The draft Colorado River Risk Study, commissioned by the Colorado River District and other West Slope parties, forecasts that if another drought like 2002-04 recurs, Lake Powell, now about half full rather than full as it was then, could fall below power generation levels or be drained unless Drought Contingency Plans (DCP) can be put in place.
Should the worst happen, Colorado and its sister Upper Division states (Utah, Wyoming and New Mexico) that are party to the Colorado River Compact of 1922 would be hard-pressed to meet compact obligations to the Lower Division states (California, Nevada and Arizona).
The draft Risk Study is now in Phase II, which is a technical process to learn if federal and state Colorado River computer models can be used conjunctively to better predict what could happen in the state of Colorado. Other partners in the study are the four West Slope Basin Roundtables (Colorado Basin, Gunnison, Yampa-White and Southwest) and the Southwestern Water Conservation District– with assistance from the Colorado Water Conservation Board.
At its quarterly meeting on Oct. 17, the Colorado River District Board received an update on the work. John Carron of Hydros Consulting, the study contractor, said the takeaways from the study so far are:
• Should a drought on the order of 2002-04 recur with Lake Powell at its current half-full level, hydroelectric power generation is jeopardized;
• Hydrology, demands and future development levels matter — the higher the consumptive use in the Upper Division states, the higher the risk to existing users;
• The most successful Drought Contingency Planning requires joint participation by both Upper and Lower Division states;
• Drought Contingency Planning is essential;re-operations of reservoirs, such as Flaming Gorge, to move water down to Powell reduces the risk, but in more severe droughts (e.g., 1988-1993 and 2001-2005), demand management (reduced water use) would be necessary in addition to any
• Some of the volumes of demand management that the model is forecasting are large and may not be feasible, thus the need to consider the trade-offs and alternative strategies;
• Demand management combined with a water bank could limit the impact by spreading conservation over many years and providing greater control over conserved water — a must-have condition.
The four West Slope Basin Roundtables called for the Risk Study at a joint meeting held in December 2014 in order for the West Slope to better understand the risks to current water users of future water development and how development, basin by basin, might look against the risk. As Colorado River water is also used on the Front Range of Colorado, drought risk is important to Front Range Roundtables and their future development, but they opted not to participate in the study.