On July 9, 1908, the first permanent police officers were appointed and assigned to the precincts in Peekskill, Garrison, Browns Station, and High Falls.

Captain McKay selected a number of qualified individuals from the civil service list with the intention of making them Aqueduct Police Sergeants.

At this time, the newly formed Aqueduct Police, a force of 350 officers (300 of these being mounted units) were tasked with ensuring order in the unruly construction site work camps.

The first Board of Water Supply Police Precinct was built in Spout Brook, approximately two miles from Peekskill, New York.

As of the present day, the DEP Police today still has the same mission guarding the water supply, and is a participant of the annual First Provisional Regiment memorial services, held at the Village of Sleepy Hollow, NY.

This Aqueduct Defense Memorial Service honors and remembers 40 soldiers who died while serving New York State during World War I. DEP Police provides an honor guard, cooperates with the NY state defense force, and local government officials to remember those perished while on aqueduct duties.