The Mount Morris Dam is a concrete

dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use ...

on the

Genesee River The Genesee River is a tributary of Lake Ontario flowing northward through the Twin Tiers of Pennsylvania and New York in the United States. The river provided the original power for the Rochester area's 19th century mills and still provides h ...

. It is located south of

Rochester, New York Rochester () is a city in the U.S. state of New York, the seat of Monroe County, and the fourth-most populous in the state after New York City, Buffalo, and Yonkers, with a population of 211,328 at the 2020 United States census. Located in W ...

in the towns of Leicester and Mount Morris in Livingston County, New York, next to

Letchworth State Park Letchworth State Park is a New York State Park located in Livingston County and Wyoming County in the western part of the State of New York. The park is roughly long, following the course of the Genesee River as it flows north through a dee ...

History

The Mt. Morris Dam was built between 1948 and 1952 by the Buffalo District office of the

U.S. Army Corps of Engineers , colors = , anniversaries = 16 June (Organization Day) , battles = , battles_label = Wars , website = , commander1 = ...

(USACE). The project was authorized by the

United States Congress The United States Congress is the legislature of the federal government of the United States. It is bicameral, composed of a lower body, the House of Representatives, and an upper body, the Senate. It meets in the U.S. Capitol in Washing ...

in the

Flood Control Act of 1944 The Pick-Sloan Flood Control Act of 1944 (P.L. 78–534), enacted in the 2nd session of the 78th Congress, is U.S. legislation that authorized the construction of numerous dams and modifications to previously existing dams, as well as levees acros ...

at a cost of $25 million. Prior to the construction of the dam, the Genesee River Valley and the city of

Rochester Rochester may refer to: Places Australia * Rochester, Victoria Canada * Rochester, Alberta United Kingdom *Rochester, Kent ** City of Rochester-upon-Medway (1982–1998), district council area ** History of Rochester, Kent ** HM Prison ...

had experienced periodic flooding. The flood of 1865, which developed flows exceeding per minute, resulted in massive destructions with flows equating half the flows of

Niagara Falls Niagara Falls () is a group of three waterfalls at the southern end of Niagara Gorge, spanning the border between the province of Ontario in Canada and the state of New York in the United States. The largest of the three is Horseshoe Fall ...

. Severe floods occurred every seven years on average between 1865 and 1950. Prior projects in Rochester, including retaining walls and a deepening of the river, were insufficient to stop a major flood event. The USACE states that, in the years since the completion of the dam, an estimated $1 billion in flooding damages have been prevented. In June of 1972,

Hurricane Agnes Hurricane Agnes in 1972 was the costliest hurricane to hit the United States at the time, causing an estimated $2.1 billion in damage. The hurricane's death toll was 128. The effects of Agnes were widespread, from the Caribbean to Canada, ...

passed over the Genesee Valley, causing over 7 inches of rain to fall across the entire valley in a short period of time. The water inflow due to Hurricane Agnes 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 damage. Inflows of this magnitude are only expected to happen an average of every 300 years. An estimated $210 million in damages was prevented by the dam during the storm.

Commemorations

June 2002 commemorated the 50th anniversary of the completion of Mount Morris Dam. A celebration and dedication of the commemorative kiosk was held to honor and recognize the men and women employed by the U.S. Army Corps of Engineers, Buffalo District and Mount Morris Dam Builders, 1948-1952. The kiosk rests on a foundation of bricks, each of which is inscribed with the name and occupation of the builders.

Visiting Centers

The William B. Hoyt II Visitor Center at Mount Morris Dam, opened by the U.S. Army Corps of Engineers in 1999, was built to accommodate the thousands of people who visit the dam each year. This center features a large atrium, museum, theater and public restroom facilities.

Project facts

General
Distance from mouth of Genesee River: .
Drainage area above dam: .
Drainage area below dam: . Dam
Type: Concrete Gravity/Dry.
Total length: .
Top width: .
Maximum height above river bed: .
Top elevation: above sea level. Spillway
Total length: .
Crest elevation: . Reservoir
Length in River Miles: at Maximum flood control pool.
Water Surface Elevation: above sea level at Maximum flood control pool.
Storage Volume: at Maximum flood control pool. Outlet Works
Type: Rectangular conduits.
Location: Base of spillway.

References

External links