The massive Mount Morris Dam, situated deep in the Genesee River gorge near the northern end of Letchworth State Park in Livingston County, NY, has been a shield from the destructive power of Mother Nature since its completion in 1952. The U.S. Army Corps of Engineers Buffalo District contributes to its success through operation and maintenance of three missions areas: flood risk management, environmental stewardship, and recreation.
“The Mount Morris Dam has successfully mitigated the risk of catastrophic flooding along the lower Genesee Valley for decades,” said Steve Winslow, manager of the dam. “It’s prevented an estimated $2.2 billion in flood damage throughout its life, protects over 160,000 people in the Genesee River 100-year flood plain, and provides recreation opportunities to thousands of visitors each year.”
The dam was authorized by Congress in the Flood Control Act of 1944, and constructed from 1948 to 1952 at a cost of $25 million. Completion of the dam significantly reduced the risk of flood disaster which had threatened the Genesee River valley for hundreds of years. When river flows exceed the natural capacity of the downstream channel and flood damage is likely to occur, flood waters are stored in the dam’s reservoir.
“The reservoir in the river gorge holds water and significantly reduces risk damages during catastrophic flooding events in downstream areas, including the City of Rochester,” said Adam Hamm, Buffalo District Chief of the NY-PA Operations and Maintenance Section. “The reservoir’s capacity is over 300,000 acre-feet - equivalent to over 140,000 Olympic sized swimming pools - enough to protect the basin below from all but very infrequent floods.”
While the dam prevents a degree of flooding nearly every year, there have been extreme cases when the dam was a godsend for downstream residents. For example, during Tropical Storm Agnes in 1972, the dam prevented $210 million in damages, primarily in the Rochester Metropolitan Area. At the time, inflows exceeded the storage capacity of the reservoir and Mount Morris Dam staff released water through the gates of the dam to prevent overtopping of the spillway. Overtopping would have caused debris to accumulate in the reservoir and pass downstream, creating log jams and additional damages.
“We’re proud to help save lives and taxpayer dollars by operating the dam effectively,” said Winslow. “Our District’s water management team works with National Weather Service forecasting partners to develop a strategy for each hydrologic event, and then prescribes desired outflows to staff at the dam. Dam operators adjust gate settings to allow for the desired flow. When natural flow-rates are restricted, a deep lake of stored water builds behind the dam. Once the weather system has passed and river flows are naturally reduced, we re-open gates gradually to carefully release the stored water and regain storage capacity for the next event.”
A distinctive feature of the Mount Morris Dam is that it’s not permitted to maintain a constant reservoir level. During dry seasons, gate settings are adjusted to allow the natural river flow to occur, meaning that the Letchworth Gorge remains ecologically intact for the benefit of all who appreciate Letchworth State Park.
A public recreation area is also associated with the dam and offers a variety of recreational opportunities free of charge. Visitors can hike trails on foot or bring a bicycle, snowshoes, or skis, and they can observe local animals including bluebirds, bald eagles, and white-tailed deer. A variety of picnic areas and two playground areas are also available. The most popular recreation attractions at the Mount Morris Dam are the William B. Hoyt II Visitor Center and ranger-guided tours inside the dam.
“Natural resources at the Mount Morris Dam and Recreation Area are managed to promote a safe and aesthetically pleasing environment for the visiting public and to enhance biodiversity of flora and fauna,” said Hamm.
Routine maintenance is required for the Corps of Engineers to successfully execute each of its mission areas at Mount Morris.
“We employ a diverse staff – park rangers, maintenance mechanics, electricians, natural resource specialists, just to name a few,” Winslow said. “Our workforce maintains the dam and surrounding property by updating hydraulic systems, renewing backup power generators, checking instruments and indicators, repairing recreation areas, caring for wildlife habitat, removing debris, and much, much more.”
“As the Nation ages, so does its infrastructure,” said Winslow. “I am proud to say that the U.S. Army Corps of Engineers has routine processes in place to ensure that structures like Mount Morris Dam continue to function as they were designed, and continue to minimize risk of disastrous flooding.”
For more information please visit: https://www.lrb.usace.army.mil/Missions/Recreation/Mount-Morris-Dam/
Or contact the Mount Morris Dam at:
U.S. Army Corps of Engineers
Mount Morris Dam and Recreation Area
6103 Visitor Center Road
Mount Morris, N.Y. 14510
Phone: (585) 658-4790