(c) GRN
As the rest of the nation takes great measures to remove dams, proposals to dam our
Southern creeks and rivers remain popular. More often than not, dam projects are
for "lake front" developments. These private developments alter
the health and quality of and inhibit public access to waterways which are
public resources. Dams should be assessed for their necessity and environmental impacts , social impacts , and alternatives need to be considered.
Environmental Impacts
- Alter natural stream flow patterns
- Change water temperatures
- Disturb and fragment habitat
- Alter sediment transport
- Block fish migration and spawning
- Impair water quality
- Increase water evaporation
- Increase predator risk
Social Impacts
- Alter the character, shape, and health of our natural heritage
- Effect recreational opportunities such as fishing, swimming, boating, hiking and bird watching
- Decrease business for local outfitters and canoe and kayak rental businesses
- Loss of public land and public resources like local or state parks and other green spaces
- Private property loss through eminent domain
- Economic impacts on downstream fisheries
- Lack
of control over flow levels leaves downstream communities vulnerable to
both diminished water supplies and increased flooding
- Water purification costs increase due to decreased water quality
- Maintenance costs and liability increase as dams age
- Dams for flood control can create a false sense of security and encourage development in vulnerable areas such as floodplains
Dam Alternatives
| Reason |
Alternatives
|
| Flood Control
|
- Reduce runoff through use of buffers, green space, and
permeable (porous) surfaces
- Move communities and individuals out of dangerous, flood
prone areas
- Flood proof or raise existing structures
- Restore river meanders thus increasing storage capacity
- Protect and restore local and upstream wetlands
|
| Irrigation |
- Better management practices such as assessing soil moisture,
measuring rainfall, irrigation scheduling, and mulching
- Use water efficient irrigation systems such as drip
irrigation
|
| Water Supply
|
- Water conservation
- Conservation water pricing
- Rain water catchment
- Recycle water
- Infiltration
galleries
- Replenish ground water supply through increase rainwater absorption
- Keep
development in balance with local water supply
|
Additional Resources
Beyond Dams: Options and Alternatives, American Rivers and International Rivers Network
Rivers at Risk: Dams and the future of freshwater ecosystems, World Wildlife Federation in cooperation with the World Resources Institute
|
