- Comes in pulses from towns (when it rains)
- Can contain high concentrations of salt
Before and After Urbanization
- Before Urbanization: Evaporation – 40%, Surface Runoff – 10%, Groundwater – 50%
- After Urbanization: Evaporation - 25%, Surface Runoff - 43%, Groundwater - 32%
How to Control Flooding (general)
- Slow down water flow
- Increase absorbtion
Reducing flooding and damage from flooding:
- Don't remove wetlands
- Don't remove upland vegetation
- Don't remove streamside vegetation
- Don't channelize streams
- Don't build in floodplains
- Occurs where you irrigate arid areas
- Brings salt out of the gound
- Forms salt pans
- Vegetation doesn't recover in this area
- Supplies water to about 20% of the area.
- Recharge rate extremely low.
- Most of the recharge has come from ice melt from the last iceage.
- Conversion of land to corn should increase water use.
- (Eastern SD)
- This region is the biggest region for the production of waterfowl for the country.
- Has suffered a reduction of about 50% of ponds and 50% of water fowl populations.
- The ponds are disappearing because of drought.
Point vs Non-Point Pollution
- EPA Regulations Point-Source Pollution. (Can be followed back to a source.)
- Most of the pollution in the US and worldwide is from non-point sources. (Running across the land, carrying pollutants.)
- Non-Point are more common.