The Governance Committee of the Platte River Cooperative Agreement

The Environmental Account of Water in Lake McConaughy

What is the Environmental Account?
The Environmental Account is the term used for a “block of water” set aside in Lake McConaughy to supplement flows in the Platte River. Water is added to the Environmental Account and stored in Lake McConaughy until the water is needed downstream. Water released from the account is tracked and protected by Nebraska water law so that the water may provide beneficial instream flows for endangered species.

Why was the Environmental Account established?
The Central Nebraska Public Power District (Central) and the Nebraska Public Power District (NPPD) have five hydropower plants in the Platte River basin that require licenses from the Federal Energy Regulatory Commission (FERC). Central and NPPD received new FERC licenses in 1998 after the original licenses expired. The establishment of the Environmental Account is required by these new licenses to address threatened and endangered species issues related to Central and NPPD operations.

How is the Environmental Account related to the Cooperative Agreement?
The Environmental Account is an important part of the Platte River Cooperative Agreement. The Cooperative Agreement was signed by the governors of Nebraska, Wyoming and Colorado and the Secretary of the Interior, in part, to address the needs of four threatened and endangered species using the Platte River by developing a Recovery Implementation Program (Program).

One of the goals of the proposed Program is to improve habitat for endangered species along the central Platte River by re-timing or adding 130,000 to 150,000 acre-feet of water per year. The Environmental Account in Nebraska, along with a Pathfinder Dam modification project in Wyoming and the Tamarack groundwater recharge project in Colorado, are expected to provide 70,000 to 80,000 acre-feet per year. The rest of the water will come from other water supply projects or water conservation programs.
One of the benefits of the Environmental Account is the ability to store and release Program water from other sources. For example, Program water can be released from Pathfinder Reservoir on the North Platte River in Wyoming and recaptured in the Environmental Account in Lake McConaughy, which is closer to important habitat along the central Platte River. The water can then be released from McConaughy when needed. Through “borrow-payback” mechanisms or other arrangements, it may be possible to use the Environmental Account to store water from other Program projects as well. “Borrow-payback” mechanisms may be used for Program water that “misses” Lake McConaughy, i.e., water from the South Platte River or water that enters the river below the lake.

Although the Environmental Account is important to the Cooperative Agreement, the Environmental Account itself will exist with or without the Cooperative Agreement or basinwide Program. Water will still be stored in the Environmental Account and released for environmental purposes because of FERC license requirements.

How much water is in the Environmental Account?
The quantity of water available in the Environmental Account varies according to how much has been added and how much has been used. Central contributes ten percent of the storable inflow to Lake McConaughy during the non-irrigation season (October through April). The amount of water contributed in this manner may never exceed 100,000 acre-feet per year. It is also possible for water to be contributed from other projects, such as the transfer of environmental water from Pathfinder Reservoir as mentioned earlier. Any water not used at the end of the year may be carried over to the next year.

In addition to regular contributions and releases, other rules or adjustments apply to the Environmental Account. First, the Environmental Account may never exceed 200,000 acre-feet, regardless of contributions or carryover. In addition, any time Lake McConaughy fills to capacity, the Environmental Account is automatically set to 100,000 acre-feet. Finally, the Environmental Account is subject to evaporation and seepage losses in Lake McConaughy in proportion to the amount of water in storage.

How is the Environmental Account used?
An Environmental Account Manager (EA Manager), an employee of the U.S. Fish and Wildlife Service, is responsible for requesting releases of water from the Environmental Account. Each year the EA Manager is required to develop a plan describing the intended use of the EA throughout the year. An Environmental Account Committee made up of representatives from various water-user entities, environmental groups, and state and federal agencies assists the EA Manager in this process. The daily operations are coordinated among the EA Manager, Central, NPPD, and the Nebraska Department of Water Resources.

Once the water has been released, the water is tracked downstream and protected by a Nebraska water right as instream flow for the central Platte River. Environmental Account water is assessed “transit losses” for evaporation and seepage along the way according to Department of Water Resources accounting procedures.
There are certain conditions that apply to the use of Environmental Account water. The most significant rule is that the EA Manager may not request releases of Environmental Account water that will cause or add to out-of-bank flooding along the river. Another condition is that Environmental Account water may be diverted through hydropower facilities, as long as the water is returned to the river.

Is the Environmental Account responsible for recent high river flows?
No. Although the Environmental Account has been established, and Environmental Account water is being stored in Lake McConaughy, there has not been any water released from the Environmental Account as of the first of April, 2000 when this brochure was published. Instead, the recent high flows have been the result of excess water in the Platte River basin, particularly in terms of high rainfall in Nebraska, mountain snowfall and water stored in reservoirs.

Where can the public obtain more information about the Environmental Account and the Cooperative Agreement?

The public can find more information about the Environmental Account by contacting the EA Manager at (308) 382-6468 or the Central Nebraska Public Power and Irrigation District at (308) 995-8601. For more information about the Cooperative Agreement and proposed Program, contact the Governance Committee’s Executive Director (toll-free at (877) 634-1773), or visit the Governance Committee’s web site at