1812 Quemahoning Dam on Rhoads Creek near Boswell, PA

(Satellite)

Jackson-Township historical preservation posted
The Quemahoning Dam in Somerset County in 1910. The Quemahoning is the largest dam in Pennsylvania.
[Since this postcard was published, larger dams have been built in PA. The comments disagree on what is currently the largest dam.]

Dam and outlet control structure.

benshoffhillwater
This is one of the dams built upstream from Johnstown, PA, to provide the steel mills with water.

Emergency spillway.

Blair Otto commented on the above post
Is not this it?

Jackson-Township historical preservation posted

Construction of the Spillway Guard Wall and Foundation Plan for the spillway length looking upstream at the Quemahoning Dam in Somerset County on July 2, 1912.

(Photo from https://www.facebook.com/ConemaughTownshipAreaHistoricalSociety/)

Jackson-Township historical preservation posted

Construction of the Quemahoning Dam in Somerset County on August 18, 1911.

(Photo from http://www.cambriasomersetwater.com/)

TheStonyCreek

"For generations, Quemahoning Lake was the private property of steel companies – first belonging to its developer, the Cambria Steel Company of Johnstown, then to Cambria’s successor, Bethlehem Steel Corporation. Built between 1907 and 1912, the dam was originally 90 feet high and 950 feet long at the top, 70 feet wide at its base, and contained almost 11 billion gallons of water. At the time of its development Quemahoning was the largest impoundment in Pennsylvania. The dam’s spillway was improved with a series of steps in the 1930s, and its height was increased by seven feet in 1961, enabling the dam to store up to 14 billion gallons.

"Simultaneous with the dam’s initial construction, a 14-mile pipeline was laid from the dam to the steel mills in Johnstown. This 66-inch-diameter line could deliver up to 80 million gallons of water daily to the mills, which used the water in steelmaking and in the production of steam that once powered much of the mill’s equipment."

This is one of five dams and reservoirs that were bought from Bethlehem Steel.

CambriaSomersetWater