Streams: Sand and Gravel Problems | Missouri Department of ...
Sand and gravel removal should take place before March 15 and after June 15 to avoid harming spawning fish and their habitat. Keep fuel, oil and other wastes out of the stream. Do not remove gravel from riffles (shoals) because they prevent erosion of the stream bed. Riffles are very important to stream stability and are a major source of food ...