1952 Mt. Morris Dam on Genesee River in Letchworth State Park

(Satellite, 426 photos)

I thought this dam would be close to the former-Erie Portage Bridge, but it is not that close because I now see that the Letchworth State Park is long.

I was surprised when I looked at the satellite image and saw more water on the downstream side than on the upstream side. This dam does just flood control.

USACE, Buffalo District, Photo by: Mount Morris Dam Volunteer Bob Oswald

Marilyn Coté Miller posted
Yesterday, (7/3/23) did a tour inside the Mt Morris Dam on the Genesee River at Letchworth St Park. The tour costs $1. You go down 150’ into the tunnels inside the dam. Very interesting.

The reservoir can hold 301,853 acre-feet. "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. As soon as downstream conditions permit, the stored water is released gradually through the nine conduits at the base of the spillway sections. About 30 days are required to empty a full reservoir at a rate that would safely avoid damage to downstream properties....During Tropical Storm Agnes in 1972, $210 million in damages alone were prevented, primarily in the Rochester Metropolitan Area. At that time, 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. An inflow of the magnitude of Tropical Storm Agnes is expected to occur on an average of every 300 years." [USACE_history] I wonder how close the impounded water gets to the railroad bridge that is upstream from here.

It must not impound water very often because I could not find any photos with water stored behind the dam.

USACE, Buffalo District, Photo by Avery Schneider

John Kucko Digital posted three photos with the comment: "Mount Morris Dam:  The ultimate flood protection along the Genesee River is this right here—the Mount Morris Dam.  Opened in 1952, it’s estimated the dam has saved over $1 billion in potential flood damage throughout the Genesee Valley through the years.  Made a quick stop there today, lots of ice chunks and tree debris as expected.  Also, the last shot is of one of Letchworth State Park’s tallest cascades that often runs dry."

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Lorrie Harris commented on John's post
This picture was taken in 1972. At least that what I wrote on the back. We had a hurricane tear through New York and this was the result.
Thomas Sandford: Lorrie Harris hurricane Agnes

 

Jeff Church commented on John's post
Was Dry in august, Has the water ever gone over the top of it??? If so that would be crazy.
Karen Gibson: In 1972 water was only feet from the top of the dam. Openings at the bottom (9) were opened all the way to stop overflowing. Damage to the dam basin on the north side would have been great from the debris over the top. Flow was regulated until danger was past. Flooding downstream was kept to a minimum. The damn was completed only 20 yrs. earlier and paid for itself in 1972.
Andy Fraser: Karen Gibson I remember going to see the Dam then and all the talk was if it was would hold. It had never been tested like that before. I believe it was two feet from over flowing.

Connie Ash Tartick commented on John's post
John I found this photo among my parents photos. Thought you might enjoy this photo of the progress of the building of the dam.

2:52 video about the removal of debris