A new Department of Environmental Protection Police headquarters was unveiled in Valhalla Wednesday, replacing an old facility in Yorktown.

The building was dedicated to members of the DEP police who have been protecting the New York City watershed for the past 100 years. The New York City DEP owns 19 reservoirs in eight counties, including Westchester and Putnam.

The DEP police was formed in 1907 to patrol a 2,000-square mile watershed area. The new state-of-the-art facility will be headquarters for the part of the force east of the Hudson.

Meanwhile, another dedication ceremony also took place Wednesday. The DEP dedicated a flag plaza to a unit of the New York National Guard that helped protect the watershed during World War I. Forty soldiers died during that effort.