Lake Orange – FAQs
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.
Some residents in Orange County have properties that are located within the Lake Orange Dam "inundation zone." The "inundation zone" is the area downstream of the dam that would be flooded in the event of a failure (breach) or uncontrolled release of water. These zones are generally much larger than the area for the normal river or stream flood event. The inundation zone maps for Lake Orange can be viewed and downloaded at link below.
Updates & Inspections
The dam is owned and maintained by Orange County and is inspected regularly to ensure its safety. The Orange County Planning and Emergency Services departments have updated the Lake Orange Emergency Action Plan, which includes maps and evacuation routes for affected areas, in the highly unlikely event of a breach or failure.
Orange County Emergency Services, in conjunction with the Chapel Hill, Carrboro and OWASA, have partnered on an emergency notification system that provides almost real-time updates during emergency situations, such as extreme weather events, unexpected road closures or other issues that threaten public safety. The OC Alerts system will attempt to notify you via email, text message or phone calls. To sign up for OC Alerts, visit us on the web.
Lake Orange Maps
View the following maps to see if your residence falls within the inundation zone. Residents in the inundation zone are urged to familiarize themselves with the evacuation route for their area. In the unlikely event of a dam failure incident, affected residents will be asked by Emergency Response Officials to evacuate the affected area in compliance with the Emergency Action Plan.
- Lake Orange Inundation Zone Maps
- Evacuation Zones and Evacuation Routes - Overview Map (see Evacuation Route Maps for greater detail).
- Evacuation Routes A&B (Lake Orange Road to NC 86 and Efland Cedar Grove Road to U.S. 70 or Highland Farm Road to NC 86)
- Evacuation Routes C&D (Highland Farm Road to NC 86 or Brookhollow Road to U.S. 70)
- Evacuation Routes E, F, G, H, & I (Downtown Hillsborough Area)
For More Information: