Agricultural Impacts on Warmwater Streams Streams in the Chippewa drainage are physically degraded by agricultural practices. Agriculture affects bank stability, erosion, water temperature, primary productivity, stream flow, oxygen levels, amount of sunlight that is let in, and nutrients present in the water. Water quality can be improved by lowering average temperatures through shading of banks and channels. Re-establishment of vegetative cover secures banks, lowers stream velocities, traps suspended sediments, increases meander, promotes bank aggradation, and decreases down gradient erosion. These changes improve local and downstream water quality.
Agriculture contributes more than half the pollutants entering the nations rivers and lakes.
Agricultural practices contribute to the build up of sediment and the addition of nutrients and pesticides into streams and increases the salinity. Sediment from tilling leads to soil erosion and sediment build up. Sediment clouds the water, clogs the waterways, and prevents plants from photosynthesizing. Nutrients from fertilizers and manure contain nitrogen and phosphorus which promote algae growth. The water becomes cloudy, there is no photosynthesis, the algae die, and bacteria use oxygen to decompose the algae.