Part One: The Colorado River and Drought: Are They Now Inseparable?
When I started this job in 2001, there was work going on related to use of water in the Lower Colorado which resulted in the Interim Surplus Guidelines, sometimes called the “Quantification Settlement Agreement” (QSA) or the “California 4.4 plan.” In essence, while this work dealt with many aspects of the lower Colorado River, one of the main things it created was a mechanism by which California could get from their then-level of use, about 5.2 million acre-feet (AF) per year, down to their apportionment of 4.4 million. It was one of the early major efforts to deal with what would become a hallmark of that basin, especially during drought, and that hallmark is use in excess of current supply.
With that as the opening bell, for purposes of this article, the 2000s then followed with continued work by the states, our federal counterparts and other stakeholders on the river, including Mexico, on several other fronts.
In 2004 and 2005, we could see that the drought was jeopardizing uses relying on Lakes Mead and Powell, and some mechanism was needed by which demands could be reduced to protect lake levels.
The resulting product came to be known as the “Interim Shortage Guidelines” or “Coordinated Reservoir Operations.” This work embraced a couple of major concepts – instituting shortage criteria in the Lower Basin, whereby those states could agree to take or share shortages at critical reservoir elevations, and all seven Colorado River Basin States agreed to operating Lakes Mead and Powell more in concert with one another.
It also created what is called “ICS,” or “intentionally created surplus,” which allowed the lower states to conserve water and bank it in Lake Mead for later use. Allowing such carryover not only reduces demand, it keeps Lake Mead higher – which is important if you are Southern Nevada Water Authority and your municipal intakes are at risk or if you use power generated at Hoover Dam.
Most recently, Minute 319 of the Mexican Treaty provided for a number of things, but the two most pertinent for today’s article are recognizing Mexico’s ability also to conserve and bank water in U.S. reservoirs, known as ICMA, or Intentionally Created Mexican Allocation, and the recognition that Mexico might have to see a shortage, too, under certain conditions. In this way, Mexico is allowed to conserve and protect some of the water due it under the 1944 treaty, but it also may face shortages just like everyone else in the basin.
The common themes to the three episodes described above are they all show the flexibility of the Law of the River; they all show that the basin states, working with Reclamation and the International Boundary and Water Commission (IBWC), can provide solutions to very thorny questions; and they show how drought and undampened use can wreak havoc in such a large, diverse river basin if left unaddressed. They also exemplify what can be accomplished when strong, productive relationships exist in and among the basin states and our federal stakeholders, all of whom know that comprehensive technical and administrative solutions outperform litigation any day of the week.
I want to visit about the next real issue facing the basin now, but it seemed appropriate to first set the stage by showing above how the basin water managers and stakeholders have successfully met previous challenges. And that next real issue is not that different from the first three, either, in that it deals with drought and its impacts.
The fact is that even with all the work just described behind us, drought still threatens the basin. Even with QSA, coordinated reservoir operations and Minute 319, Mother Nature can still throw the basin a curveball with low runoff, which will still depletes Lakes Mead and Powell despite the basin’s current management schemes. Even with all we’ve done, there’s more to do.
By mid-2013 we could see that if the low runoff of 2012-13 continued into 2014 and 2015, we’d be in the same position as 2004-05, when we risked losing the ability to generate hydropower at Lake Powell within about 18 months due to drought. That’s the simple hydrology lesson – moving water out of Powell to do any number of things, while inflows are low, simply drives its level down.
So what? Well, Lake Powell bestows a list of benefits upon the State of Wyoming that we might not even see because of its location. To name a few, its primary purpose is to make sure we meet the non-depletion requirement of the Colorado River Compact, which says the upper basin cannot deplete the flow at Lee Ferry, Ariz. below an aggregate of 75 million acre-feet for any 10 consecutive years, or we violate the Compact.
When runoff is paltry, we’ve always met that obligation using Powell’s storage to make up the difference. And, if we fall below the outlet tubes and Powell has no usable storage to speak of, we risk long-term Compact problems because it would be difficult to climb back above the 75/10 threshold.
This is part one of a two-part column by State Engineer Pat Tyrrell. In the second part of his column, Tyrrell discusses the importance of hydropower revenue, the responsibility for water and ways we can address water shortage concerns.