2000 WY EA AOP

• File Number: 8461.450
• Description: EAC/RCC
• State: CO
• Basin: South Platte
• Water Division: 1
• Date: 3/6/2000
• Author: Sharon Whitmore ‎(EA Manager)‎
• Title: 2000 WY EA AOP
• Water Supply Pro - Doc Type: Correspondence

The proposed Program will be administered using an adaptive resource management (ARM)
approach. Using this approach, effects of Program activities on the associated habitats and
responses of the target species to those effects will be monitored and evaluated during the first
increment of the Program. Based on information obtained through the Program's monitoring and
research component, actions and/or adjustments may be identified and implemented, consistent
with the purposes of the Program.
A Cooperative Agreement (CA) was signed by the states of Nebraska, Wyoming, and Colorado
and the Department of the Interior on July 1, 1997, to pursue this effort. The CA will remain in
effect for three years or until the signatories enter into an agreement implementing a Program
following completion of National Environmental Policy Act (NEPA) and Endangered Species
Act (ESA) processes, whichever occurs first, or until the CA is terminated by the signatories.
The CA also includes provisions for a potential six month extension. It is understood that
operations of the EA will eventually be integrated as part of a future basin-wide Program.
Service-recommended target flows will serve as the initial reference point for determining
periods of excess and shortage in the operation of Program reregulation and water
conservation/supply projects, until such time as new information becomes available which
indicates modification is warranted. Recommended target flows are described in detail in the
Service's "Instream Flow Recommendations for the Central Platte River" (May 23, 1994) and
"Pulse Flow Requirements for the Central Platte River" (August 3, 1994) and summarized in
Table 1.
This EA AOP outlines the Service's general intentions for operation of the EA in the 2000 water
year. Changing hydrologic conditions and other considerations may require a change in the
guidelines described in this AOP.
SUMMARY OF PREVIOUS WATER YEAR OPERATIONS
As of October 1, 1999, the Districts are required to determine Predicted Storable Natural Inflows
(PSNI) and Water Year-Type (very wet, wet, transitional, dry, very dry) by October 15 of each
year. These predictions establish certain reservoir operating rules during the non-irrigation
season (see Appendix A).
The Districts were not required to provide predictions to the Service until October 1, 1999;
however, a prediction was provided to the EA Manager on October 22, 1998, as a practice
exercise. The Districts' PSNI for October 1, 1998, through March 31, 1999, was 471,000 af.
The combined value of Lake McConaughy content (1,239,900 af) and the PSNI was 1,710,900 af
which categorized the 1999 Water Year as a"Transitional Year." A revised prediction, provided
in December of 1998, changed the PSNI slightly but did not change the predicted water year
type. Lake McConaughy's peak and end-of-September elevations were greater than initially
projected in the District's 1999 Water Year Operations Plan. Figure 1 depicts flows at Grand
Island in 1999.
EA AOP 2 January 31, 2000