The Hollowbrook is a 15 mile stream that flows through Kent, Putnam Valley and Cortlandt, to its final destination in the City of Peekskill.   The stream provides vital habitat for a variety of flora and fauna and its watershed covers over 48 square miles of land and 20 tributary streams! This includes most of Putnam Valley and portions of Kent in Putnam County, and northern sections of Cortlandt and Yorktown in Westchester County.

The City of Peekskill owns the Wiccopee Reservoir at the northern end of the watershed, which has pure clean drinking water.  The Hollowbrook serves to carry water from the reservoir and tributaries to a pump station in Cortlandt near Pump House Road and Oregon Road.  Water is pumped up the hill to the city's water plant off Frost Lane, where it is tested, filtered and treated before being distributed to about 21,000 residents of Peekskill, Cortlandt and Buchanan.

The Northern Westchester Joint Water Works, pipes water from the Hollowbrook system to 23,000 additional residents in Cortlandt and Yorktown to supplement water from NYC's reservoir system to ensure a year-round supply of water.  Additionally, hundreds of homes and businesses in Putnam Valley, along the Hollowbrook and tributary streams, use private wells to supply their drinking water.