The Northern and Southern Long Island Watersheds

The Northern and Southern Long Island Watersheds are located on the extreme southeastern part of New York State and occupy an area of approximately 782,080 acres. The combined watersheds cover two counties: Suffolk, to the east, and Nassau to the west. The latter borders New York City. The agricultural area is found predominately within the eastern one-third of the watershed in Suffolk County.

Bounded on the north by Long Island Sound, between the forks by Peconic Bay, and on the south by the Atlantic Ocean, the watersheds have a high water-to-land ratio that provides moderate temperatures, mild winters, 42 inches of rainfall annually and an extended growing season.

The watersheds are characterized by excessively well to well drained soils composed mainly of glacial moraine and outwash deposits. With these soil conditions, abundant sunshine (more than any other area in New York), plentiful ground water and nearness to wholesale and retail markets, this area of Long Island is one of the most important agricultural regions in the state.

There are 669 farms and 27,111 acres of farmland within the watershed. Important agricultural industries include vegetable production, nursery stock, turf grass, floriculture and small fruit production.

Long Island has always been recognized for producing high quality ducklings. The duck industry has gone through a gradual decline over the years. However, the industry is still strong and produces over 2.5 million ducks per year.

One of the fastest growing industries is the wine and grape industry. There are more than 2,500 acres of vines and 32 wineries operating within this watershed. Furthermore, with more than 100 different crops grown, Long Island offers an agricultural diversity that few other areas in the state can equal.

All resource concerns in these watersheds revolve around sub-surface water quality. The 2.75 million Long Island residents depend upon a sole source aquifer for all of their uses. Although there is an ample supply of water, the quality of that water has been degraded by over fertilization practices causing high nitrate levels and pesticides being detected in ground water. Therefore, nutrient and pest management are of utmost importance with the growers in these watersheds.

Map of Northern and Southern Long Island Watersheds

For general and application information, visit our CSP homepage.

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Contact Information

District Conservationist

Allan Connell
USDA Natural Resources Conservation Service
423 Griffing Avenue
Riverhead, New York 11901
Telephone: 631-727-2315

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