By Anthony DePalma

New York State’s oversight of thousands of dams has been so deficient in recent years that serious problems in dozens of dams holding back billions of gallons of water have gone years without being fixed, according to a report released on Tuesday by the New York State comptroller, Thomas P. DiNapoli.

The deficiencies of one dam in the report, on Rainbow Lake in the Adirondacks, were first noted 36 years ago but have not yet been corrected, the report said.

The report examined 32 dams, which all had structural, maintenance or other problems lasting years, though they were considered safe. Included in that list were two owned by the New York City Department of Environmental Protection, which runs the city’s drinking water system. Those dams are the Croton Falls Dam in Putnam County, and the Gilboa Dam in Schoharie County.

Both were found to have seepage and maintenance problems as well as other issues that have gone unresolved for 30 years. The 81-year-old Gilboa Dam also has structural problems, and is undergoing extensive repairs.

The State Department of Environmental Conservation, which is responsible for ensuring the safety of the more than 5,000 dams in New York, took enforcement action on only 3 of the 32 dams during the years covered by the comptroller’s report, 2004 through 2006.

The report also found that in some instances, dams went as much as seven years between inspections, even though the department’s own policies call for the biggest dams to be inspected every two years.

“We cannot allow dams to have serious problems that go unaddressed for years,” Mr. DiNapoli said in a statement. “The longer owners take to correct problems, the greater the deterioration and the cost of these repairs and the increased likelihood that this neglect could lead to failure.”

James M. Tierney, the state’s assistant commissioner for water resources in the Environmental Conservation Department, said the department had been aware of shortcomings in its dam safety program well before the comptroller’s report was completed and had been working to improve its inspection and enforcement.

“Dam safety was a kind of a poster child for what can happen if government neglects something important,” Mr. Tierney said in a telephone interview. “Unless a dam was about to fall down, the D.E.C. didn’t do anything about it,” he continued, in a reference to the administration of Gov. George E. Pataki.

The department reviewed a draft of the comptroller’s report late last year, and in February it proposed new rules that require owners of about 1,000 dams categorized as high hazard (located in areas where failure may cause loss of life or serious property damage) and medium hazard (in locations that could result in property damage but not loss of life) to hire qualified professionals to do regular inspections.

Owners will then have to file reports with the state, which will review them and do spot checks. The new regulations will also require more regular maintenance and better record-keeping.

The first of three public hearings on the proposed regulations is scheduled to be held on April 15 in Poughkeepsie.

Mr. Tierney said that many of the shortcomings in the dam safety program were related to staff shortages. From 2004 through 2006, the dam safety office had fewer than seven employees on average, and at one point was down to three inspectors for the entire state. Under the Spitzer administration, the dam safety staff increased to 20.

In the last year, the state has cracked down on the owners of 15 dams, who now are under administrative orders to make repairs, Mr. Tierney said.

Officials concede that self-monitoring will not necessarily eliminate safety problems. In 2006, a New York City dam inspector was found to have submitted photocopied weekly inspection reports without conducting inspections. Mr. Tierney said that the additional staff would reduce the chances for fraud in the state’s new self-inspection program because violations are considered criminal offenses.

Michael Saucier, a spokesman for the New York City Department of Environmental Protection, said that the city had not had a chance to review the comptroller’s report but that all of its 19 reservoir dams were regularly inspected and were safe. He said the city was spending $1 billion to renovate all the dams.

Some of the dams audited by the comptroller’s office are owned by municipal or county governments. At least one belongs to an energy company, and several are owned by developers or homeowners’ associations. The dam on Rainbow Lake, officials said, has been deteriorating for a long time.

Mr. Tierney said the Rainbow Lake dam was never given priority attention because it holds back water only during wet periods. At other times it is dry. The dam’s owner is listed as the Jason Roberts Development Corporation, but inspectors have had trouble contacting it.