Since working for the City Water Department, I can only remember three times that we have used the Susquehanna River as a source of supply during a drought. I know it was used when it was first built in 1966. The first time I saw the water from the Susquehanna being dumped into our waste lake, I became fascinated with the river. A couple years ago I started documenting the Susquehanna through photographs (Another story, another time)
The history of the river and its role in supplying Baltimore with water starts in 1919 when an electrical engineer from Pennsylvania Power suggested to the consulting engineers, that they could build a tunnel, 32 miles in length from the Susquehanna to Loch Raven Reservoir, to a new dam there with hydro-electric capabilities. His plan was referred to as the Keilholtz Scheme. The consultants brushed him off.
Between 1926 and 1928 the Conowingo Dam was built. In the 1950s it was thought about once again to use the Susquehanna as a water supply, so in 1960 a tunnel was started. It was referred to as the “Big Inch” as it was 108 inches in diameter. Instead of going to Loch Raven, it was built to connect the Montebello Plant, in Baltimore, with the Susquehanna. A total of 38 miles. It was completed in 1966, just in time for the drought.
The photos above show the building of the coffer dam, in the Susquehanna, to hold back the water as they build the intake structure. and a photo of the interior of the tunnel.