The Croton Watershed & Southeast

Natural resources help to define Southeast’s community character. Residents of Southeast can identify with the rolling topography, the streams and reservoirs, and the broad vistas available from many local roads. The quality of this landscape is important to the residents of Southeast. The quality of the landscape is also important to the consumers of New York City’s drinking water as well as the consumers of local groundwater.


Southeast’s surface water, although a part of its natural beauty, is largely a product of human effort. In the late 1800s, New York City’s Croton Watershed System was created through the damming of the East Branch and Middle Branch of the Croton River.

Watershed Reservoirs & Waterbodies

Southeast has five of the watershed reservoirs in its borders: part of the Croton Falls, and all of the Middle Branch, Bog Brook, East Branch and Diverting Reservoirs. In addition, the Town is laced with streams, creeks, small ponds and the large natural waterbodies of Peach Lake, Haines Pond, Brewster Pond, and Lake Tonetta. Protection of surface water is important to Town residents because clean surface water enhances property values and aesthetic values, provides recreation opportunities, and protects the drinking water supply.

Water Quality & Protection

New York City Department of Environmental Protection monitors the quality of water within its reservoirs and institutes regulations and policies to protect the integrity of this drinking water resource. In 1990, a far-reaching surface water protection program began when New York City moved to protect its watershed. The Watershed Rules and Regulations were developed to protect the water quality from any additional degradation resulting from wastewater discharges into surface and groundwater, land use practices that result in non-point source runoff, and improper use of storage of materials such as pesticides, de-icing salt and solid waste.


The stress of development on lakes has led to increased phosphorus levels and accelerated eutrophication of Lake Tonetta, Peach Lake, and the New York City reservoirs. Eutrophication is a process by which a buildup of organic material, sediments, and nutrients results in chemical and physical changes within a waterbody.

Cause of Eutrophication

Eutrophication of waterbodies is generally driven by the quantity of phosphorus entering the water. Too much phosphorus creates algae, weeds, slimes and other organic by-products that degrade water quality. New York City considers any “non-source water” reservoir containing 20 milligrams per liter or more of phosphorus to be “Phosphorus-limited.” Of the five reservoirs located within Southeast, all are currently designated as phosphorus-limited at this time. In addition, the Muscoot Reservoir, the watershed for which extends into Southeast, is phosphorus-limited.