ASDSO released the new numbers Jan. 29, noting cost estimates for repairs and upgrades have increased significantly since a 2003 ASDSO report. The 2003 report placed the cost at $36 billion for all dams, including $10.1 billion for high-hazard-potential dams.
There are about 85,000 regulated dams in the U.S. As dams age and downstream development increases, the number of deficient dams has risen to more than 4,000, including 1,819 deficient high-hazard-potential dams.
Over the past six years, for every deficient high-hazard-potential dam repaired, nearly two more were declared deficient. In 2006, ASDSO told a congressional oversight hearing the number of state-regulated dams identified as unsafe is increasing at a faster rate than they are being repaired. (HNN 7/31/06)
Of the $16 billion that would be directed toward high-hazard dams �- those dams whose failure likely would cause loss of human life �- about $8.7 billion is needed to repair publicly owned dams. The remaining $7.3 billion is needed to repair privately owned dams, ASDSO said.
Furthermore, to eliminate the backlog of 1,819 deficient high hazard-potential dams over ten years, the number of high hazard-potential dams repaired will need to be increased by an additional 270 dams per year above current numbers, ASDSO said. That effort, it said, represents an annual cost of $850 million. ASDSO estimates that, in 2007, about $700 million was spent collectively to rehabilitate about 341 dams, citing state data completed that year.
Regulators classify a dam based on the downstream consequences should the dam fail or experience a serious incident. The classification has nothing to do with a dam's condition or safety, ASDSO explained. A high-hazard-potential classification does not mean the dam is deficient, the association added.
ASDSO released the new numbers at a time when the new Congress and the Obama administration are working on an economic stimulus package that would include billions of dollars for infrastructure improvements. (HNN 1/28/09)
The latest data from the National Inventory of Dams, maintained by the Corps of Engineers, indicates the number of deficient dams in the U.S. is increasing, up by 36 percent in the last five years, ASDSO said.
While federal agencies own only about 4 percent of the 85,000 dams in the U.S., those dams also face formidable challenges, ASDSO said. It cited several large federal dam rehabilitation projects now in progress, including 198.72-MW Folsom in California (HNN 5/12/08), 270-MW Wolf Creek in Kentucky (HNN 8/4/08), and 135-MW Center Hill in Tennessee (HNN 2/28/08).
ASDSO recommends a federal program be established to fund dam rehabilitation, encouraging state funding programs, providing for cost sharing, and stretching funds to maximize the number of dams that will be rehabilitated.
ASCE 2009 Infrastructure Report Card gives dams a 'D'
The American Society of Civil Engineers used ASDSO's new dam numbers in its 2009 Infrastructure Report Card, released Jan. 28. U.S. dams earned a �D� on ASCE's 2009 Report Card for America's Infrastructure, the same grade it earned in the previous report card, in 2005.
In the newest report, ASCE identified a five-year investment need of $2.2 trillion from all levels of government and the private sector for the nation's infrastructure. ASCE said there has been little change in the condition of roads, bridges, drinking water systems, and other public works since its 2005 assessment. During that period, the cost of improvements has increased by more than half a trillion dollars, it added.
The 2009 report card was developed by an advisory council of civil engineers representing the various infrastructure categories, as well as a broad spectrum of civil engineering disciplines. Each category was evaluated on the basis of capacity, condition, funding, future need, operation and maintenance, public safety, and resilience. A detailed report is scheduled for release in late March.