Report 2022-106 All Recommendation Responses

Report 2022-106: Department of Water Resources: Its Forecasts Do Not Adequately Account for Climate Change and Its Reasons for Some Reservoir Releases Are Unclear (Release Date: May 2023)

Recommendation #1 To: Water Resources, Department of

To ensure that its B120 water supply forecasts are as accurate as possible, DWR should implement a forecast verification process by November 2023 that includes the following:

1. An annual evaluation of the accuracy of each of its monthly forecasts using multiple means in accordance with best practices, including an assessment of whether actual runoff fell within its probability range and an assessment of the accuracy of its median forecast.

2. Identification of the likely causes of greater-than-expected forecast errors.

3. An annual assessment of opportunities for improvement and enhancement, including identifying and evaluating available and emerging forecasting technologies.

4. The development and implementation of plans to improve its forecasts based on the findings from its annual evaluation.

5. Annual reporting on its water supply forecasting web page about the above actions so that the public is aware of the steps it is taking to improve and enhance the accuracy and predictive capability of its forecasts.

6-Month Agency Response

The implementation of improved forecast models, including the adoption of new and emerging technologies, is currently under development and will be implemented over a series of several years.

The Department of Water Resources (DWR) currently posts forecasting information on the California Data Exchange Center (CDEC) website (https://cdec.water.ca.gov/snow/) where forecast assessment data are available within Bulletin 120.

In addition, DWR will launch a new public website for the California Cooperative Snow Surveys Program (https://snow.water.ca.gov) in November 2023. The website will display regional and statewide snowpack conditions and include dashboards that provide water supply forecast verification, water supply data, and forecast comparisons.

The website will also include an annual evaluation of forecast accuracy and documents areas for improvements and implementation plans such as the Roadmap for a Climate Resilient Forecasting Framework (https://water.ca.gov/roadmap) for these improvements.

Additionally, DWR continues to expand information and data available on its existing public-facing website, California Water Watch (cww.water.ca.gov.) The site is a comprehensive resource for drought and precipitation information and is promoted to the public, media outlets, and interested parties on a regular basis.

California State Auditor's Assessment of 6-Month Status: Pending

60-Day Agency Response

The implementation of improved forecast models, including the adoption of new and emerging technologies, is currently under development and will be implemented over a series of several years.

The Department of Water Resources (DWR) currently posts forecasting information and tools on the California Data Exchange Center (CDEC) website (https://cdec.water.ca.gov/snow/) where forecast assessment data are available within Bulletin 120. In addition, DWR continues to perform forecast variance analysis annually.

California State Auditor's Assessment of 60-Day Status: Pending

Recommendation #2 To: Water Resources, Department of

To ensure that its water supply forecasts better account for the observed effects of climate change as soon as possible, DWR should continue to implement its plan to adopt an updated water supply forecasting model and updated procedures. By November 2023 DWR should also do the following:

1. Publish on its website a timeline affirming when it will implement its updated model and procedures across all of the watersheds for which it produces a water supply forecast.

2. Establish and publish the specific criteria that it will employ to determine when its updated model has demonstrated sufficient predictive capability to be ready for use in each of the watersheds.

3. Provide annual updates on its website regarding the status of its implementation of the updated model and procedures.

60-Day Agency Response

In March 2023, DWR adopted the Roadmap for a Climate Resilient Forecasting Framework (Roadmap) that includes annual forecast modeling assessments, latest developments, and achievements. The Roadmap is publicly available on DWR website (Link: https://water.ca.gov/roadmap) and is a working document and will continually be updated.

DWR publishes a Hydroclimate Report and presentations on annual forecasting assessment that includes observed effects of climate change on the Department's California Data Exchange Center's website. The next Hydroclimate Report will be available in April 2024 for the previous water year.

California State Auditor's Assessment of 60-Day Status: Pending

DWR posted the Roadmap on its website, however, as we discuss in the text of the report, the Roadmap does not yet include accountability mechanisms to ensure that it implements its new model promptly. Further, although the plan includes the objective of developing forecast model performance tools, it does not contain specific criteria for determining whether the new model is sufficiently accurate for use or a timeline for implementation. We look forward to following DWR's progress in implementing its planned updates to its forecasting methodology in future updates.

Recommendation #3 To: Water Resources, Department of

To better prepare to effectively manage State Water Project operations during future, possibly more extreme drought periods, DWR should, by May 2024, develop a long-term plan for proactively mitigating and responding to the impacts of drought on the project. In accordance with drought preparation best practices, DWR should include the following components in the plan:

1. An assessment of the potential impacts of drought on the State Water Project that accounts for the possibility that climate change may result in more severe droughts.

2. An assessment of DWR's current capability to address those potential impacts, as well as the identification of any steps that DWR must take to gain needed capabilities.

3. Specific strategies for operating the State Water Project to mitigate and respond to the identified impacts of drought while still achieving the project's objectives.

4. A description of the circumstances that would trigger DWR to begin implementing its drought response strategies.

5. Provisions requiring DWR to update the drought plan at least once every five years and also after each drought to incorporate lessons learned.

6-Month Agency Response

DWR continues to compile existing and new drought information into a comprehensive long-term document for the SWP.

California State Auditor's Assessment of 6-Month Status: Pending

60-Day Agency Response

The Department of Water Resources is compiling existing and new drought information into a comprehensive long-term document for the State Water Project.

California State Auditor's Assessment of 60-Day Status: Pending

Recommendation #4 To: Water Resources, Department of

To ensure that it can demonstrate effective oversight of State Water Project operations and efficient use of the project's water supply, DWR should, by May 2024, develop and implement a policy and set of procedures for documenting the following:

1. Its monthly and annual plans for operating the State Water Project, including the amount of water that it intends to release, store, and export.

2. The rationale behind its plans and an explanation of how the plans will help it to achieve the project's objectives.

3. A description of any changes that it makes during its operations that deviate from its plans.

4. The rationale for any changes that it makes, including the conditions that led to the change, the specific reason for the change, and any viable alternatives that it considered.

5. The degree to which it succeeds in achieving each of the project's various objectives on a monthly and annual basis.

6-Month Agency Response

DWR continues to develop a policy to further document its practices and procedures related to water operations. DWR has implemented the use of a new internal operations report to enhance documentation of the rationale for operations and changes to those operations. DWR is on track to implement Recommendation No. 4 by May 2024.

California State Auditor's Assessment of 6-Month Status: Pending

We look forward to evaluating DWR's implementation of this recommendation when it provides its new policy and procedures as well as examples of its internal reports demonstrating that it has implemented each element of the recommendation.

60-Day Agency Response

The Department of Water Resources (DWR) will enhance our formal documentation on the development of SWP water supply planning studies procedures as well as the rationale for real-time operating procedures. DWR is exploring alternative methods to make this information publicly available.

California State Auditor's Assessment of 60-Day Status: Pending

Recommendation #5 To: Water Resources, Department of

To ensure that its operation of the State Water Project reflects the possibility of more extreme climate conditions, DWR should, by May 2024, evaluate the data and information that it relies upon in its monthly and annual planning for its Lake Oroville reservoir operations, including the volumes of water that it will need to store to achieve its objectives. It should update the data and information as needed.

6-Month Agency Response

DWR will implement a periodic review process of the information it relies on for Oroville reservoir operations planning. DWR is on track to implement Recommendation No. 5 by May 2024.

California State Auditor's Assessment of 6-Month Status: Pending

60-Day Agency Response

A key input of the SWP planning studies is the DWR's Bulletin 120 hydrology forecast that provides a range of potential water runoff volumes for the given water year. As DWR improves the Bulletin 120, it will automatically be incorporated into the SWP planning studies. DWR will continue to evaluate data needs for the SWP planning studies and update our data accordingly.

California State Auditor's Assessment of 60-Day Status: Pending

As we describe in the text of the report, DWR used various data and information beyond the water supply forecasts in the Bulletin 120 when developing its allocation analysis to inform its Lake Oroville reservoir releases and storage. We found that the data and information DWR used in those analysis was largely historical and possibly outdated. We look forward to reviewing DWR's future updates regarding its evaluation of those data and the need to update it.

Recommendation #6 To: Water Resources, Department of

To ensure that it continually improves the effectiveness of its management of the State Water Project, DWR should develop and implement a formal, written process for reviewing its planning and operations at least once annually. This process should include the following:

1. An assessment of DWR's success at achieving each of the project's various objectives.

2. An evaluation of DWR's actions to achieve its objectives, including the decisions that it made in its planning and in its day-to-day management of the project. DWR should identify actions that assisted it in achieving its objectives and that would benefit its operations in the future, as well as actions that were less effective.

3. Documentation of lessons learned from the evaluation of its actions and, if necessary, updates to its planning or procedural documents to incorporate changes.

6-Month Agency Response

On October 18, 2023, DWR provided the California Water Commission an annual review of the SWP Operations and Planning for Water Year (WY) 2023 and the approach to the SWP Planning and Operations for WY 2024. SWP's presentation to the California Water Commission is available through this webcast link: https://www.water-ca.com/archives.html. On December 4, 2023, and annually thereafter, DWR will provide an in-depth briefing of the past year's planning and operations to the Public Water Agencies at the full-day Water Management Workshop. DWR will develop a policy for conducting periodic reviews of SWP's planning and operations by May 2024.

California State Auditor's Assessment of 6-Month Status: Pending

60-Day Agency Response

DWR continues to provide an annual review of SWP operations that is incorporated into the California Water Commission's annual report (https://cwc.ca.gov/-/media/CWC-Website/Files/Documents/2023/2022_SWPAnnualReview_Final.pdf). DWR is scheduled to provide its next review to the California Water Commission on November 15, 2023, when DWR will provide additional information on its operations.

California State Auditor's Assessment of 60-Day Status: Pending

When we followed up with DWR about its response, staff indicated that DWR intends to implement the recommendation by submitting additional materials for the California Water Commission's next annual report, and that DWR is in the process of determining what additional materials it will provide. When DWR has done so, we will assess whether its actions address all elements of our recommendation.

All Recommendations in 2022-106

Agency responses received are posted verbatim.