South of Kern River Groundwater Sustainability Plan (GSP) for Certain Lands Overlying the Kern County Subbasin

South of the Kern River Groundwater Sustainability Agencies (SoKR GSAs) | July 27th, 2022

Southeast California Regional Basin Study

U.S. Bureau of Reclamation (USBR) | September 1st, 2015

The United States Department of the Interior’s WaterSMART (Sustain and Manage America’s Resources for Tomorrow) Basin Study Program is a 21st Century approach to help

The United States Department of the Interior’s WaterSMART (Sustain and Manage America’s Resources for Tomorrow) Basin Study Program is a 21st Century approach to help address water supply challenges. The Southeast California Regional Basin Study (Study) takes a collaborative approach to solve local water supply and regional conveyance and storage issues. As part of this Study, the Bureau of Reclamation’s Southern California Area Office cooperated with the Borrego Water District (BWD), Coachella Valley Water District (CVWD), Imperial Irrigation District (IID) and other interested regional stakeholders to assess water supply and demand challenges in the Southeast California region. This Study’s report is comprised of seven chapters; they are: introduction, supply, demand, alternative strategies, alternative analysis, findings, and references. Three appendices provide additional details regarding climate change modeling results, engineering design and economic analysis. The Study focuses on a regional area encompassing the Coachella, Borrego and Imperial Valleys. The Study addresses current and future supply and demand imbalances, provides an assessment of existing infrastructure resources, and develops options and alternatives to solve identified issues and help plan for an uncertain water supply future. The local stakeholders provided substantial informational resources on historical and projected supply and demand, and existing infrastructure. The water districts’ background information includes numerous groundwater, urban water and integrated regional planning studies, all of which were produced and/or updated between 2010 and 2012. Extensive supply and demand studies for the Colorado River Basin and California’s Central Valley – the two imported water supply sources for the Study area – also contributed data to this Study. Reclamation’s Colorado River Basin Water Supply and Demand Study (Colorado River Basin Study) (Reclamation, 2012) and the California Department of Water Resources biennial State Water Project (SWP) report (State of California, 2012 a and b) were both completed in 2012. Reclamation’s Colorado River Basin Study included several technical analyses related to optimal water utilization, conveyance and storage alternatives relative to climate change and future water supply uncertainty. Because the Southeast California Basin Study region is dependent on both Colorado River and SWP imports, several sections of the Study reference and/or summarize both reports extensively. Existing data was used to develop structural and non-structural options to resolve supply-demand imbalances and future uncertainty. Non-structural options included governance, and regulatory or operational changes that could facilitate stakeholder processes to better conserve water or improve the use of existing facilities to convey and store water. Non-structural options were addressed qualitatively due to the complexity of interagency negotiations that would likely be involved. The structural options involved an appraisal level design effort to evaluate pipeline alignments to convey water supplies between the Study stakeholders. Both the structural and non-structural options were assessed in their capability to resolve regional water supply and demand relative to future climate uncertainties. Climate change scenarios analyzed the potential impacts increasing temperatures and changes in precipitation may have on supply and demand across the Study area. The analysis addressed both local and imported supply sources. Climate change is expected to result in increasing temperatures across the Study area and in the Colorado River and SWP basins over time. As temperatures continue to increase, annual precipitation will become more variable. Precipitation changes may affect recharge of the Study area’s local groundwater aquifers and the Colorado River and SWP snowpacks. The climate effects on imported supply have been extensively discussed in the Colorado River Basin Study and the biennial SWP report. Increasing temperatures will increase both supply and demand uncertainty. CVWD could see an increase in SWP supply deliveries under average or greater precipitation-snowpack conditions. Dry years or extended droughts could substantially decrease SWP deliveries. However, CVWD and IID receive the majority of their supply from the Colorado River. Future climate scenarios indicate an increased potential for lower basin shortages. As senior water right holders and under the Secretary of the Interior’s Colorado River Interim Guidelines for Lower Basin Shortages and Coordinated Operations for Lake Powell and Lake Mead, IID and CVWD would not be impacted by short-term shortage issues. The Colorado River Basin Study analysis indicates these shortage vulnerabilities could be mitigated by up to 50% through a variety of management actions and operational changes. Each Study option was assessed as an adaptive strategy to climate change. The structural options to convey and store water in the Borrego Valley groundwater basin are not viable at the present time. A non-structural option may be more cost-effective for the Study region, have the potential to meet the Study objectives, and may offset climate change uncertainty that is impacting available imported water supplies. Further study effort could include fostering groundwater sustainability in the Borrego Valley and promoting opportunities for additional groundwater banking between IID and CVWD in the Coachella Valley, per an October 2003 agreement. Other water and related resource options generated from discussions during the course of this Study include increasing storage opportunities at Lake Henshaw Dam, implementing best practices for flood control basins, and brackish desalination. These options may all play a greater role in diversifying the region’s water supply in the future. However, additional study is required to assess these water resource options.

Southern California winter precipitation variability reflected in 100-year ocean salinity record

Nature Portfolio (Springer Nature) | April 27th, 2023

Rainfall in southern California is highly variable, with some fluctuations explainable by climate patterns. Resulting runoff and heightened streamflow from rain events in

Rainfall in southern California is highly variable, with some fluctuations explainable by climate patterns. Resulting runoff and heightened streamflow from rain events introduces freshwater plumes into the coastal ocean. Here we use a 105-year daily sea surface salinity record collected at Scripps Pier in La Jolla, California to show that El Niño Southern Oscillation and Pacific Decadal Oscillation both have signatures in coastal sea surface salinity. Averaging the freshest quantile of sea surface salinity over each year’s winter season provides a useful metric for connecting the coastal ocean to interannual winter rainfall variability, through the influence of freshwater plumes originating, at closest, 7.5 km north of Scripps Pier. This salinity metric has a clear relationship with dominant climate phases: negative Pacific Decadal Oscillation and La Niña conditions correspond consistently with lack of salinity anomaly/ dry winters. Fresh salinity anomalies (i.e., wet winters) occur during positive phase Pacific Decadal Oscillation and El Niño winters, although not consistently. This analysis emphasizes the strong influence that precipitation and consequent streamflow has on the coastal ocean, even in a region of overall low freshwater input, and provides an ocean-based metric for assessing decadal rainfall variability.

Southwestern United States drought of the 21st century presages drier conditions into the future

Nature Portfolio (Springer Nature) | September 19th, 2022

Intense drought has occurred in the United States Southwest this century, causing unprecedented stress to water resources. Here we use paleoclimate and instrumental reco

Intense drought has occurred in the United States Southwest this century, causing unprecedented stress to water resources. Here we use paleoclimate and instrumental records to establish that the recent temperature rise is incompatible with random draws from past fluctuations, including the current period of warming. Consistent with and extending previous reconstructions, we find that the ongoing drought is the most intense at the 21-year scale back to 600 CE. Evaluation using standardized regression coefficients shows that recent warming damps the effect of moisture delivery on the Standardized Precipitation-Evaporation Index by approximately one-third. The probability of full recovery of the current moisture deficit is unlikely even by mid-century and about five percent in 10-15 years. Evaluation of future climate simulations indicates increasing regional temperature stress and soil moisture depletion, and coupled with long recovery periods for moisture delivery, very low chance for regional mega-reservoirs to regain full-capacity levels assuming current demand.

Spring 2017 Groundwater Level Data Summary

California Department of Water Resources (DWR) | October 3rd, 2022

This document presents a summary of fall 2017 groundwater level data available in the DWR groundwater level database as of February 21, 2018 and includes a discussion of

This document presents a summary of fall 2017 groundwater level data available in the DWR groundwater level database as of February 21, 2018 and includes a discussion of fall 2017, data coverage and groundwater level trends. Statewide precipitation data come from the U.S. Climate Divisional Database, which has data from January 1895 to the present.

State Water Project Allocations, Historical Table A, Water Years 1996-2022

California Department of Water Resources (DWR) | August 30th, 2022

State Water Project Allocations, Historical Table A, Water Years 1996-2023

California Department of Water Resources (DWR) | December 1st, 2022

State Water Project and Central Valley Project Drought Contingency Plan May 1, 2021 – September 30, 2021

California Department of Water Resources (DWR) | May 28th, 2021

This Drought Contingency Plan (Drought Plan) is prepared by the California Department of Water Resources (DWR) and the U.S. Bureau of Reclamation (Reclamation) in an effo

This Drought Contingency Plan (Drought Plan) is prepared by the California Department of Water Resources (DWR) and the U.S. Bureau of Reclamation (Reclamation) in an effort to provide updated information about areas of potential concern given the current dry hydrology of 2021. DWR and Reclamation operate the State Water Project (SWP) and the Central Valley Project (CVP), respectively, to the 2020 Record of Decision (ROD) as analyzed in the 2019 U.S. Fish and Wildlife Service (USFWS) Biological Opinion and 2019 National Marine Fisheries Service (NMFS) Biological Opinion on the Coordinated Long-Term Operation of the Central Valley Project and the State Water Project (Collectively the 2019 Biological Opinions), and DWR also operates the SWP to the 2020 California Department of Fish and Wildlife (CDFW) Incidental Take Permit (ITP). This updated Drought Plan will be submitted by DWR to CDFW in response to Condition 8.21 of CDFW’s ITP. Concurrently, this plan will be shared with the Water Operations Management Team (WOMT) which includes representatives from DWR, Reclamation, USFWS, NMFS, CDFW, and the State Water Resources Control Board (SWRCB) (collectively referred to as Agencies). This report was first drafted in February and subsequently updated in March, April, and May 2021.

Statement from ADWR Director Tom Buschatzke and CAP General Manager Ted Cooke in response to the U.S. Department of the Interior announcement of actions to protect the Colorado River system and 2023 Operating Conditions for Lake Powell and Lake Mead

Arizona Department of Water Resources (ADWR) | August 16th, 2022

Statement of Camille Calimlim Touton, Commissioner, Bureau of Reclamation U.S. Department of the Interior Before the Senate Committee on Energy and Natural Resources June 14, 2022

Senate Committee on Energy and Natural Resources | June 14th, 2022

"The Colorado River Basin is in the 23rd year of a historic drought. Both Lake Powell and Lake Mead – the two largest reservoirs in the United States – are at histori

"The Colorado River Basin is in the 23rd year of a historic drought. Both Lake Powell and Lake Mead – the two largest reservoirs in the United States – are at historically low levels with a combined storage capacity of 28 percent of capacity. While Reclamation and its partners have been successful in conserving water in Lake Mead and Colorado River System reservoirs, more needs to be done as the system reaches critically low water levels. The system is at a tipping point. An example of how Tribal Nations and water managers have addressed these conditions is shown in how, over the past 15 years, approximately 4.6 million acre-feet (maf) have been conserved in Lake Mead through voluntary measures by the three Lower Basin States, Tribal Nations, and Mexico. This has been accomplished through the creation of Intentionally Created Surplus, system conservation water, water for Mexico’s water reserve under Minutes 318, 319, and 323, as well as other water conservation efforts. At current water levels, these measures add 70 feet to Lake Mead’s elevation and delayed the first shortage declaration by six years. Over the past few years, Reclamation has worked with the Upper and Lower Basin States, Tribes, and stakeholders on Colorado River Drought Contingency Plans (DCPs), which were implemented in 2019. The DCPs provide a framework for additional actions to help the basin adapt to drought. An example of this is a 2021 Lower Basin Memorandum of Understanding, called the 500 Plus Plan. The plan, developed under both the DCP and 2021 MOU, aims to conserve additional water above what is required under a Lower Basin shortage condition and contributions under the Lower Basin DCP. The 500 Plus Plan parties have identified and are funding projects in each of the three Lower Basin States, and the projects include tribal, agricultural, and municipal water users. On May 3, 2022, Reclamation announced two separate drought response actions that will help increase Lake Powell storage by nearly 1.0 maf over the next 12 months (May 2022 through April 2023). The two actions include: 1. Approximately 500,000 acre-feet of water will be released from Flaming Gorge Reservoir, located approximately 455 river miles upstream of Lake Powell, pursuant to an agreement as part of the Upper Basin Drought Contingency Plan (adopted in 2019); and 2. Another 480,000 acre-feet will be left in Lake Powell by reducing Glen Canyon Dam’s annual release volume from 7.48 maf to 7.00 maf, as outlined in the 2007 Interim Guidelines that control operations of Glen Canyon Dam and Hoover Dam. Regarding current conditions, in March 2022 Lake Powell dropped below elevation 3,525 feet, meaning the reservoir was less than 35 feet above the minimum power pool of 3,490 feet (i.e., minimum elevation at which hydropower can be generated). According to the May 2022 Most Probable 24-Month Study, the April-July runoff forecast into Lake Powell is 3.80 maf, or 59 percent of average. Lake Powell’s water surface elevation is projected to end the calendar year at 3,522.94 feet (22 percent full). Lake Mead is projected to reach an elevation of 1,039.92 feet (27 percent full) on December 31, 2022. While not official until the August 2022 24-Month Study, a shortage condition for the Lower Basin is projected in calendar year 2023. Looking to the future, Reclamation is preparing to develop new operating guidelines given that the 2007 Interim Guidelines expire in 2026. Reclamation is targeting initiating a formal National Environmental Policy Act (NEPA) process in early 2023. Technical information and lessons learned from management under the current guidelines will be very helpful as the basin strives to develop new guidelines that are durable and drought resilient. Additionally, collaboration and involvement by partners and stakeholders (Tribal Nations, States, water districts, etc.) will be paramount for the effort to be successful. Prior to the start of the formal NEPA process, Reclamation is preparing to issue a “pre-scoping” Federal Register notice (targeting the week of June 20) to ask for input on both the stakeholder engagement process and the substantive elements and strategies for post-2026 operations. Despite the actions taken by the Department and Reclamation, significant and additional conservation actions are required to protect the Colorado River system infrastructure and the long-term stability of the system."