Agriculture

Agricultural Impacts on Stream Water Quality

Agricultural practices can negatively impact water quality on streams near farms. Improper agriculture practices can lead to increased levels of nutrients, coliform, sediment, and chemicals.

Nutrients

    • Animal waste can lead to an increase in Nitrates and Phosphates in the water. The nutrients can enter the water directly or runoff from pastures.
    • Why is this a problem?
        • An increase in nutrient load can lead to eutrophication of a body of water. Eutrophication occurs in a body of water when high nutrient concentrations lead to algal blooms, which can lead to plant death due to lack of sunlight and oxygen.

Coliform

    • Animal waste can introduce fecal coliform, which is a threat to public health.

Sediment

    • Grazing can increase sediment load due to disturbance of pastureland.
    • Improper crop rotation, tillage, and lack of cover crops also all can lead to an increase of erosion, which leads to an increase of sediment load in a stream.
    • Increased sediment in a stream can inhibit macroinvertebrates and fish from breathing through their gills. It can also make purification for drinking water difficult.

Chemicals

    • When pesticides, herbicides, and fertilizers are applied to crops, they often are carried away by rainfall to nearby streams.