Experts report that without further adaptation to prepare for worsening climate change impacts, California will see significant losses of available water and potentially devastating effects on watersheds.
From Natalie Hanson, Courthouse News Service
California officials say that the state must better prepare for the impending impacts of climate change to avoid potentially devastating losses of water in coming years.
The state’s Department of Water Resources on Wednesday released the 2023 State Water Project Delivery Capability Report, analyzing current and future expectations for California’s water supply. Experts reported that the state’s delivery capability and reliability could decrease by as much as 23% within 20 years due to changing flow patterns and extreme weather shifts. That’s equivalent to about 496,000 acre-feet per year, enough to supply more than 1.7 million homes for one year.
“The analysis released today underscores the need to modernize and upgrade our aging infrastructure so we can capture water supplies when it’s wet. Modernizing the State Water Project is critical to delivering on the human right to water in California,” Karla Nemeth, Department of Water Resources director, said in a statement Wednesday.
Experts project that California’s population, now just over 39 million, may boom to 43 million people by 2030. They say it’s therefore imperative to prepare for water shortages as the Golden State will see increasingly extreme weather conditions. Periods of high flows that current infrastructure cannot properly capture will clash with long, severe dry periods, according to the report.
The State Water Project’s service area comprises the world’s eighth-largest economy, with more than eight million people living in disadvantaged communities. The report introduces two new approaches to analyze current climate change conditions, and officials recommend emphasizing projects to upgrade infrastructure and better prepare for climate change such as a new reservoir and desalination projects.
Under one of three presented climate change scenarios, the experts reported that if agencies continue to manage water in the same way as conditions become increasingly hot and dry, then the estimated average annual water delivery would measure 13% to 22% lower than under existing conditions.
“Users of this scenario should assume that current climate model simulations indicate that actual 2043 climate conditions would have about a 25% chance of being worse than the conditions represented in this scenario,” the experts wrote. “Put another way, there is an approximately 25% chance that planning (for) only this scenario would leave an agency under planned and potentially under-prepared for the actual climate conditions to which they need to operate.”
The state emphasized the Sacramento-San Joaquin Delta and efforts to protect its fragile ecosystem while managing water exported from the converging rivers for agricultural and urban uses. The west San Joaquin Valley alone depends on the delta for about 75% of its irrigation supply to produce billions of dollars worth of food each year.
“The delta’s importance to California’s economy and natural heritage cannot be overstated,” the experts wrote. “California would not be the same without that water — hundreds of billions of dollars of economic activity depend upon it.”
Officials report that the Department of Water Resources, the U.S. Bureau of Reclamation, the Water Board and resource agencies are collaborating on new operating permits for the Central Valley Project and a water quality control plan update. In addition, delta water users will explore new ways to cut water use and improvement local habitats.
“Despite uncertainties in future regulations and climate conditions, the 2023 DCR unmistakably demonstrates substantial reductions in delivery capability and reliability if no or insufficient action is taken,” Nemeth wrote. “Immediate action is imperative to address the impact of a warming climate, with the report indicating that these effects are already in motion.”
Built in 1960, the state water project spans more than 700 miles and consists of canals, dams, reservoirs, pumping plants and power plants which provide water to 27 million Californians and 750,000 acres of farmland.
“The state water project was designed for the climate of the 20th century when our precipitation fell as snow more reliably between October and May and we could capture that water effectively for future use,” the project’s deputy director John Yarbrough said in a statement. “We need to continue to adapt and invest in the SWP, so that we can add flexibility and resilience for 21st century conditions and we can avoid these losses in reliability.”
California became the first state to adopt urban water use efficiency targets with the enactment of the Water Conservation Act of 2009. In 2018, two new water conservation laws, Assembly Bill 1668 and Senate Bill 606, created a new conservation framework to establish new urban water use objectives. Building on the framework, Governor Gavin Newsom in April released an updated California Water Plan outlining 142 state actions like building new infrastructure to store and move water.
Other coverage …
State Water Project supplies could fall up to 23% within 20 years due to climate change
“Climate change threatens to dramatically shrink the amount of water California can deliver over the next 20 years and could reduce supplies available from the State Water Project by up to 23%, according to new projections released Wednesday by Gov. Gavin Newsom’s administration. The analysis by the California Department of Water Resources examined a range of climate change scenarios and projected that by 2043 the average amount of water transported through the massive network of reservoirs and canals to more than half the state’s population could decline between 13% and 23%. Such a loss in the State Water Project’s water delivery capacity, if not addressed, could lead to major shortages for much of the state, including Southern California. “The SWP was designed for the climate of the 20th century,” said John Yarbrough, the project’s deputy director. “It’s going to need continued investment to get it in a place where it’s really able to function with the hydrology of the future.” … ” Read more from the LA Times.
SEE ALSO:
- New report estimates potential water losses due to climate crisis, actions to boost supplies, press release from DWR
- California reservoir levels could drop much more than expected in the future, state report finds, from the San Francisco Chronicle
Reactions …
From Jennifer Pierre, General Manager of the State Water Contractors
“DWR’s final Delivery Capability Report underscores what California’s water managers have known and have been planning for: ongoing shifts in hydrology in California will require newfound investments to ensure we can move and store water when it’s wet for use when it’s dry, for generations to come. The volume of water provided by the SWP cannot easily or affordably be replaced so it is imperative that as part of a suite of actions to shore up water supply portfolios throughout the state, we modernize and upgrade the state’s main water delivery infrastructure and implement science-based regulations.
The report shows that SWP deliveries could drop by between 13%-23% in the next 20 years if no reinvestments in the SWP are made. A 23% drop in supply is a worst-case scenario, built for planning purposes on the assumption that we will do nothing to modernize, adapt, and upgrade our water infrastructure and regulatory structure. That’s good for planning, but thankfully not the case. Water managers are, in fact, proactively analyzing and developing adaptation strategies—including the Delta Conveyance Project, Agreements to Support Healthy Rivers and Landscapes (Agreements), Forecast Informed Reservoir Operations (FIRO), and improved above- and below-ground storage opportunities—to ensure the projected supply reductions never become a reality for California.
While the outlined climate adaptation strategies are critical, needed and long overdue, we need to make sure we can afford their associated costs. Currently, contractors who rely on State Water Project supplies shoulder all the costs, including for public benefits such as flood control, electric grid reliability and significant costs to support important recreation facilities and opportunities throughout the state. Just as the State Water Contractors are prepared to ensure reinvestment in the State Water Project, so too should the state and federal government ensure that all of the benefits continue to accrue to all Californians. The State Water Project’s service area would rank as the eighth largest economy in the world if it were its own nation, and the final DCR shows without question that we must invest in California’s water infrastructure for the millions of people and important farmland that relies on it for California’s continued prosperity.”
From Californians for Water Security:
“The effects of climate change are already upon us. We cannot sit back and do nothing while our water supplies steadily decrease. It is long past time to advance the Delta Conveyance Project to prepare for a more uncertain water future. Time is running out.”
The report finds that our current infrastructure is ill-prepared for the challenges of climate change, including “weather whiplash” of prolonged droughts followed by intense rainy seasons, higher temperatures, and shifting hydrology. The system’s losses can be mitigated by investments in storage and conveyance infrastructure like Sites Reservoir and the Delta Conveyance Project.
