Water cannot readily soak into the ground, so it runs into the creek. With this increase in runoff, floods which may have occurred once in 25 years take place every 2 to 5 years. This increased frequency of flooding decreases the stability of stream banks and increases erosion and degradation of the stream channel. Pollutants such as pesticides, herbicides, metals, oil, grease, other hydrocarbons and sediment are moved into and down the stream. The Impacts Vegetation is uprooted due to the increased runoff.
Aquatic life is flushed downstream as water flow is increased.
Pollutants, toxic to aquatic life, enter the stream. Bottom dwelling plants, animals, and fish eggs are smothered by sediment. Deposition buries whole aquatic habitats. Trees are lost to clearing and to bank erosion. This reduces shade and increases temperatures, reducing the amount of oxygen and making the stream uninhabitable for many organisms other than algae.