Stormwater and Erosion

Stormwater occurs when there are heavy rains and the amount of discharge in a river increases rapidly. An increase in stormwater runoff will only exacerbate poor conditions of the river banks (Miller). Statewide stormwater runoff guidelines are available to landowners and construction companies to help with erosion and sediment control. The main idea behind these guidelines is to encourage construction projects and adjacent landowners to channel any stormwater runoff into an adequate channel. An adequate channel is described as a waterway capable of receiving an increased amount of water in one particular event without causing major erosive damage and remaining within the confines of the natural channel. Construction sites are encouraged to channel stormwater and sediment runoff directly into an adequate channel through a pipe or sewer system (Recreation).

Stormwater runoff can cause problems in a waterway such as increased flooding events, massive bank erosion and an increase in pollutants entering the channel. Urban, man-made or intermittent streams can be modified to increase their carrying capacity for water and decrease the chance of flooding. Modifications made to waterways are known as rechanneling. This consists of widening, straightening or stabilizing banks and stream beds with man-made materials. Making these modifications to a natural, free flowing channel causes a great deal of erosion and can lead to a multitude of other problems, including local community member opposition (Recreation). As mentioned before, in the storm of 1969, the Tye River was quickly rechanneled by the Army Corps of Engineers. This was not perceived by the public as a proper reconstruction effort. Some local groups requested environmental assessments be done before rechanneling (Howard). The rechanneling was considered an act of desperation, according to local citizens. The effort to “re-build” the river ultimately failed and has caused major erosion events along the Tye River.


Understanding the natural tendencies of the river is important before commencing with any restoration effort. Dave Rosgen has worked in the field of hydrology for over 40 years and is considered to be an expert on river morphology. He has created his own stream classification method — the Rosgen method. This method describes a four level river assessment that is necessary before any restoration or rechanneling takes place (Rosgen). Often with rechanneling, the river is given a straight course. The velocity of a river is naturally fiercer in a straight run. This has many effects on the river. The bank is more rapidly eroded when the water has no twists and turns to slow it down. Also aquatic life finds it difficult to settle in a fast moving, straight stream (Loucks). Unfortunately, reversing a rechanneling project that runs a straight course is very difficult. The project would be long term and take the cooperation of the surrounding landowners, not to mention major sacrifices of land adjacent to the river. Some areas of the banks of the Tye are so heavily eroded the bank is at a 90 degree angle.