Engineering Division


The Engineering Division is responsible for the operation and maintenance of Lake Orange, monitoring Eno River flows and initiating water use restrictions during low-flow periods as regulated by the Eno River Voluntary Water Management Plan. In addition, engineering staff collaborate on other County-constructed public infrastructure projects and economic development infrastructure design.

  1. Lake Orange Information
  2. Efland Sewer System

Lake Orange

  • Lake Orange is owned and operated by Orange County and is located on the east fork of the Eno River in Cedar Grove.  The lake was constructed by Orange County in 1968 (using Orange County funds) to help bolster the public drinking water supply for the Hillsborough area.  
  • Lake Orange is a Class II (WSII) public water supply reservoir with additional classifications by NCDEQ as High Quality Waters (HQW) and Nutrient Sensitive Waters (NSW).  
  • Lake Orange has a total water surface area of approximately 160 acres at normal pool (Elevation = 615-ft) and a total volume of approximately 474 million gallons at normal pool.  
  • The Lake Orange dam is an earthen berm approximately 1,100 feet long and approximately 40 feet high at its tallest point.  Integrated into the dam is a 100-ft wide emergency spillway weir and a trapezoidal concrete spillway channel.  Water releases from Lake Orange are monitored and controlled via an automated gate and manual gates located within a concrete intake tower near the center of the dam.
  • The Lake Orange dam was classified by NCDEQ as a “High Hazard” dam in August 2011 which means that failure of the dam could result in severe property damage and/or possible loss of life downstream.
  • Orange County actively monitors and inspects the Lake Orange dam and maintains an Emergency Action Plan (EAP) in conformance with North Carolina Dam Safety standards.
  • The land upon which the lake is located was donated to Orange County by five (5) local landowners in the late-1960s, in exchange for exclusive recreational rights (e.g. fishing, boating, etc.) to the lake’s surface.  Those recreational rights are designated to Lake Orange, Inc., a private corporation formed and owned by the legacy donating landowners.  
  • Orange County owns the land upon which Lake Orange is located (i.e. from elevation 615-ft downwards), as well as the land upon which the dam and spillway/outlet structures are located. Orange County also holds a 5-foot vertical flood-stage easement along the perimeter of the lake (i.e. from elevation 615-ft to elevation 620-ft).  
  • Orange County is obligated to release minimum flows from Lake Orange throughout the year, as defined within the Eno River Voluntary Water Management Plan.
  • Eno River Voluntary Water Management Plan - Background information and rules used to determine when to release water and how much to release from Lake Orange.
  • Eno River USGS Gauge (#02085000) - This shows the flow in the Eno River at the USGS gauge in Hillsborough. This is the USGS gauge used in the Eno River Voluntary Water Management Plan to monitor flow in the Eno River.