Mount Morris Dam
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The Mount Morris Dam is a concrete dam on the Genesee River. It is located south of Rochester, New York in the town of Mount Morris, New York, next to Letchworth State Park.
The dam was built between 1948 and 1952 by the Buffalo District office of the U.S. Army Corps of Engineers. The project was authorized by the United States Congress in the Flood Control Act of 1944 at a cost of $25 million.
Records show that the Genesee River Valley and the City of Rochester had experienced flooding since 1800, with severe floods occurring every seven years between 1865 and 1950. In the years since the completion of the dam, it is estimated that more than $1 billion in flooding damages have been prevented.
During Hurricane Agnes in 1972, $210 million in damages was prevented, primarily to the city of Rochester. During this event the inflows exceeded the storage capacity of the reservoir and it was necessary to release water through the gates of the dam, causing minor downstream flooding. These releases were made to prevent overtopping of the spillway. Had the spillway overtopped, accumulated debris in the reservoir would have passed downstream, causing log jams and additional damages. Inflows of this magnitude are only expected to happen an average of every 300 years.[1]
[edit] Project Facts
General Miles above mouth of Genesee River: 67
Drainage area above dam: 1075 sq. mi.
Drainage area below dam: 1391 sq. mi.
Dam
Type Concrete Gravity/Dry
Total length: 1028 ft
Top width: 20 ft
Maximum height above riverbed: 230 ft
Top elevation: 790 ft above sea level
Spillway
Total length: 550 ft
Crest elevation: 760 ft
Reservoir
Length in River Miles: 17 miles at Max. flood control pool
Water Surface Elevation: 760 ft above sea level at Max. flood control pool
Storage Volume: 301,853 Acre Feet (1 acre of water 1 ft deep) at Max. flood control pool
Outlet Works
Type: Rectangular conduits
Location: Base of spillway
Real-time Genesee River data may be obtained at: http://www.erh.noaa.gov/er/nerfc
