My colleagues with the Colorado River Research Group have a new policy brief out today taking another whack at the question of “assigned water” – water kinda sorta conserved, but left in storage so water agencies can pull it out again at some future date. Think “Intentionally Created Surplus” (ICS). At this point, nearly 40 percent of the water in Lake Mead is tagged as some agency’s private storage account, rather than being available for general system use.
By so effectively propping up reservoir elevations, Assigned Water delays or completely prevents the triggering of some mandatory shortage?based curtailments spelled out in the current rules…. [T]his approach has the unintended consequence of hiding the current paucity of shared (i.e., System) water available in Lake Mead, something that will ultimately become obvious when those waters are someday recalled.
This is the issue Arizona State’s Kathryn Sorensen (one of my CRRG colleagues) has been raising, and that Kathryn (with help from Sarah Porter and I) wrote about in October. The new CRRG paper argues that, as we move toward expanding the assigned water programs available to basin water users, we need to be mindful of the risks.
Nuts!
Exactly. As I continue to watch the Colorado River drama play out, I increasingly suspect that people have not learned their lessons from the last few years, and will not do so until the next hair-raising crisis, if at all.
Since the assigned water is sitting in a reservoir with evaporative losses, perhaps the amount of assigned water should decay at a rate proportional to the reservoir losses