Conowingo Dam

Conowingo Dam
Conowingo Dam, aerial view (1936)
Conowingo Dam is located in Maryland
Conowingo Dam
Location of Conowingo Dam in Maryland
Official nameConowingo Hydroelectric Station
CountryUnited States
LocationCecil and Harford counties, Maryland
Coordinates39°39′36″N 76°10′26″W / 39.66000°N 76.17389°W / 39.66000; -76.17389
StatusOperational
Construction began1926 (completed in 1928)
Opening date1928
Owner(s)Susquehanna Electric Company
Dam and spillways
Type of damGravity dam
ImpoundsSusquehanna River
Height94 ft (29 m)
Length4,648 ft (1,417 m)
Reservoir
CreatesConowingo Reservoir
Total capacity310,000 acre⋅ft (0.38 km3)
Active capacity71,000 acre⋅ft (0.088 km3)
Surface area9,000 acres (3,600 ha)
Maximum length14 mi (23 km)
Maximum water depth105 ft (32 m)
Normal elevation109.2 ft (33.3 m)
Power Station
Operator(s)Constellation Energy
Commission date1928
TypeRun-of-the-river
Turbines7 x 36 MWe, 4 x 65 MWe
Installed capacity548 MWe
Website
Conowingo Hydroelectric Generating Station

The Conowingo Dam (also Conowingo Hydroelectric Plant, Conowingo Hydroelectric Station) is a large hydroelectric dam in the lower Susquehanna River near the town of Conowingo, Maryland. The medium-height, masonry gravity dam is one of the largest non-federal hydroelectric dams in the U.S., and the largest dam in the state of Maryland.

The dam sits about 9.9 miles (16 km) from the river mouth at the Chesapeake Bay, 5 miles (8 km) south of the Pennsylvania border and 45 miles (72 km) northeast of Baltimore, on the border between Cecil and Harford counties.

The dam supports a 9,000-acre reservoir, which today covers the original town of Conowingo. During dam construction, the town was moved to its present location about 1 mile (1.6 km) northeast of the dam's eastern end. The rising water also would have covered Conowingo Bridge, the original U.S. Route 1 crossing, so it was demolished in 1927. U.S. Route 1 now crosses over the top of the dam.

The Conowingo Reservoir, and the nearby Susquehanna State Park, provide many recreational opportunities.