Dam Info


Crystal Lake Dam is an earth-filled embankment dam. It is approximately 1200 feet long, 10-feet high containing an approximate 110' long concrete core, approximately centered on a 41' wide concrete trough spillway.

The spillway is approximately 31' feet long with 3' concrete sidewalls. The spillway descends approximately 3' onto a concrete drop apron, trapezoidal in shape, after which the discharge flow spills into an outflow channel approximately 100' from its confluence with the Ramapo River.

A 36-inch diameter outlet pipe and slide gate on the eastern side of the spillway provide low-level outlet control.

Approximately 900' north of the spillway is a 24-inch diameter secondary low-level outlet pipe with control gate. The reinforced concrete pipe penetrates the embankment and exits through a concrete headwall on the easterly bank of the Ramapo River. The 24-inch low-level outlet structure provides an alternate means to lower the lake for maintenance.

RML is obligated to comply with the Safe Dams Act.

  • Administered by Department of Environmental Protection, Dam Safety and Flood Control Bureau. 
  • Objective: Protect lives and property from consequences of a dam failure. 
  • Achieves goal by requiring maintenance and periodic inspection of in-service dams.
  • Classifies dam design criteria in four categories according to Hazard (Crystal Lake Dam is Class III, Low Hazard).
  • Requires Owner to prepare an Operation & Maintenance Manual, conduct periodic maintenance, and to provide inspection and maintenance reports.
  • Requires Owner to authorize/pay for a regular inspection of a Class III dam by a NJ Professional Engineer every four years
  • Requires Owner to obtain a permit to modify or repair an existing dam
  • Violations of Safe Dams Act and failure to follow orders are liable to a penalty of not more than $5,000 per day.
  • RML’s NJ professional engineer submitted the 2012 Regular Inspection Report for Crystal Lake Dam.  NJDEP Dam Safety accepted the report.