Rondout Reservoir

Rondout Reservoir
Name	Rondout Reservoir
Location	Towns of Wawarsing and Rochester, Ulster County, New York, United States
Coordinates	41.7975°N 74.4397°W
Type	reservoir
Inflow	Rondout Creek, tributaries including Merrill Creek, Bennett Brook
Outflow	Delaware Aqueduct (via tunnel to Ashokan Reservoir, Catskill Aqueduct)
Catchment	176 sq mi
Area	1,900 acres
Max-depth	180 ft
Volume	49.6 billion US gallons
Elevation	420 ft
Constructed	1937–1954
Operator	New York City Department of Environmental Protection

Rondout Reservoir is a large man-made impoundment in the upper Delaware River watershed that serves as a principal storage component of the New York City water supply system. Located in Ulster County, New York near the Catskill Mountains and the Shawangunk Ridge, the reservoir collects water from the Rondout Creek basin and transfers it via the Delaware Aqueduct into the West Branch Reservoir and ultimately to New York City through the Catskill Aqueduct and the Delaware System. It functions alongside the Ashokan Reservoir, Neversink Reservoir, and other upstate reservoirs to meet municipal demand and interface with regional water infrastructure projects like the Delaware Aqueduct repair and the Catskill-Delaware Water Supply program.

History

The site was within lands long occupied by the Lenape and later settled in the colonial era by inhabitants of New Paltz and Kingston (New York). During the 19th century industrialization of the Hudson River valley and expansion of the Erie Canal corridor, increasing urbanization in New York City prompted early water-supply planning such as the Croton Aqueduct, the Ashokan Reservoir project, and later the Catskill Watershed. In the 1930s and 1940s, as Mayor Fiorello H. La Guardia and agencies like the New York City Department of Water Supply, Gas and Electricity expanded municipal services, the decision was made to construct a major storage reservoir on the Rondout drainage to connect the Delaware River basin to the city's waterworks. Construction began under New Deal–era infrastructure activity overlapping with projects like the Tennessee Valley Authority and wartime public works; completion and commissioning occurred in the early 1950s during the administration of Mayor Vincent R. Impellitteri and later managed by the New York City Department of Environmental Protection.

Geography and Hydrology

The reservoir occupies a valley near the Shawangunk Ridge and drains a basin bounded by portions of Sullivan County, New York and Ulster County. Major tributaries feeding the impoundment include the Rondout Creek mainstem, Merrill Creek, and Bennett Brook, with headwaters originating in upland forests near Otter Kill and Stony Kill watersheds. Hydrologically it is part of the larger Delaware River Basin Commission planning region and contributes to interbasin transfer into the New York City water supply system. Seasonal snowmelt from the Catskill Mountains, precipitation patterns influenced by the Appalachian Mountains corridor, and storm events associated with extratropical cyclones and remnants of Hurricane Irene determine inflow variability. The reservoir's storage curve and stage-discharge relationships are used for regional flood control, aqueduct balancing, and coordination with the Delaware River Basin Compact and state agencies in New York (state).

Construction and Engineering

The project required acquisition of land, relocation of communities, and the erection of dams, spillways, and outlet works. Engineering works included construction of an earth-and-rockfill embankment, concrete spillway structures similar in principle to those at Ashokan Reservoir and Neversink Reservoir, and tunnels connecting to the Delaware Aqueduct, the longest continuous tunnel in the world, which links to the West Branch Reservoir and the Kensico Reservoir. Contractors employed techniques contemporary to mid-20th-century civil works, including rolled-earth compaction, impervious cores, and instrumentation for seepage monitoring analogous to instrumentation at the Hoover Dam and other major works. The reservoir's intake tower, draw-off gates, and pressure tunnel sections were integrated into the New York City water supply network and subjected to later retrofits during the Delaware Aqueduct repair project and routine maintenance overseen by the U.S. Army Corps of Engineers and state agencies.

Ecology and Water Quality

Surrounding lands include mixed hardwood forests, wetlands, and riparian corridors supporting species such as white-tailed deer, beaver, black bear, and migratory birds utilizing the Atlantic Flyway. Aquatic fauna include coldwater and warmwater fishes with management for species like smallmouth bass, walleye, and stocked rainbow trout in connected tributaries, while native populations of American eel and brook trout occur upstream of barriers. Water quality is managed to protect potable standards used by New York City; threats historically included sedimentation, nutrient loading from septic systems, invasive plants such as Phragmites australis and aquatic invasives like Hydrilla verticillata, and pathogens monitored under protocols similar to those applied in Catskill reservoirs. Programs by the New York State Department of Environmental Conservation and the New York City Department of Environmental Protection include watershed protection, sanitary surveys, and road-salt management coordinated with the Environmental Protection Agency guidelines.

Water Supply and Management

As a primary storage reservoir for the Delaware Division of the New York City water supply system, the impoundment supports transfers via the Delaware Aqueduct into the Catskill-Delaware supply that supplements the Croton system. Operational rules set by the NYCDEP involve balancing storage, releases, and delivery contracts governed by interstate compacts including the Delaware River Basin Commission agreements and state memoranda with New Jersey and Pennsylvania where applicable. During periods of drought, managed releases and emergency diversions are coordinated with facilities like the Kensico Reservoir and water-conservation measures in New York City and suburbs. Capital programs have included leak detection, intake modernization, and collaboration with federal programs such as the Safe Drinking Water Act compliance efforts administered by the EPA.

Recreation and Access

Public access around the reservoir is restricted to protect water quality; limited recreational activities are regulated by the NYCDEP and the New York State Department of Environmental Conservation. Nearby public lands in the Minnewaska State Park Preserve, Sam's Point Preserve, and sections of the Shawangunk Ridge offer hiking, birding, and climbing opportunities associated with regional attractions such as the Mohonk Preserve and the Walkway over the Hudson. Boating, fishing, and swimming on the reservoir itself are generally prohibited or controlled; angling is permitted in certain tributaries and downstream reaches under state licensure from the New York State Department of Environmental Conservation with season and catch limits.

Cultural and Environmental Impact

Creation of the reservoir required relocation of communities, cemeteries, and alteration of historic landscapes associated with settlers of New Paltz, Kerhonkson, and other local towns, prompting legal actions and compensation under eminent domain statutes in New York (state). The project shifted land-use patterns, affected indigenous sites linked to the Lenape, and generated cultural narratives preserved in local museums such as the Hurley Heritage Society and historical societies in Ulster County. Environmental consequences included habitat fragmentation, changes in aquatic connectivity impacting diadromous species historically using the Delaware River system, and long-term watershed protection initiatives inspired by conservation movements associated with figures like John Muir and organizations such as the Sierra Club. Contemporary discourse involves balancing municipal needs of New York City with regional conservation, ecosystem restoration projects, and climate-change adaptation measures promoted by state and federal agencies.

Category:Reservoirs in New York (state)