wide strip of land adjacent to the stream into the U.S. Department of Agriculture’s Continuous Conservation Reserve Program (CCRP).

​

​

​

WRI began surveying problem sites the fall of 1999. The site shown above was surveyed in March 2000. By August 2001, lateral bank erosion moved the left streambank over 200 feet and increased the eroding streambank length from 1,700 feet to 2,100 feet. WRI staff installed horizontal bar erosion monitor rods on 12 sites in April 2000. These rods were 4 or 6 feet long and driven into the streambank until the ends were flush with the soil. When the same sites were visited in May of 2000, the horizontal rods were all missing. This means that a minimum of 4 feet of streambank was lost to erosion in 1 month on all 12 sites. On 1 of the 12 sites, vertical pins were placed 29.1 feet and 28 feet (respectively) from the top of streambank. When this site was visited 1 month later, only 1 pin was still existing and only 8 feet remained between the pin and streambank.

​

​

​

​

Based on information from detailed topographic surveys and geomorphic assessment, WRI recommended installing bendway weirs to reduce streambank erosion.

 

Bendway weirs reduce streambank erosion by re-directing flows and reducing stress in the near bank region. WRI used the weirs to reduce the stream’s width / depth ratio and move the thalweg (deepest part of channel) from the near bank region and induce deposition along the previously eroding streambank toe.

 

 

In January 2002, the bendway weirs were constructed and the vertical streambanks were reshaped to a 3H:1V slope. The slope was seeded with a cover crop of oats and mulched with native prairie hay. In the early April 2003, the banks and buffer were planted with a mixture of native tree and shrub species along with a native grass filter strip.

 

The goal of this project was to reduce streambank erosion and improve aquatic and terrestrial habitat. The use of bendway weirs worked with the stream’s natural tendencies to move the stream toward a more naturally stable condition.