Water Management Committee Meeting

The Water Management Committee (Water Committee) meeting began at 1:00 p.m. at the Fish and Wildlife Service Office in Denver, Colorado. The Chairman, John Lawson, reviewed with the Water Committee the pre-proposal meeting held January 23, 1998.

Conflict of Interest was discussed with the consulting firms. At that meeting, the consulting firms inquired if the general criteria the Selection Committee will use to evaluate the proposals would be made available to the consultants as reference for proposal preparation. Mr. Lawson indicated that the criteria would be provided to the consulting firms in two weeks. The Selection Committee members present were asked to provide criteria to him by Wednesday, February 4, 1998. The Water Committee members were also invited to provide criteria as well. It is anticipated that the criteria will be sent to the consulting firms on Friday, February 6, 1998.

The State of Colorado requested a copy of Nebraska's Water Conservation/Supply Notebook (notebook). The U.S. Fish and Wildlife Service (FWS) and U.S. Geological Survey (USGS) also needed copies of the notebooks. Copies of the notebooks will be made and provided by Mr. Lawson.

The agenda for the meeting included the Milestones W14-1 and W15-1. The Water Committee discussed the first bullet item under W14-1, which identifies the need to determine existing flow conditions in the associated habitats and at the state lines. The discussion focused on what the Water Committee needs to provide the consultant with respect to existing flow conditions. After lengthy discussion and for the purpose of the water conservation measures evaluated by the consultant, the "existing flow conditions" are defined as the historic hydrologic conditions that occurred for the 20-year period from water year 1975 through 1994. The existing monthly flow conditions will be summarized and provided to the consultant. The existing flow conditions will be used to analyze trends, identify periods of excess and shortage, and establish dry, wet, and normal flow conditions for comparative purposes. The 1975 through 1994 period adequately represents wet and dry cycles in the Platte River System, while reflecting near present day development and reduces the time needed to screen water conservation alternatives. Jon Altenhofen has already begun investigating the existing flow conditions and was asked to provide his information to Mr. Lawson prior to the next meeting, so it can be copied and distributed to the other Water Committee members for review before the next meeting. The Water Committee also discussed with the Platte River EIS Office representatives present how the 1975 through 1994 time period would fit with their work.

After a short break from 3:55 to 4:00 p.m., the Water Committee discussed the lag and gain/loss factors mentioned in the second bullet of Milestone W14-1. The term lag relates to the travel time of the water from point to point in the system and is less important in monthly modeling. The lag factors will be used in a daily accounting system. Colorado estimates the lag factors on the South Platte River at approximately one day between Water Districts with three (3) districts between Denver and the Colorado-Nebraska Stateline. The actual gain/loss factors for sections in the river can be calculated using the historic monthly data (1975-94). The gain/loss factors account for evaporation, phreatophytes, recharge to ground water, wells, etc.

The difference in accounting for the Platte River Basin with respect to the three states was discussed. In the North Platte River system, set loss factors are charged against storage water in the river based on the ratio of storage flow to the total flow at difference points. Storage flow in the South Platte River can be charged a shrink of about ½ % per mile, depending on river conditions. If the river bed is dry, a higher loss is charged.

Water conservation measures were discussed. Conservation activities tied to storage water can be credited to the Program and can be protected to the state lines. Conservation activities that reduce the consumptive use of natural flow diversions would provide more water in the river that would be diverted by junior appropriators, unless a means to protect that historical consumptive use of a natural flow diversion could be obtained by water law changes. In the State of Colorado, an irrigator owns his consumptive use water and can market it with certain limitations. That ability does not exist under the water laws of Nebraska and Wyoming.

The Water Committee Chairman made the following assignments to the states:

- Provide to the chairman methodologies for protecting water from point "A" to point "B" within their respective states; and

- Define what can be done under existing water law to protect a delta consumptive use of natural flow water.

Lastly, the Water Committee discussed bullet item No. 3 under Milestone W14-1 regarding hydrologically connected ground water. The consultant for the Water Conservation/Supply Study needs to have information regarding the hydrologically connected ground water for the entire Platte River Basin. The hydrologically connected ground water is applicable to both wells and return flows from surface irrigation and is important for determining how and when water returns to the river system. Jon Altenhofen suggested using the Streamflow Depletion Factors (SDF) maps to estimate return flow response to the river. The State of Colorado has used the SDF maps with good results. Some concerns regarding the SDF maps and their usefulness were expressed by Ann Bleed and Duane Woodward. A technical paper regarding ground water depletions using the SDF techniques was provided to the Water Committee members for review.

The draft Peer-Review Guidelines being developed by the Technical Subcommittee on Monitoring and Research was handed out and Mr. Lawson asked the Water Committee members to be prepared to discuss the guidelines at the next meeting.

The next Water Committee Meeting was scheduled for February 27, 1998, and will be held in Denver, Colorado, from 9:00 a.m. until 3:00 p.m. In the future, the meeting dates will be announced to all Water Committee members via E-mail to provide more time for the Water Committee members to make travel arrangements. The meeting adjourned at 5:25 p.m.