Colorado River

Droughts in California

Public Policy Institute of California (PPIC) | April 1st, 2021

Economic Analysis of the 2014 Drought for California Agriculture

University of California, Davis (UC Davis) | July 15th, 2014

California is enduring its third driest year on record as agricultural, urban and environmental demands for water are at an all-time high. This report presents an assessm

California is enduring its third driest year on record as agricultural, urban and environmental demands for water are at an all-time high. This report presents an assessment of the economic impacts of the 2014 drought on crop production, livestock and dairies using a suite of models.  This analysis extends the preliminary estimates of the Central Valley drought impacts released May 19, 2014 (Howitt et al. 2014) to include:  •Broadened coverage of the Statewide Agricultural Production Model (SWAP) to include majoragricultural areas on California's central and south coasts and inland farms of the Imperial,Coachella and Palo Verde valleys, •Updated SWAP agricultural production and economic impact estimates for the Central Valleyusing the most current data available, •Estimated Central Valley impacts if the drought persists through 2015 and 2016, includingeconomic effects and the impact of increasing groundwater depletion and pumping depths usingthe California Department of Water Resources’ (DWR) C2VSIM model, •Estimated fallowing of cropland due to drought using the SWAP model, •Estimated losses to dairies and livestock using a supply elasticity approach based on pasturelosses and feed crop prices, and •Comments on the preliminary draft from various state agencies. The study finds that the 2014 drought will result in a 6.6 million acre-foot reduction in surface water available to agriculture. This loss of surface water will be partially replaced by increasing groundwater pumping by 5 million acre-feet.  The resulting net water shortage of 1.6 million acre-feet will cause losses of $810 million in crop revenue and $203 million in dairy and other livestock value, plus additional groundwater pumping costs of $454 million. These direct costs to agriculture total $1.5 billion. The total statewide economic cost of the 2014 drought is $2.2 billion, with a total loss of 17,100 seasonal and part-time jobs. Table ES-1 summarizes the key findings of the study. 

Economic Analysis of the 2015 Drought for California Agriculture

University of California, Davis (UC Davis) | August 17th, 2015

In 2015 California agriculture is facing its fourth year of severe drought. As in 2014, irrigation districts and farmers are showing more resilience to the drough

In 2015 California agriculture is facing its fourth year of severe drought. As in 2014, irrigation districts and farmers are showing more resilience to the drought than many had anticipated. Groundwater substitution has again greatly reduced crop fallowing and job losses. Water trading and operational flexibility also have significantly reduced the costs of the drought, and preservation of the most valuable crops has helped buffer economic impacts. However, the effects of drought are unevenly distributed over regions. In some regions with limited groundwater reserves the economic and employment impacts are very severe. In others, there is an increased cost of expanded groundwater use which is partially offset by high crop prices. Just as the economic impacts of the drought have grown modestly since 2014, continuation of the drought to 2016 or beyond with similar intensity is likely to slowlyerode the state’s agricultural production and employment.

Economic Impacts of the 2020–22 Drought on California Agriculture

University of California, Merced (UC Merced) | November 22nd, 2022

California just ended its third consecutive year of drought, resulting in the driest three-year period in the instrumental record. Multi-year deficits in precipitation in

California just ended its third consecutive year of drought, resulting in the driest three-year period in the instrumental record. Multi-year deficits in precipitation in the state’s usually wetter northern regions have been compounded by increased crop evaporative demands, leading to water scarcity impacts to agriculture across the state. Although 2020 was a dry year, water reserves stored during the wetter years of 2017 and 2019 greatly diminished drought impacts during that year. The water outlook changed rapidly in 2021—the third driest water year on record with the highest evaporative demand. The northern regions of the state—including the Sacramento Valley, the Scott and Shasta valleys, the Pit River valleys (northern intermountain valleys), and the Russian River—faced unusually dry conditions. Drought emergency conditions in 2021 were proclaimed first in the Russian River, Scott River and Shasta River basins, which faced subsequent curtailments. Water curtailments were extended to the Sacramento Valley later in the season. Water for local agriculture, ecosystems, exports, and water quality protection in the Sacramento-San Joaquin Delta were compromised by low water reserves. Atmospheric rivers in October and December 2021 provided temporary drought relief for a portion of the state, but record low precipitation from January-September allowed for extreme drought conditions to reign into the 2022 water year. To overcome persistent precipitation deficits and below-average storage in major reservoirs, the state again implemented water rights curtailments and low water deliveries from the State Water Project. The US Bureau of Reclamation announced reduced Central Valley Project deliveries—including unprecedented cutbacks to senior contractors in the Sacramento Valley—and local agencies implemented cutbacks as a first tier of drought response measures. Compared with the 2021 water year, however, 2022 brought less severe water cutbacks in the San Joaquin Valley. This report provides estimates of the economic impacts to agriculture for first three years of the current drought, which began in 2020. We use a combination of climate, hydrologic, agricultural and economic models, supplemented by informal surveys of irrigation districts and remote sensing data. The study includes nearly 88% of the 8.7 million acres of irrigated crop area in the state (LandIQ, 2019) excluding idle land. Our preliminary analysis for 2020–21 (Medellín-Azuara et al. 2022), focused on the Central Valley, and also examined the Russian River basin (North Coast), and northern intermountain valleys in Siskiyou, Shasta, and Modoc counties. Here, we expanded our spatial coverage to include the Central Coast, South Coast, and Colorado River.

Economics of a State Water Resources Program

Legislative Analyst's Office (LAO) | July 9th, 1957

Effective at Any Scale: Watershed-based Decision Support Tools

San Francisco Estuary Institute (SFEI) | July 1st, 2016

EcoAtlas  tools apply the USEPA’s three-level wetland monitoring and assessment framework for wetland and stream protection in a variety of California watersheds, an

EcoAtlas  tools apply the USEPA’s three-level wetland monitoring and assessment framework for wetland and stream protection in a variety of California watersheds, and it can be adjusted to more generally support natural resource planning, assessment, monitoring, and reporting. EcoAtlas operationalizes the Wetland and Riparian Area Monitoring Plan (WRAMP) by enabling users to assess the abundance, distribution, diversity, and condition of wetlands in the landscape or watershed context.

Effects of imported recharge on fluoride trends in groundwater used for public supply in California

Science of the Total Environment (Elsevier) | March 31st, 2022

Fluoride is a naturally occurring element in groundwater that supports bone and dental health at low concentrations but can cause health problems at elevated concentrati

Fluoride is a naturally occurring element in groundwater that supports bone and dental health at low concentrations but can cause health problems at elevated concentrations in drinking water. This study investigates spatial and temporal trends for fluoride concentrations in untreated groundwater from over 20,000 public supply wells in California. The presence of a significant temporal trend in fluoride concentrations in a well was assessed using the Mann-Kendall test and a spatial-weighting approach was used to identify the areal extent of the groundwater resources with significant trends. Less than 2% of the groundwater resources used for public supply in the state have concentrations above the California maximum contaminant level of 2 mg/L. Approximately 14% of the groundwater resource used for public supply show a significant recent trend (2000–2019), with decreasing trends occurring in 10%of the resource. Potential drivers for trends were evaluated in two of the areas in southern California with the greatest prevalence of trends but distinct climate and hydrogeological characteristics. Aquifers in the Mojave and Whitewater River watersheds, located in the desert region, and the Los Angeles Basin, located on the coast, have been replenished with imported and treated water over the last half century to maintain sustainable groundwater levels. The recharge of imported water with different chemistries has altered the geochemical conditions in the aquifers, driving changes in fluoride concentrations.

Efficient Water Use in California: Water Rights, Water Districts, and Water Transfers

Rand Corporation (Rand) | November 13th, 1978

Elevated Grand Canyon groundwater recharge during the warm Early Holocene

Nature Portfolio (Springer Nature) | October 2nd, 2023

Summer rainfall is an important contributor to water budgets in western North American deserts, where intense rainfall sustains ecosystems while also causing flash floods

Summer rainfall is an important contributor to water budgets in western North American deserts, where intense rainfall sustains ecosystems while also causing flash floods and damaging erosion. A better understanding of Grand Canyon palaeoclimate and the long-term history of the summer monsoon from summer-sensitive palaeoclimate records will improve our ability to project future hydroclimatic changes under warmer conditions. Here we show multi-proxy evidence for an intensification of the Early Holocene (11,700–8,200 years ago) hydrological cycle linked to a stronger and expanded summer North American Monsoon from calcite oxygen and uranium isotopes in a uranium-series precisely dated stalagmite from a Grand Canyon cave. Our results suggest that subsurface infiltration was greater in the Early Holocene than today at Grand Canyon. A data–model comparison with an isotope-enabled climate model suggests that enhanced infiltration was due to an Early Holocene monsoon intensification associated with rising atmospheric temperature. Projections of a future increase in precipitation intensity or more frequent and expanded North American monsoon rain events may paradoxically result in increased subsurface infiltration at Grand Canyon and other high-altitude plateaus, even within the context of western North American aridification in a hotter climate.

Enduring Solutions on the Colorado River

Arizona State University (ASU) | August 16th, 2024

As we work to reduce water use on the post-2026 Colorado River, two paths lie open before us. One is to incentivize conservation by giving water users the chance to bank

As we work to reduce water use on the post-2026 Colorado River, two paths lie open before us. One is to incentivize conservation by giving water users the chance to bank saved water for later use. Known most commonly as Intentionally Created Surplus (ICS), and more broadly in a series of increasingly creative implementations as “Assigned Water,” this creates short term savings. But in the long run, the approach entitles the users to take the water back out of thE bank. The other involves permanent reductions – “System Water.” Water use is reduced for the benefit of the Colorado River as a whole. Investment in Assigned Water, attractive to water managers because of the allure that they can get their water back, has crowded out investment in the more durable System Water reductions that will be needed to bring the Colorado River into balance. As we develop new operating rules for the river, we need to be mindful of the differences involved. Accounting for water as Assigned Water is a means to reduce total water use in the short-term but the basin requires a means to reduce total water use over the long-term. Enduring solutions on the river can only be found by addressing overallocation, which at its most basic means that there needs to be more unassigned water in Lake Mead. Click here for Part II