Of the more than 80,000 dams listed by the federal government, more than 26,000 pose high or significant safety hazards. Many no longer serve any real purpose. All have limited life spans. Only about 1,750 produce hydropower, according to the National Hydropower Association.
In many cases, the benefits that dams have historically provided — for water use, flood control and electricity — can now be met more effectively without continuing to choke entire watersheds.
Dams degrade water quality, block the movement of nutrients and sediment, destroy fish and wildlife habitats, damage coastal estuaries and in some cases rob surrounding forests of nitrogen. Reservoirs can also be significant sources of greenhouse gas emissions.
Put simply, many dams have high environmental costs that outweigh their value. Removing them is the only sensible answer. And taking them down can often make economic sense as well. The River Alliance of Wisconsin estimates that removing dams in that state is three to five times less expensive than repairing them.
The message has been slowly spreading around the country. More and more communities and states have reclaimed rivers lost to jackhammers and concrete. Last year, 51 dams in 18 states were taken down, restoring more than 500 miles of streams, according to the group American Rivers. Nearly 850 have been removed in the last 20 years, and nearly 1,150 since 1912.
But the work is far from done. I was disappointed to see the Energy Department release a report last week on the potential to develop new “sustainable” hydroelectric dams on rivers and streams across the country. The report follows President Obama’s signing of two laws last year to encourage small hydro projects and revive nonproducing dams.
New dams are a bad idea. We’ve glorified them for decades, but our pride in building these engineering marvels has often blinded us to the environmental damage they cause. The consequences run the length of the river and beyond. Our many complex attempts to work around these obstacles would make Rube Goldberg proud. Interventions like fish elevators and trap-and-haul programs that truck fish around impoundments don’t lead to true recovery for wild fish populations or reverse the other environmental problems caused by blocking a river’s flow.
But we do know that removing dams brings streams and rivers back to life and replenishes our degraded aquifers.
by Yvon Chouinard, NY Times | Read more:
Image:Marta Monteiro
In many cases, the benefits that dams have historically provided — for water use, flood control and electricity — can now be met more effectively without continuing to choke entire watersheds.
Dams degrade water quality, block the movement of nutrients and sediment, destroy fish and wildlife habitats, damage coastal estuaries and in some cases rob surrounding forests of nitrogen. Reservoirs can also be significant sources of greenhouse gas emissions.Put simply, many dams have high environmental costs that outweigh their value. Removing them is the only sensible answer. And taking them down can often make economic sense as well. The River Alliance of Wisconsin estimates that removing dams in that state is three to five times less expensive than repairing them.
The message has been slowly spreading around the country. More and more communities and states have reclaimed rivers lost to jackhammers and concrete. Last year, 51 dams in 18 states were taken down, restoring more than 500 miles of streams, according to the group American Rivers. Nearly 850 have been removed in the last 20 years, and nearly 1,150 since 1912.
But the work is far from done. I was disappointed to see the Energy Department release a report last week on the potential to develop new “sustainable” hydroelectric dams on rivers and streams across the country. The report follows President Obama’s signing of two laws last year to encourage small hydro projects and revive nonproducing dams.
New dams are a bad idea. We’ve glorified them for decades, but our pride in building these engineering marvels has often blinded us to the environmental damage they cause. The consequences run the length of the river and beyond. Our many complex attempts to work around these obstacles would make Rube Goldberg proud. Interventions like fish elevators and trap-and-haul programs that truck fish around impoundments don’t lead to true recovery for wild fish populations or reverse the other environmental problems caused by blocking a river’s flow.
But we do know that removing dams brings streams and rivers back to life and replenishes our degraded aquifers.
by Yvon Chouinard, NY Times | Read more:
Image:Marta Monteiro
