About Lake Levels
How do we measure lake levels?
Lake levels are a relative measure, not the actual depth of the lake. Lake levels tells us the difference between the current level of the lake and full pond. We consider full pond the point at which the water begins to spill over the flood gate or spillway. For the purposes of lake levels, we call this level 100.0 feet.
- Lake levels are updated about every twenty minutes.
- Lake levels are measured at the hydrostation dam.
- Levels are expressed in feet in relation to full pond, where full pond is 100.0 feet.
- Full pond elevation is equivalent to the top of the flood gates at gated impoundments and the top of the open spillway at lakes that do not have gates.
Lake levels fluctuate daily and seasonally due to hydroelectric generation and weather conditions. Lake levels may vary within the normal operating range, and the normal minimum or maximum elevation may occur at any time during the identified month. Lake levels may vary depending on your location on the reservoir.
We forecast appropriate lake levels according to the season, taking into consideration such factors as typical rainfall, expected power usage and others. The target number represents where we expect to be on the current date. The actual number often differs to meet current conditions.
Low Inflow Stage (LIP)
The Low Inflow Protocol (LIP) establishes procedures for reductions in water use during periods of low inflow. The LIP was developed on the basis that all parties with interests in water quantity will share the responsibility to establish priorities and to conserve the limited water supply. This Low Inflow Protocol provides trigger points and procedures for how Duke’s hydro generation projects will be operated as well as water withdrawal reduction measures and goals for other water users during periods of low inflow. As hydrologic conditions worsen, Duke will declare various stages (0-4)(NA=0) of a low inflow condition where each stage calls for greater reductions in hydro station releases and water withdrawals.
The range link shows a graph of the minimum and maximum levels over a period of time. AMSL - The term above mean sea level (AMSL) refers to the elevation (on the ground) or altitude (in the air) of any object, relative to the average sea level.
When conditions warrant, it may be necessary to operate the hydro dams or lakes in uncommon ways. Examples include during prolonged periods of heavy rainfall when the dams may be prone to spill or during dry seasons when the reservoir is not replenished in a timely manner. Check here for messages that will let you know what to expect.
Can't reach the Internet for awhile? Call 1-800-829-LAKE (800-829-5253) for lake level information.