Three consecutive years of drought have depleted California’s water storage, brought hardship to the agricultural sector, and led to stringent emergency conservation measures in cities throughout the state. In October, the National Oceanic and Atmospheric Administration released its outlook for next winter, and the preliminary modeling suggests more of the same. So what, if anything, should the state do differently next year?
The State Water Resources Control Board, which administers water rights in California, is asking this very question. In May of this year, the board limited surface water diversions (a process called “curtailment”) for thousands of water users for the first time since the 1976–77 drought. The board followed a century-old system that cuts back diversions based on the seniority of the water right. During curtailments, this system—often referred to as “first in time, first in right”—gives priority to those who have the longest history of water use or those who have property that lies along a river. Few, except perhaps those who were not asked to cut back, were happy with how this process went, so the board sought input on how to improve water allocation next year.
In collaboration with a number of our colleagues, we made recommendations to the board for improving the efficiency and fairness of the curtailment process. Our letter, posted in full on the UC Davis Center for Watershed Science’s Californiawaterblog.com, makes the following recommendations:
Modernize curtailments. Last year’s approach was based upon limited information about available flows and water use. Because of this, the board was forced to curtail whole groups of water users, rather than identifying individual users based on their seniority. For example, on many rivers the board curtailed everyone who had a water right that post-dated 1914, the year our modern rights system was established. In the coming year, the board can significantly improve curtailments by taking advantage of existing tools that forecast flow and estimate location and amount of use.
In addition, this year the board did not undertake significant curtailments until late May, more than two months after the irrigation season began. We recommend that the board announce curtailments much earlier in the year so that water managers can better plan to seek alternative supplies or implement additional conservation actions.
Clarify policy on the environment and public health and safety. This year, the board, with some minor exceptions, chose not to specify the amount of water that should be set aside to protect public health and safety, nor did it set priorities for trade-offs between meeting environmental needs and satisfying water rights. If, as predicted, 2015 turns out to be dry, the board will need to confront these issues head on. We argue that the laws governing water use require the board to set and implement policies on these issues. In addition, we recommend that the board create an independent scientific advisory panel that would help to inform decisions about environmental trade-offs.
These changes will be useful, even if it rains this winter. Recurring droughts are a part of California’s climate, and by modernizing how we allocate our water resources during times of scarcity we can be better prepared for the coming year—and future droughts.