Stream Restoration

Tree roots and short pasture grasses are not dense or diverse enough to prevent this streambank from rapidly eroding.

Ecological restorations use earthworks and revegetation to permanently hold streambanks in place. These restored riparian zones are rich in wildlife habitat and filter out sediment and pollutants from the water.

Throughout Iowa, streambanks are rapidly eroding due to the loss of diverse, deep-rooted perennials, recently expanded use of agricultural drainage tile, increasingly heavy rainfall events, and a legacy of stream straightening and other faulty stabilization techniques.

At Prudenterra, we use evidence-based, ecological restoration methods for a lasting solution to managing streambank erosion.

Ecological Stream Restoration

When a stream is degraded, the first step is an in-depth evaluation called a Stream Restoration Review. It includes a subwatershed analysis with remote sensing technology, a site visit, and restoration recommendations. Prior to revegetation, the streambank must be resloped with earthworks or cedar revetments. Then, the soil is held in place with deep-rooted perennials including native prairie, shrubs, and trees.

This Iowa stream was recently resloped with cedar revetments, and revegetated with diverse trees, shrubs, and grasses.

The causes of erosion are unique to each landscape and land use. Sometimes uphill or upstream water flow patterns, tile infrastructure problems or livestock management must be addressed before the problem can be fully solved. In some cases, streams that have been straightened must be re-meandered to slow the cutting flow of water.

An important component of ensuring that the soil will stay in place is to maintain a wide buffer of deep rooted, native vegetation. Buffers not only prevent future streambank erosion, but filter water that flows over the land. When drainage tile lines flow through a buffer to filter out nitrates and other pollutants, it is called a saturated buffer. Vegetative buffers create a rich habitat for wildlife, and improve opportunities for recreation such as fishing, hunting for game and wild edibles, swimming and hiking.