Just one day after six of the seven states submitted their proposal to the Bureau of Reclamation, California snuck in under the BOR’s January 31 deadline and submitted its own to address systemic shortages for use of the Colorado River.  In its plan, that state openly acknowledges it couldn’t come to a consensus with the other states, largely because it felt it would give up too much, when under the existing legal framework, California has the most to lose. 

And yet, California’s plan is quite similar in many ways to the one it rejected from the other states, at least in terms of its basic elements.  Both plans call for cuts starting when Lake Mead falls below 1145, and then progressively greater cuts as the lake drops from 1090 down to 1000.  Both plans seek to protect minimum surface elevations in both Lake Mead and Powell (1000 and 3500, respectively) in order to preserve the power generation capabilities of their respective dams, and in the case of Lake Powell, to ensure deliveries to the Lower Basin.  Both plans envision increasingly larger water use cutbacks as Lake Mead falls, ultimately up to about 3.3 maf when the surface elevation of Lake Mead drops to 1000.  Both plans essentially accept that the Lower Basin carries the brunt of responsibility for cutbacks.

So what was the problem?  Why couldn’t California agree?  It’s all in the details of how those responsibilities would be shared, and the magnitude of overall cuts when Lake Mead is above 1030.  Under the Six State Plan, it’s California that would have to cut back the most—anywhere from 0.77 to 1.42 maf, depending on how low Lake Mead drops.  Arizona is next in line, with cuts up to 1.25 maf.  But under the California plan, those two states swap positions of responsibility—Arizona would have to cut the most.  It’s a little unclear exactly how much, because the California proposal was not detailed enough to definitely determine the state’s relative responsibilities, but it appears that Arizona might have to cut as much as 1.6 maf if Lake Mead approaches a low water mark of 1000.  California would likely face cuts only up to about 1.3 maf.

Even in better times, when Lake Mead is between 1090 and 1145, under the California plan Arizona would still carry the lion’s share of cuts—0.56 maf, compared to 0.40 maf from California.  The California proposal would also shift some of the burden to reduce away from Mexico, and place most of that on Arizona.  

In summary, the California Plan envisions cutting back about 0.1-0.3 maf less than would happen under the Six States’ plan, with Arizona taking up to and additional 0.15 to 0.4 maf in cuts.  Nevada’s share would be similar under the two proposals, although marginally higher under California’s plan.  Mexico would be a big winner under the California plan, having to cut back about 0.3-0.4 maf less than under the Six States’ plan.

Then there’s the magnitude of overall cuts, especially when Lake Mead is above 1030 (as it is today).  It varies, but under the Six States plan, the overall Lower Basin cutback would be about 0.7 maf greater than what California proposes for any given surface elevation.   

Notably, California argues that it has already given up substantial potential water use that it once relied on, including a permanent reduction in 0.8 maf as part of the 2003 Quantification Settlement Agreement and associated agreements.  In other words, it wants to be given credit for past actions that have already eroded some of its original legal advantages over its neighbors.

Besides the substance, the California plan carefully excludes the word “evaporation”, and makes no mention of its possible role in the Lower Basin’s responsibility for this loss in the system.  Unlike the Six States’ plan, which explicitly identifies a potential loss of over 1.5 maf that would be taken from the Lower Basin’s share of future water use, the California plan is silent on the topic, possibly to avoid giving up a negotiation point with the Upper Basin, which already accounts for evaporation in its use totals (since it affects water delivery to the Lower Basin).  In contrast, the Lower Basin currently does not, since the evaporation occurs in the system before reaching the Lower Basin states.  Arizona and Nevada appear to be ready to concede the point, while California is apparently not.

Instead, without connecting this to evaporation, California proposes a 1 maf cutback whenever Lake Mead is below 1145, to be shared among the three states, with California on the hook for 400,000 af—notably less than Arizona’s share of 560,000 af.  This is in sharp contrast to the Six States’ plan, which would assign California over half of the 1.5 maf total to explicitly address evaporation, while Arizona would be responsible for cutting considerably less. 

Tables 1 and 2 summarize the potential cuts assigned to each state and Mexico by the California proposal, and compares them to those under the Six States’ plan.  The numbers for the California proposal should be considered estimates, because that plan does not explicitly assign responsibility to the states for some of the cuts proposed.  That said, the tables provide a useful rough comparison between the plans.

Overall, the message from California appears to be that it’s not ready to give up its advantageous legal position relative to water rights and use under the existing 1922 Compact and subsequent actions that comprise the Law of the River.  It is deliberately vague in some respects, for example on the question of how to account for evaporation in the Lower Basin, or how to assign responsibility with its neighbors for the more drastic cuts it proposes when Lake Mead falls below 1030.  Should it be proportionally?  Or some other method?  And then there’s the question of the Upper Basin’s responsibility.  The Six States’ proposal treads lightly on this topic, but California is more explicit, calling for conservation and drought operation releases from the Upper Basin that would amount to 1 maf added to the system when Lake Powell drops below 3550 (as it is today).  The Six States proposal does not quantify potential Upper Basin actions.

This all appears to be leading to either a protracted negotiation between the states, federal intervention, or a series of lawsuits.  The strong early returns on the snowpack from this winter suggest the states and BOR may have bought some time to sort this out, but not enough to avoid the hard work still in front of them necessary to avoid potential disaster that would affect all of them.