In Brief

California’s record-level drought followed by massive rain and floods has drawn attention to the state’s neglected water management and infrastructure challenge. However, the state’s obsolete, inefficient water infrastructure system threatens effective statewide water delivery even during non-drought conditions. California must elect a more aware team to manage these issues that have been severely neglected while other unnecessary expenditures have been worked on such as the high speed rail.  

California Must Prepare for Flood and Drought NOW! However, I want to see first hand the issues instead of just reading and relying all the reports. Politicians too often rely on written reports that could be manipulated for grant money or government supported programs. I want tours and explanations of our water resource facilities and dams.


California is experiencing record wet conditions following five consecutive years of drought.
  • In 2015, we had record low statewide mountain snowpack of only 5 percent of average.
  • The 4 driest consecutive years of statewide precipitation in the historical record were in 2012-14.
  • Water year 2017 (October 1, 2016-September 30, 2017) is now surpassing the wettest year of record (1982-83) in the Sacramento River and San Joaquin River watersheds and close to becoming the wettest year in the Tulare Basin (set in 1968-69).
  • Mountain snowpack is already well above the April 1 seasonal averages throughout the Sierra Nevada, with the southern Sierra being more than 200 percent of average for the year to date.

California experiences the most extreme variability in yearly precipitation in the nation. The summary on California Precipitation by the Center for Western Weather and Water Extremes at the Scripps Institution explains how large storms (often atmospheric river storms) contribute to those extreme changes. Water year 2017 has been an active year for atmospheric river storms.

The potential for wide swings in precipitation from one year to the next shows why we must be prepared for either flood or drought in any year. Although this year may be wet, dry conditions could return again next year. 2017 may be only a wet outlier in an otherwise dry extended period. Unfortunately, the scientific ability to determine if next year will be wet or dry (known as sub-seasonal to seasonal forecasting, or long-range weather forecasting) isn’t yet capable of delivering reliable predictions.

NASA Report: San Joaquin Valley Land Continues to Sink

West Washington Road where it crosses the Eastside Bypass, a constructed floodway for the San Joaquin River

Aqueduct before and after subsidence

Estimated subsidence in the San Joaquin Valley between 1949-2005

February 8, 2017

New NASA radar satellite maps prepared for the California Department of Water Resources (DWR) in the report, Subsidence in California, March 2015-September 2016, show that land continues to sink at in certain areas of the San Joaquin Valley, putting state and federal aqueducts and flood control structures at risk of damage.

“The rates of San Joaquin Valley subsidence documented since 2014 by NASA are troubling and unsustainable,” said DWR Director William Croyle. “Subsidence has long plagued certain regions of California. But the current rates jeopardize infrastructure serving millions of people. Groundwater pumping now puts at risk the very system that brings water to the San Joaquin Valley. The situation is untenable.”

A prior August 2015 NASA report prepared for DWR documented record rates of subsidence in the San Joaquin Valley, particularly near Chowchilla and Corcoran, as farmers pumped groundwater in the midst of historic drought.  The report released today shows that two main subsidence bowls covering hundreds of square miles grew wider and deeper between spring 2015 and fall 2016.  Subsidence also intensified at a third area, near Tranquillity in Fresno County, where the land surface has settled up to 20 inches in an area that extends seven miles.

Additional aircraft-based NASA radar mapping was focused on the California Aqueduct, the main artery of the State Water Project, which supplies 25 million Californians and nearly 1 million acres of farmland.  The report shows that subsidence caused by groundwater pumping near Avenal in Kings County has caused the Aqueduct to drop more than two feet.  As a result of the sinking, the Aqueduct at this stretch can carry a flow of only 6,650 cubic feet per second (cfs) – 20 percent less than its design capacity of 8,350 cfs.  To avoid overtopping the concrete banks of the Aqueduct in those sections that have sunk due to subsidence, water project operators must reduce flows.

The California Department of Water Resources (DWR), which operates the State Water Project, is analyzing whether the subsidence-created dip in the Aqueduct will affect deliveries to Kern County and Southern California water districts.  If the State Water Project allocation is 85 percent or greater, delivery may be impaired this year due to the cumulative impacts of subsidence in the Avenal-Kettleman City area.

2013 marked the driest year on record for many regions in the state, and the same conditions are likely to persist in 2014. The state’s major reservoirs – Lake Shasta, Lake Oroville, and San Luis reservoir – were at 36%, 36%, and 47% capacity, respectively, at the end of January 2014 (Figure 1a). While many attribute the state’s unpredictable water supply to the drought and rising temperatures, California’s current drought conditions actually reveal weakness in the state’s water supply management policies.

Figure 1a. Water Conditions for Major ReservoirsFigure 1a. Water Conditions for Major Reservoirs

Even under normal conditions, without the necessary policy reforms and different funding sources, California’s water supply would still be unreliable. The state’s old and insufficient water infrastructure, largely unmanaged groundwater supplies, inefficient water use, and environmental issues are just some of the threats to the state’s future water supply in the short- and long-term. As the population continues to grow and temperatures continue to rise, these challenges will intensify.

Figure 1b. California Daily Water Use (in gal, per capita)Figure 1b. California Daily Water Use (in gal, per capita)

California’s water availability varies within the state, particularly between the northern and southern regions. More than 75% of the state’s precipitation occurs in Northern California, but Southern California demands 75% of the state’s water. Furthermore, while water usage per capita has declined over time, California’s growing population is likely to drive greater water demand overall in the future (Figure 1b).

Water Supply & California’s Economy

In much of California, access to water has been unreliable in the face of numerous demands for various uses. Based on water consumed only by municipal, industrial, and agricultural users, agriculture uses approximately 80% of the total “developed water supply.” Although agriculture remains an important source of income for the state, California’s economy has become less reliant on water-intensive industries. For example, agriculture and other water-related industries now account for only 2% of the state’s Gross Domestic Product.

California receives the greatest portion of agricultural revenue in the U.S. (11.3%). In some cases, crops that generate large portions of the state’s agricultural revenue require less acreage and less water compared to cheaper crops. During drought conditions, the state could increase its water use efficiency as well as its agricultural revenue by focusing production on valuable crops that require less water and acreage.

California Surface Water Storage

California has done little to expand its surface water storage facilities in recent decades. The backbone of the state’s water system, the federal Central Valley Project (CVP) and State Water Project (SWP), have made no significant infrastructure investments since the 1970s. These projects designed their reservoirs to satisfy the water demands of the state’s population when it was only about 19 million, half the size of the current population. California’s fast-growing population is likely to increase water demand. Thus the aging water infrastructure is insufficient to satisfy the demands of California’s 38 million current residents.

There have been significant developments in local surface storage construction such as the Diamond Valley Reservoir, which serves the Metropolitan Water District of Southern California in Riverside County. However, the federal government owns most of California’s major reservoirs that require maintenance. Additionally, considering warmer temperatures, there is likely to be more winter precipitation falling as rain instead of snow. Therefore, California’s water supply system should have a sufficient number of efficiently operating reservoirs to satisfy the needs of the growing population and maintain sufficient reservoir space for winter flood control.

Building (about $2.3 to 3.2 billion) and maintaining (about $10 to $21 million annually) reservoirs and dams is costly, but it provides the state with operational flexibility. For example, they provide drought protection by compensating for the snowpack loss due to higher temperatures, environmental protection by releasing water when needed, and manage floodwaters. Thus while maintaining and building new surface water infrastructure is costly in the short-term, it secures the state’s essential water supply system and offers the opportunity to respond to emergencies.

Unregulated Groundwater

California’s surface and underground water is all part of the same system, yet, surface water is generally considered a public good, while ground water is considered a private good. As such, two different legal systems regulate surface and groundwater in California. This decentralized management could lead to an irreparable “groundwater overdraft,” which occurs when water is released faster than it is replaced through absorption. Groundwater overdraft can especially happen during drought conditions because there is insufficient surface water available. They can cause land to sink, or in case of coastal aquifers, lead to seawater intrusion. Some areas of the San Joaquin Valley have already started sinking at an alarming rate.

Groundwater storage is widespread, but these underground storages refill and empty much slower than the surface reservoirs, which makes them a more suitable water source during droughts. Between 1998 and 2005, groundwater resources supplied about 35% of California’s average annual water demand in urban, agricultural, and managed wetland areas. During drier years, this portion increased to 40% or higher statewide and as more than 60% in some regions.

The state has previously implemented various strategies to address groundwater management challenges and make it a more reliable water supply source. However, California still lacks a formal state-administered system that regulates and permits groundwater use.

Environmental Measures Affecting Water Supply

The Sacramento-San Joaquin River Delta (“The Delta”) is the hub of California’s two main water delivery systems – the SWP and the federal CVP. It is an important ecosystem and also a critical link in California’s water supply system. Therefore, it has been the center of a power struggle among urban water use, agricultural water use, and environmental objectives.

As a result of recent drought conditions, a state court has ordered restrictions on Delta water pumping to protect certain fish species from extinction because water pulled directly through Delta channels increases the risk of fish getting trapped in the pumps. Additionally, the existing operations of the SWP and CVP pumps can reverse river flows, which can potentially alter salmon migratory patterns and contribute to the decline of sensitive fish species such as the Delta smelt. The court-ordered restrictions further reduces the surface water supply. Consequently, water users may turn to local underground resources, which can lead to a groundwater overdraft.

To resolve the dispute and increase water supplies, water agencies proposed the Bay Delta Conservation Plan. This plan includes the construction of two tunnels that would carry water beneath the Delta to the SWP and CVP pumping plants, and from there, the water would travel into the existing water channels that currently supply much of the state’s water. However, this solution requires strict governance and financial policies, as well as a systematic science program and ecosystem restoration under new conditions. This proposal, if successful, could solve the Delta’s environmental problem while stabilizing the water supply.

Water Efficiency and Conservation

As Professor Barton Thompson, Co-Director of Stanford University’s Woods Institute for the Environment, said, we “cannot run out of water…all we can do is run out of cheap water.” Water is a scarce resource in California, and policymakers have primarily focused on increasing the supply of water to meet increased demand. Policymakers should also consider incentivizing reduced demand for water, particularly when it is extremely scarce.

“In theory, cities cannot run out of water. All we can do is run out of cheap water, or not have as much water as we need when we really want it.”
– Barton Thompson, Co-Director of Stanford University’s Woods Institute for the Environment

Public institutions regulate most of California’s water so that it is priced far below true market value in urban and agricultural areas. Further, water prices do not adjust automatically to periods of shortage and excess.

However, research studies have shown that even higher water prices affect the public’s demand for water very little in California. Thus increasing the cost of water may be ineffective in reducing municipal water use. Yet, studies have found that increasing water prices may reduce agricultural water demand. Given the state’s dependence on the agricultural sector for food and resources, raising water prices could have additional negative effects, such as a significant increase in food prices.

Funding Challenges

California’s local agencies are more responsible for delivering water services and maintaining infrastructure than the state and federal governments. They mainly fund their operations through monthly water and wastewater bills. State and federal spending is low relative to the local agencies’ water expenditures. In the late 2000s, local agencies spent about $30.3 billion annually, while state and federal agencies spent about $3.1 billion and $510 million, respectively (Figure 1c).

Figure 1c. California’s Annual Water Expenditures in late 2000s (% of Total Expenditure)Figure 1c. California’s Annual Water Expenditures in late 2000s (% of Total Expenditure)

General obligation bonds, funded by tax revenues, have become a more reliable source of funding for the local agencies’ water projects. But water expenses have exhausted the existing water bond funds, and due to concerns regarding weak voter support, the state Legislature has postponed a ballot measure for the new bond until November 2014.

Due to recent drought conditions, Governor Brown announced a $687.4 million emergency drought-relief plan, which includes funds for housing and food for workers directly impacted by the drought, as well as secures emergency drinking water supplies. Critics such as the Minority Assembly leader Connie Conway and Vice Chair of the Assembly Water, Parks and Wildlife Committee Frank Bigelow have called the Governor’s plan an ineffective “drop in the bucket.” The Governor further proposed an additional $142 million in the May Revised budget to continue the immediate drought-related efforts. The state must develop a range of funding options to successfully face the challenges of sustainable water supply management.


In recent years, water agencies have made significant progress towards creating a reliable water supply system. However, California’s water system still faces a number of challenges such as old and insufficient water infrastructure, largely unmanaged groundwater supplies, inefficient water use, and environmental issues. These challenges have become even more difficult to tackle with population growth and higher temperatures. Thus improving water supply management policies and finding sustainable funding sources are essential means for the state to develop an effective and reliable water supply system.