By Hunter Slifka
Streams have the power to meander, move sediment, power industries, and destruct shorelines. With increasing flooding in recent years due to large rain events in the Midwest, streambanks in the region have been affected greatly. Programs and practices like shoreline protection and bank stabilization can combat erosion, protect streams and their banks, and improve wildlife habitat.
In 2018, the National Association of Conservation Districts (NACD), in partnership with the Natural Resources Conservation Service (NRCS) awarded funds through their technical assistance grants program to the Howard Soil and Water Conservation District (SWCD) in northeastern Iowa. Through these funds, Howard SWCD was able to assist local landowners with planning, design, land surveys and implementation of streambank management. In Howard County, 11 projects have been selected for bank stabilization practices, totaling over 6,000 feet of improved streambanks.
Streambank stabilization projects have straightforward construction schemes. On specified areas where erosion is present, the bank is sloped back to a 4:1 ratio. Using this slope ratio allows the stream to rise and fall within the corridor without creating more erosion issues. Large riprap rock is placed into the toe of the bank and up two feet above water level. The riprap is then covered with dirt and seeded down to a native seed mix or left bare, ensuring that the rocks will stay in place during flood events.
Projects within Howard County range from 90 feet to 1,550 feet long. These projects can be costly due to their scale, but with assistance from the Environmental Quality Incentives Program (EQIP), landowners are able to make improvements to stream quality. Streambank restoration projects have not only combatted erosion and improved water quality, they have also assisted in increasing local wildlife populations.
When local landowner Tim Huhe needed assistance with a streambank on his property, he turned to Howard SWCD. Huhe’s cattle grazed a pasture on his land that abutted a stream, but in some sections, the bank was eroded, undercut or destroyed. The cows would sometimes fall into the stream unaware, becoming injured or falling to their death. Howard SWCD conducted surveys of the land and created designs for a streambank stabilization project on Huhe’s property. The district completed its work within a week after beginning construction and now uses this project as an example county-wide. Through their partnership with local landowners, Howard SWCD has been able to utilize their technical assistance funds to improve water quality throughout the county, stabilizing streambanks across multiple watersheds.