Remove or Repair?
Dam Safety Concerns Provide Window of Opportunity for RestorationIn the aftermath of catastrophic flooding in New Orleans from Hurricane Katrina and extreme storm events in the Northeastern United States that brought several dams to the breaking point, renewed attention has been focused on the growing crisis of dam safety in the US. River-protection groups would like to turn this crisis into an opportunity for river restoration through the removal of obsolete and unsafe dams. These events brought attention to the need for stronger state and federal dam safety policies and programs, and the poor state of repair of many of the nation's dams and levees. State dam safety officials have identified more than 3,500 unsafe or deficient dams nationwide, and many dam owners lack the funds required to bring the structures into compliance with state regulations.
This year's extreme weather had impacts on dams and levees in a number of US states. In New Jersey, one low-hazard dam failed and a significant-hazard dam was overtopped but did not fail. Downstream residents were evacuated. Several coastal dams along the Jersey shore reached record levels, which resulted in extensive flooding in upstream communities. Similarly in New Hampshire, flooding from the storm overtopped and damaged several dams.
Then on March 14 a dam break in Kauai released nearly 500 million gallons of water, claiming seven lives and raising fears about the safety of dozens of similar privately owned dams across Hawaii. The century-old earthen dam collapsed after days of heavy rain swelled the Kaloko Reservoir behind it. The water swept away houses on two multimillion-dollar properties in the rugged hills of the island, cutting a three-mile path of destruction to the sea. Nearly all of Hawaii’s dams were built early in the past century before federal or state standards existed.
In October 2005, the American Society of Civil Engineers had identified at least 22 dams in the Hawaiian Islands with deficiencies that raised safety concerns. The society has been monitoring 130 dams in Hawaii. The dam on the Kaloko Reservoir was not on the list of dams rated “high-hazard” structures that could cause deaths and significant damage if they failed.
In mid-March, representatives from New York, Utah and Hawaii introduced legislation to reauthorize the National Dam Safety Program. The Dam Safety Act of 2006 would provide up to $12.7 million a year for four years to assist states in improving their dam safety programs. Hawaiian Senators also introduced the Dam Rehabilitation and Repair Act of 2006, which would provide up to $350 million over four years to repair and upgrade unsafe dams in the United States.
While the lawmakers and engineering groups are pressing for renewed attention to improving the condition of potentially dangerous dams throughout the US, conservationists and river managers are concerned that proposed legislation will force repair and rehabilitation of dams that should be removed.
Incorporating dam removal into effective dam safety programs is well-established in states like Wisconsin and Pennsylvania, and is gaining ground elsewhere, such as Ohio and Minnesota. However, states without migrating fish species tend to face greater obstacles to acceptance and funding for dam removal.
An examination of small dams removed through consensus process in Wisconsin showed that dam removal typically cost two to five times less than the estimated safety repair costs. By reducing costs at obsolete dams, funds under this bill could be stretched to address safety threats at even more dams.
Across the country, hundreds of thousands of aging, small dams that once served to provide power for grist mills, sawmills and iron ore operations still interrupt the flow of streams. Some continue to provide recreational and commercial uses, but many pose a safety threat, make the water overly warm for aquatic life, impede fish attempting to migrate upstream, and can be a nuisance for canoeists.
A large obstacle to their removal is cost, with some owners being quoted seven-figure price tags for demolition of small dams. This is where private/public efforts enter the picture. Groups such as Trout Unlimited and American Rivers are providing engineering expertise to significantly lower removal costs, while agencies such as the Pennsylvania Fish and Boat Commission offer similar help and sometimes have grant money available.
Though responsible dam decommissioning can have a large price tag, it can add up to long-term savings through the removal of insurance liability and maintenance and repair costs, enhanced ecological and property values, and even in reduced flood damage from the restoration of wetlands and floodplains.
Today, the nation has an excellent opportunity to evaluate aging, unsafe dams as candidates for decommissioning and river restoration. We must not let this window of opportunity for healthier rivers and ecosystems close.