DRAFT Minutes
Water Management Committee Meeting

The WMC Chair reviewed the revised agenda for the meeting and identified the discussion of the Depletions Plans would focus on each state giving examples illustrating how their plans would work.

Jim Cook led the discussion of examples for the Nebraska Depletions Plan. The State of Nebraska will offset depletions to the target flows and state protect flows (existing water users) for the transition period from July 1, 1997 through December 31, 2005 (start of the Program). Nebraska has compiled land use inventories as of 1997 to quantify the irrigated acres and crop types in the basin. The land use inventories were developed using satellite imagery and information from the Farm Services Administration (FSA), with some ground truthing. This baseline land use data has been incorporated into the Cooperative Hydrology Study (COHYST) modeling for each reach modeled to establish existing water use as of 1997. New and expanded groundwater use will be determined using the COHYST model to examine changes in consumptive use in each reach from increased irrigated acres or changes in crop types to identify affects to the river. The COHYST model reaches are typically defined for existing gaging stations location and includes tributaries. The COHYST model will be used to create monthly graphs or look up tables for each reach/tributary to estimate the amount, timing and location of any depletions to state-protected flows and target flows.

An example of a depletion occurring in the river near Scottsbluff was discussed. If the depletion affected a state protected flow, the depletion would be replaced at a point about above where the state protected flow would be impacted to keep the river whole. If only a target flow was affected, the depletion’s affect at the habitat would be replaced. It was noted that the COHYST model only quantifies affects to the given river reaches/tributaries and does not quantify affects to the Central Platte Habitat or water appropriated along the way. These affects have to be routed through the river system and a methodology to quantify the affect has not been developed. Transit loss factors that include affects of diversions to route unprotected water through the system in Nebraska need to be developed. It was noted that conveyance loss factors (evaporation and seepage) for the South Platte River water administration have not been finalized. Methodology to determine depletions to state protect flows and target flows are yet to be developed.

The COHYST model does handle acres with both surface water and groundwater sources. The modeled crop Consumptive Irrigation Requirement (CIR) is met using the surface water source first followed by the ground water source to give a full CIR. A full CIR assumed in the modeling is typically about 90% of the potential crop evapotranspiration (ET). The model takes into account the variability in surface water diversions so in years when surface water is more abundant, the groundwater needed to meet the CIR is less.

As an example, if 40 acres of irrigated land with commingled water in the Nebraska Panhandle area were in operation prior to 1997, the 40 acres are part of the baseline. If a new well is added after 1997, a well permit would be required. When the new well permit is considered, it will be determined if the 40 acres was already receiving a full supply. If the new well was determined to provide a full supply, then an increase in consumptive use would be shown and any depletions to state protected flows and target flows would be replaced. However, if the 40 acres had been previously getting a full supply, the well would be assumed not to cause an increase in consumptive use.

Beginning on January 1, 2006, individual water users will be required to offset adverse effect on state protected flow, with the state offsetting any incremental depletion to the target flows. The obligation during the Program related to groundwater is to replace depletions occurring within the 28%/40 year line. Use outside the 28%/40 year boundary will be monitored by Nebraska and reported to the Governance Committee. Within the 28%/40 year lines impact zones will be determine to group area of similar characteristics. This would allow for lands within the same zone to be retired to bring other land in the zone into production with no net affect.

By January 1, 2007, the state will have determined new depletions to target flows in the transition period (July 1, 1997 and December 31, 2005). By December 31, 2008, the state will describe the offset measures in place or planned to offset for those depletions. Sources for offset water are identified in the depletions plan. If a source of offset is a Program Water Project that is not on line, then there may be some delay in providing offset water. Depletion offset will be provided from the time offset sources are available without respect to past depletions to target flows.

Following a lunch break from 12:00 to 1:00 p.m., the meeting resumed with examples for Wyoming’s Depletions Plan presented by Mike Purcell. For irrigation above Guernsey Reservoir, the baseline is set by the Modified North Platte Decree with respect to caps on irrigated acreage and consumptive use. For the Laramie River, Horse Creek, and below Guernsey Reservoir there is a second baseline based on historic irrigated acreage. If the second baseline would be exceeded, depletion offset would likely be provided in September from water available from the Pathfinder Wyoming Account or another source.

An example of an industrial use near Saratoga was discussed. Under the Wyoming Plan, the project proponents would be responsible to determine the depletion at the site. The depletion could then be replaced 1) at the point of depletion; 2) at the Wyoming/Nebraska state line; or 3) replaced at the Wyoming/Nebraska state line with respect to the depletion to the target flows. Options 2 & 3 would required an analysis to determine what would have happened to the depleted water had is stayed in the system. No methodology or tool exists to conduct such an analysis at this time. If an analysis identified a depletion of 10 acre-feet (af) at the state line with a depletion of only 2 af to target flows, Wyoming would only offset the 2 af depletion to the target flows. There was disagreement between Wyoming and Nebraska on the quantity of depletion to be replaced at the state line in this example. Nebraska will only protect water that is provided for Program benefit. There was considerable discussion on the fate of Wyoming replacement water within in Nebraska.

On the Laramie River, there are flow requirements associated with Grayrocks Reservoir that Wyoming does not what to affect. It is anticipated that depletions will be limited such that changes to the flow requirement will not be triggered. Additional information would be needed to analyze depletions on the Laramie River.

Colorado discussed their North Platte Depletions Plan. North Platte depletions would be assumed to occur at the Colorado/Wyoming state line regardless of location. These depletions would be routed through Wyoming and Nebraska subject to whatever method is developed to determine affect on target flows with the replacement provided at the Colorado/Nebraska state line via Tamarack. Colorado is proposing a cap of 2,500 af of North Platte depletions that will be replaced at Colorado/Nebraska state line before seeking Governance Committee approval.

Colorado reiterated their support for the use of the transit loss factors developed for the Reconnaissance Study in the South Platte Plan for routing unprotected flow. However, they will go back to the original loss factors in the 1997 Cooperative Agreement, until Wyoming and Nebraska have resolved how they will handle unprotected water within their states. The original loss factors are the values used in Colorado water administration.

Colorado noted that they are continuing discussions with the Fish and Wildlife Service (FWS) to clarify language regarding the 121,000 af. Colorado noted that they have received a number of comments regarding the effect of the Forest Service Vegetation Management Plan on peak flows.

In response to questions regarding how the Federal Depletions Plan will handle federal incentive programs such and the Natural Resource Conservation Service’s (NRCS) EQIP program, Don Anderson indicated that since this program benefits individual water user in each state it is not covered by the Federal Plan, as the plan is to cover depletions for activities with a “national” benefit. He indicated that the FWS is working with the NRCS regarding the need for the NRCS to consult on such programs and the FWS will be meeting with the NRCS in the near future to further discuss the consultation process.

Prior to close of the meeting, the Executive Director asked the WMC what other items the committee needed to complete before a program could be implemented. It was identified that the certain appendices in the FWS’s instream flow recommendations document need to be discussed by the WMC. The FWS will provide the document to the WMC and the WMC will offer input to the FWS.

The states will meet to discuss development of transit loss factors. The initial state’s meeting will be a conference call on August 17 at 9:00 a.m. mountain time to be arranged by Steve Sims.

The next WMC meeting was scheduled for October 6, 2004. The meeting will be held from 9:00 a.m. to 4:00 p.m. mountain time at a place near the Denver Airport.

The meeting adjourned at 4:00 p.m. Mountain Time.