Lake Orange

Lake Orange is a 150-acre surface water reservoir located on the east fork of the Eno River in Cedar Grove, approximately 6 miles north of downtown Hillsborough. The lake is owned and operated by Orange County.

Lake Orange County View v2
Lake Orange Zoomed In
  1. General Information
  2. Inundation Zone Information
  3. Construction Project
Location/Address1005 Lake Orange Road, Hillsborough, NC 27278
Latitude36.146 degrees
Longitude-79.149 degrees
NCDEQ IdentificationORANG-005
Dam Hazard ClassificationHigh (Class C)
Dam Hazard Classification DateJuly 2011
River NameEast Fork Eno River
River Basin NameNeuse
Original Construction Date1968-1969
Dam Structural Height 40 feet (Medium Size)
Dam Normal Freeboard15 feet
Dam Crest Length1,100 feet (approximate)
Dam Crest Width16 feet
Normal Pool Elevation615 feet MSL
Drainage Area5,850 acres (approximate)
Lake Surface Area140-150 acres (approximate)

Frequently Asked Questions 
What is Lake Orange?
Lake Orange is a 150-acre surface water reservoir that is owned and operated by Orange County.  Most of Orange County’s focus is on the dam area, where we have electronic means of remotely monitoring and controlling the gates in the intake tower (i.e. the concrete structure near the dam that contains the water release valves).  It should be noted that the area around the dam is posted as a no trespassing area.  

The lake is located approximately six miles north of downtown Hillsborough.  The land upon which Lake Orange is located was donated to Orange County by local landowners and construction of the dam was funded via issuance of Orange County bonds.  

Orange County owns the property under Lake Orange up to an elevation of 615-ft. mean sea level (MSL), which is the normal pool elevation of the lake.  Lake Orange, Inc., a private development corporation, owns the recreational rights to the surface of the lake and some of the land around the lake.  Orange County also holds the rights to a flood easement across all of the property around the lake between the 615-ft. and 620-ft. MSL elevations.  The deed for Lake Orange is recorded in Book 212, Pages 362-365 of the Orange County Register of Deeds.  Many of the deeds recorded subsequently failed to properly represent this flood easement, but it exists nonetheless. 

During significant rainfall events, the lake freely “spills” at elevation 615-ft. but the overflow is constrained by a 100-ft. wide weir at the emergency spillway of the dam.  Therefore, the lake level rises during such events and “floods” in this easement area.  It is highly unlikely the lake would ever rise 5 feet to elevation 620-ft.
When was Lake Orange built?  Why was Lake Orange built?
Lake Orange was constructed in the late 1960s via a 40-ft. tall earthen dam and concrete spillway across the east fork of the Eno River. Lake Orange was built to serve as a source of water supply for local communities and Orange County residents.  

The primary purpose of the lake is public water supply for downstream users; secondary purposes of the lake include various recreational uses by Lake Orange, Inc., which they in turn lease via lake access permits. 
Why should I care about Lake Orange?
Lake Orange provides critical redundancy to regional water supply and provides year-round water flow to the east fork of the Eno River during extended dry periods.  Lake Orange serves as a partial water supply to Orange Alamance Water System (OAWS) and Resco Products Inc. (formerly Piedmont Minerals).  It is also a partial water supply for the run-of-river operation of the West Point Grist Mill and helps to ensure swimmable and fishable conditions within the West Point on the Eno City Park, owned and operated by the City of Durham.  

Although the Town of Hillsborough (Town) owns and operates the West Fork of the Eno Reservoir (WFER) as its primary water supply, Lake Orange is a direct back-up water supply for the Town.  Lake Orange is also a back-up water supply (via the Eno River) for the Town, OAWS, OWASA and City of Mebane by virtue of emergency water interconnections. 
What is an Emergency Action Plan?
In July 2011, NCDEQ classified the Lake Orange dam as a Class C (High Hazard) dam.  This classification is for “dams located where failure will likely cause loss of life or serious damage to homes, industrial and commercial buildings, important public utilities, primary highways, or major railroads.”  This NCDEQ hazard classification does NOT mean that the Lake Orange dam is at imminent risk of failure.  Because Lake Orange is classified as a High Hazard dam, an Emergency Action Plan (EAP) is required based on Federal guidelines.  

An EAP is a formal document that specifies actions to be followed to minimize loss of life and property damage in the highly unlikely event of a dam failure. Such an event is referred to by engineers as a dam “breach” and, as part of the EAP, NCDEQ requires the dam owner to submit a dam breach analysis. Those areas that become theoretically “inundated” by the dam breach inundation modeling are mapped and become exhibits to the EAP. The Orange County Planning Department maintains and updates the EAP on an annual basis. Orange County Emergency Services is the responsible party for executing and enforcing the EAP in the highly unlikely event of a required emergency response.