New York State

The "East of Hudson" reservoirs are a series of natural water bodies, mainly in Putnam and Westchester Counties east of the Hudson River north of New York City, that provide much of the city's drinking water. One of the ongoing threats to these reservoirs is eutrophication, or choking of the water body from the decay of excessive plant material. This excess plant material is mainly due to phosphorus inputs in the form of septic and lawn fertilizer runoff from surrounding residential development in the city's growing northern suburbs.