United Water New York said this afternoon its dams in Rockland County, including the Lake DeForest dam in West Nyack, have passed a post-Hurricane Irene inspection.
Company officials said the dams are in good condition despite heavy rains and significant flows of water from Sunday’s storm, which brought flooding in neighborhoods throughout Rockland County.
“Irene was one of the most significant rain events in the history of Rockland and Orange counties,” said Michael Pointing, vice president and general manager of United Water New York. “As an example, our preliminary study indicates that approximately 1.7 billion gallons of water flowed into the Hackensack River during this storm. That is over 170 times the normal flow of 9.75 million gallons.”
United Water says inspections were done by its own engineers and the BS&J engineering consulting firm, with the findings reported to the state Department of Environmental Conservation.
The inspections looked at dams at:
- Lake Deforest
- Potake Lake
- Stony Point
- Indian Kill
Pointing said the dams were inspected three times in the past week.
“Dam safety is a high priority for United Water,” Pointing said. “To ensure the integrity of our water treatment facilities, we inspected the dams after last week’s earthquake, during the hurricane, and following the hurricane. The reports indicate that the dams withstood these significant natural events.”
On the Thursday night before the Hurricane Irene hit the area, United Water said it started releasing extra water from Lake DeForest as a precaution, with approval of the state DEC.
“By lowering the reservoir prior to the storm, we were able to avoid stability issues and did not have to issue a Dam Advisory,” Pointing said.
A Dam Advisory would have been issued at Lake Deforest if elevation levels in the reservoir had reached 87 feet.
Clarkstown and state DEC officials said they have received complaints from residents south of Lake DeForest that United Water should have been releasing water much earlier in anticipation of Hurricane Irene. Before the storm, the Lake DeForest reservoir was nearly at 100 percent capacity. Homes and streets south of the dam had heavy flooding in the storm.
United Water spokesman Steve Goudsmith said the company’s engineers were closely monitoring the dam in the week before the storm and the utility sought state permission to lower reservoir levels as soon the engineers decided that step should be taken.
State DEC Commission Joe Martens, who inspected the Lake DeForest dam and flooding throughout Clarkstown on Sunday, said his agency encouraged United Water throughout the week before the storm to reduce reservoir levels. Martens said that in the aftermath of the storm, New York needs to review issues such as controlling reservoir levels in advance of major storms.
Clarkstown town Supervisor Alex Gromack said he does not believe there is enough clarity in state regulations on who is responsible for overseeing facilities such as the Lake DeForest dam and who should make the call on whether water must be released as a safety measure.
Gromack said Martens' tour of the dam and flooding throughout the Town Of Clarkstown was critical for the town, which Gromack said is working with state environmental officials on future flood-control projects. Gromack credits flood-control efforts taken over the past year for alleviating cronic problems that were faced in neighborhoods such as Congers and Valley Cottage for many years.
The Lake DeForest dam lost power service from Orange and Rockland Utilities during the hurricane, but Goudsmith said an on-site generator was able to provide power to operate the facility.
In western Ramapo, the Potake Dam, which is used to augment water supplies in the Ramapo River, did reach a Dam Advisory elevation. The advisory triggers notifications to the local offices of emergency management and creates a heightened sense of awareness, according to United Water.
“Potake Dam has been thoroughly inspected and continues to operate safely,” Pointing said. “Now that water levels are receding, the Advisory should be lifted shortly.”
United Water reported that there were few interruptions of water service in Rockland during the storm. United Water supplies drinking water to over 280,000 people in Rockland and parts of Orange counties.
However, the Waldron Terrace area of Sloatsburg became a problem because the storm washed away a bridge needed to reach a water main break. United Water says it rigged a temporary water line to help that area and provided residents with bottled water.