UC Davis Center for Watershed Sciences, October 16, 2014

The State Water Resources Control Board recently solicited public comments on how to improve its drought curtailment of water rights. Here is a summary of insights and recommendations from a group of seven California water experts.
By Ellen Hanak, Jeffrey Mount, Jay Lund, Greg Gartrell, Brian Gray, Richard Frank and Peter Moyle
This past year’s severe drought conditions meant that most users of surface water flows —agricultural, urban and environmental — had significant unmet demands. In May, the State Water Resources Control Board ordered curtailment of water rights for the first time since the drought of 1976-77 – 37 years ago.
The board followed the seniority of water rights, with riparian right-holders having first claim on the available water and appropriative right-holders following by the dates of their appropriations. Many junior appropriators were prohibited from diverting any water. With few exceptions, the board did not factor in other considerations, including the needs of fish and wildlife and public health and safety.
The experience provides valuable lessons for California, which needs to modernize drought water allocations to improve the use of scarce water resources. This will require some urgent actions for the coming year, which also may be dry.
It also behooves the state to use this experience to help establish a more robust allocation process going forward, given the increasing competition for scarce water resources in a growing state and the likelihood that droughts will occur more frequently as the climate warms and hydrologic conditions change.
In this blog, we reflect on the lessons learned from this curtailment experience and outline urgent steps the board can take to improve its regulation and management of water rights in 2015 and beyond.

To recap, the water board encountered two significant challenges in 2014 for allocating water under conditions of critical scarcity: (1) limitations in measurement and analytical capacity for surface water availability and use; and (2) lack of clarity on policies regarding factors other than water rights seniority, including protection of public health and safety and the environment. As a result, the board invoked its curtailment process quite late in the year. It also largely failed to factor in public health and safety and environmental considerations.
On a positive note, the board was able to use newly available data on surface water diversions to estimate the total demands of right-holders within river systems. These data were required under Senate Bill X7-8, one of the policy bills enacted as part of a comprehensive water package in November 2009.
This law requires all surface water users (including holders of riparian and pre-1914 water rights not subject to the board’s permitting and licensing jurisdiction) to report their diversions to the state. Using actual diversion estimates rather than the generally much higher face value of water rights made the curtailment process fairer to more junior appropriators. This new data source, though still imperfect, is an important building block for modernizing the drought allocation process.
Earlier this year, the water board commissioned a valuable experiment in developing a more formal system for determining surface water availability and allocations. The UC Davis Center for Watershed Sciences developed a pilot model of allocations on the Eel and Russian rivers, using data on flow availability from the National Weather Service and the newly available data on surface water diversions.

The effort, detailed in an Oct. 15 technical comment to the board (Lund et al. 2014), provides a promising approach for systematizing the use of data on water availability and use — so California can make the most efficient use of surface water under scarcity. This approach provides a transparent method for considering available flows and allocating water according to the priorities under state law, including seniority of water rights. The state should expand this approach as quickly as possible for California’s other major watersheds. The state also needs to begin now to address the most urgent gaps in policy and measurement.
Step 1: Modernize curtailments
If precipitation in the 2014-2015 water year is below average, the board will likely be required to issue curtailments again. To make this process fairer, more timely and more efficient, the Board should:
- Begin the curtailments planning and adjustments with a transparent technical process that forecasts full natural flow in basins are likely to seecurtailments. This process should be defined by January and updated monthly. It can rely on the expertise of the National Weather Service, which already makes routine flood-flow forecasts, and the Department of Water Resources, which assists in the forecasting. Some technical changes will be needed for low-flow forecasts. The forecasts will improve with experience. To this end, the water board should collect data to evaluate the forecasts’ accuracy.
Predicted monthly flows in Russian River basin for (a) March, (b) April and (c) May 1977. Data from National Weather Service monitoring and flows stations. Source: “Drought Curtailment of Water Rights — Problems and Solutions,” UC Davis Center for Watershed Sciences - Continue to use reported water-use information rather than the face value of water rights in guiding assignment of curtailments. Over time, the board should develop systems for cross-checking the accuracy of data reported by water users, such as with remote sensing information (as Idaho now does).
- Require larger water users to “call” their planned use. This would improve accuracy of curtailment calculations and make fuller use of available water. It can be done at the beginning of the irrigation season (March 1) for general planning purposes, and then on a more real-time basis as the season advances. Senior right-holders would include intended water transfers in their call for planned use [1].
- Build a system that accounts for both discharges and diversions, because what ultimately matters for system availability is net diversions – the amount diverted minus the amount returned to the system and available for downstream use. Building on SB X7-8’s requirement to report water diversions, the state should require large users to report return-flow volumes and locations [2]. Urban users already report discharges to the state’s regional water quality control boards. It would be fairly straightforward to require large agricultural water users to do the same, especially when they discharge through canals, pipelines and other conduits. As an interim step, the Department of Water Resources might be charged with developing a default estimation method for agricultural discharges, with water diverters specifying the locations of return flows.
- Get out in front on the curtailment process, with notifications ready by January for all surface water users, including those holding riparian and pre-1914 rights. The board also should introduce a transparent process of notifying monthly adjustments, factoring in changing water availability conditions, with the possibility of rapidly relaxing curtailments in response to improved conditions.
Step 2: Set and implement policy on water allocation priorities for public health and safety and the environment
Senior water rights holders objected to the water board’s consideration of these needs in its curtailment decisions earlier this year. Yet the board has a strong legal basis — indeed, a legal obligation — to account for these factors under the “reasonable use” requirement of the California Constitution (Article X, section 2) [3], the public trust doctrine[4], the Porter-Cologne Act, Section 106 of the California Water Code [5], Fish and Game Code section 5937 [6], the federal and state Endangered Species Acts [7], and other laws[8].

To better implement these policies in future water-rights curtailments, the board should:
- Adopt policy that narrowly defines urgent public health and safety considerations affected by water scarcity. These factors would include supplies adequate for safe drinking water, sanitation and fire suppression under conditions of urgency – an amount often thought of as roughly 50 gallons a person a day. Water allocation under this provision would need to be clearly spelled out, quantified and limited to urgent conditions, when users cannot reasonably be expected to find alternative sources in a timely way. These amounts would count against other allocations to these users. The board should then prioritize these urgent needs within the curtailment process.
- Clearly identify the priority of various environmental water uses in the curtailment process. This includes water to keep fish in good condition and to supply wildlife refuges.
- Be explicit about the priority of environmental flows and related temperatures so water right-holders can better plan ahead. Wildlife agencies should clearly identify for the board the drought flow and temperature requirements for priority river segments [9].
- Consider having a panel of outside experts rapidly review requests for relaxation of environmental standards to help inform its decision-making [10]. Granting these Temporary Urgency Change Petitions currently does not require a scientific assessment of the consequences for fish and wildlife, only concurrence of state and federal fish agencies.
- Be prepared to initiate targeted, expedited administrative or judicial proceedings to halt diversions that are both unreasonable and have high impact on water supply availability.

By taking these initial steps now, the water board will better position California to cope with a dry 2015 and future droughts. Indeed, Californians should be planning every year for the possibility of a drought, since we rarely know before the late winter or early spring what the water year holds.
Over time, this system will evolve with better measurement and more routine reporting of essential information, making it easier for all water users to plan and anticipate how to manage available supplies. One medium-term priority would be to incorporate groundwater use, especially in basins with strong connections between surface and groundwater flows.
The water board, along with state and federal government generally, has been criticized for being reactive during the drought, rather than having prepared for it. We applaud the board’s current efforts to plan for a fourth year of drought before it actually occurs.
Modernizing curtailments and setting priorities and quantities for public health, safety and the environment can be addressed relatively quickly under the current urgent conditions. If it rains this winter, these preparations will be useful for the next drought. If it doesn’t, they will help the state better manage the current crisis.
Ellen Hanak and Jeffrey Mount are senior fellows at the Public Policy Institute of California. Jay Lund, Richard Frank and Peter Moyle are professors of engineering, law and fish biology, respectively, at UC Davis. Greg Gartrell is an independent consulting engineer, and Brian Gray is a professor at UC Hastings College of the Law.
Footnotes