Members of the Colorado River Research Group, scholars who study the basin, have a useful new report out today (pdf here) urging a more unified approach to the currently fragmented environmental management initiatives on the Colorado River. It describes “an incomplete patchwork of largely uncoordinated efforts, existing in some cases to facilitate compliance with environmental laws that might otherwise constrain users from withdrawing additional water from the river system.”

In other words, the driver isn’t really the environment, so much as managing the problem of environmental values getting in the way of taking water out of the river. This is where the strange accretions of our water management law have left us.

At the heart of current Colorado River management are laws, policies, dams, and aqueducts that divide the flow of the river into many discrete allocations and rights. The current strategy is politically motivated by the desire to minimize interstate and binational competition for limited watersupplies, while simultaneously empowering states and local water managers with the legal certainty and autonomy necessary to support the management of their water allocation. Environmental programs evolved later around this pre?existing framework, with most efforts focused on modifying the operations, or mitigating the impacts, of the basin’s physical infrastructure. An unintended result is a framework that often impedes the search for coordinated management strategies.

The key takeaway message from the “Law of the Colorado River” conference I attended a couple of weeks ago in Las Vegas: it sucks to be the junior user on an over-appropriated river system. Under the doctrine of prior appropriation, the guiding principle for western U.S. water management, “senior” water uses/users – those that have been extracting water the longest, have the highest priority when water gets scarce. Those are usually farms. “Juniors” – those who came later, primarily cities – have a share that is generally smaller, and that is at greater risk as supplies run short.

In California, for example, the Metropolitan Water District, which has a smaller share of water that is also junior to the big farm districts of Palo Verde and Imperial. Met is rich and politically powerful, but this is one of the great examples of how water doesn’t simply flow uphill toward that money. It sucks right now to be Met.

Arizona is junior in a bigger way, because the cities of central Arizona came to the party even later, so they’re junior to all of California’s uses.

A lot of the jockeying right now involves coming to terms with that problem.

But the CRRG report is a reminder that the environment is the ultimate junior.