Surface runoff
Protecting or conserving critical habitat requires mitigation of anthropogenic effects. For most stream-dwelling fishes, altered stream flood hydrology from increased stormflow runoff is a major source of disturbance. While some flooding is natural, both the frequency and severity of damage may be exacerbated in areas with numerous impervious surfaces (roadways, parking lots, etc.). Surface runoff during storm events can significantly increase stream velocity and alter stream hydrology with channelization and excessive sediment deposits. Stormwater performance standards can set limits on the amount of precipitation that can leave a site as surface runoff, by infiltrating runoff into the soil.