A spatial inquiry case study
Water development in the San Joaquin Valley
Life brings about questions
It takes just one drive on Interstate 5 through California’s San Joaquin Valley to know something is wrong:
Shouting at you in bold red type and all caps, billboard statements like those above interrupt the monotony and undoubtedly shock at least a few of the motorists driving the I-5.
For those unfamiliar with the area, the billboards raise at least a few questions:
Questions inspire research
When faced with a conundrum like this, your trusty map and GIS librarians will likely have a one-word piece of advice for you: maps.
As citizens of the digital age, we are all very familiar with maps. We pull out our phones, search for the nearest library (at least we’d like to think so), and follow the little arrow to our destination. Getting from point A to point B. For most of us, it’s the primary use of maps. Except, perhaps, for those of us who have a map person trying to explain GIS at holiday dinners.
A quick trip to Wikipedia gives us a broader basis on which to think about what a map is. Their definition:
"A symbolic depiction emphasizing relationships between elements of some space, such as objects, regions, or themes"
Research reveals relationships
The question we are left with is: What are the relationships among all these elements?
Historical and contemporary maps can be used to discover, explore, and visualize events by providing foundational context for questions and problems. Based on a snapshot of billboards currently cluttering one of California’s primary highways, what can we say we understand about this event? Dr. Carl Sagan would likely say…not much.
Okay, Dr. Sagan, point taken. Let’s rewind a couple hundred years.
Before the dams
Historically, the San Joaquin Valley was a diverse landscape shaped by nature, with fertile soils and abundant water sources that supported thriving ecosystems and Indigenous communities. So, what changed?
Let’s begin with a brief valley history to understand the present situation.
Setting the scene
In 1868, explorer John Muir rambled his way through the San Joaquin Valley, home to two large river systems, the San Joaquin Basin and Tulare Basin.
Muir was entirely overcome by the valley’s lushness, penning letters to friends with little more than one thing on his mind — flowers.
"The valley of the San Joaquin is the floweriest piece of world I ever walked, one vast level, even flower-bed, a sheet of flowers, a smooth sea ruffled a little by the tree fringing of the river and here and there of smaller cross streams from the mountains."
Indigenous peoples
And that’s how it was before the San Joaquin Valley became one of the world’s breadbaskets — a region widely known for its significant agricultural production.
The Yokuts and Miwok peoples originally inhabited the valley, predating settlers and colonization by thousands of years.
Indigenous communities lived harmoniously with the land, practicing sustainable hunting, gathering, and fishing techniques.
Spanish colonization
The colonization of the San Joaquin Valley began with Spanish explorers and missionaries in the 18th century.
Missions were established to convert Indigenous populations to Christianity and force them into Spanish colonial society.
The Spanish also introduced European farming techniques and livestock, transforming the landscape into large ranchos and haciendas.
Westward expansion
From 1848 to 1855, the California gold rush brought a new wave of settlers to the region in search of opportunity and fortune.
Gold Country, as it was known, extended into Indigenous territories, resulting in Indigenous peoples being violently removed from their ancestral lands.
The influx in population was another blow to the valley's natural resources. Wild game numbers decreased, and food-gathering locales diminished.
Hydrological development
Talks of a large water transport project in the valley began shortly after the completion of the first transcontinental railroad in 1869, which made California more accessible than ever.
Beginning in the late 19th century and booming throughout the 20th, many hydrological projects were initiated to meet the growing demands of industry and population growth.
Today, there are over 1,200 dams and 4,000 miles of canals in California.
Dawn of the dams
It is estimated that about 300,000 Indigenous people lived in California before Spanish colonization. By the end of the 19th century, their numbers were overwhelmed by settlers and immigrants — nearly 2 million people now called California home.
Gone were the days of living harmoniously with the land. Unaccustomed to California’s climate, the newcomers practiced slipshod irrigation techniques, leading to flooding and water scarcity.
And the San Joaquin Valley was at the center of these growing problems. Despite its abundant water resources and fertile soils, the new era of agriculture and urbanization required a system to regulate river flows and water distribution.
This 1951 map from the David Rumsey collection tells the story of the taming of the San Joaquin Valley:
Let’s examine a few components of one of these systems to get an idea of what it brought to — and took from — the valley.
Central Valley Project
Beginning in the late 19th century, multiple negotiations failed to achieve the federal government’s approval and support — until the Great Depression in the 1930s.
In 1937, the U.S. Bureau of Reclamation took over management of the Central Valley Project (CVP) to fulfill the economic need for more farmland via a proposed network of dams, reservoirs, and canals regulating the rivers and the water they supplied.
Shasta Dam
The Shasta Dam was the keystone of the CVP, its primary function being to store water for irrigation in the Sacramento and San Joaquin Valleys.
Completed in 1945, the Shasta Dam was the second-largest dam in the world at the time, and remains the eighth highest dam in the United States. .
Benefits: Irrigation, hydroelectric power, flood management, and saltwater intrusion prevention
Costs: Loss of salmon runs and inundation of hundreds of acres of Indigenous land
Friant Dam and canals
The Friant Dam, completed in 1942, was designed to capture the upper San Joaquin River’s flow and divert its waters into two canals.
The Friant-Kern Canal diverts water south toward Bakersfield, while the Madera Canal diverts water north to the Chowchilla River. Together, the Friant Dam and its canal system provide irrigation water to nearly 900,000 acres in the San Joaquin Valley.
Benefits: Irrigation, hydroelectric power, flood management, and municipal water supply
Costs: 40 miles of dry river and loss of salmon runs
Delta-Mendota Canal
Completed in 1951, the Delta-Mendota Canal stretches 117 miles south from the Jones (Tracy) Pumping Plant to the Mendota Pool, a hydrological feature created by a dam built in 1919.
The canal moves water from the Sacramento-San Joaquin Delta to the west side of the San Joaquin Valley, where it is used for irrigation.
Benefits: Irrigation, hydroelectric power, flood management, municipal water supply, and recreation
Costs: Migratory fish (many species) disruption and saltwater intrusion
After the dams
Agricultural impact
The CVP system is just a portion of the hydrological development that grew to dominate California’s landscape. Water management for irrigation remained the focus into the 1970s, with little attention being paid to ecological repercussions.
Let's take a look at the agricultural result of hydrological development in California.
This map shows locations of dams and canals throughout the state, along with the agricultural footprint found in California.
Water management in California By the numbers
Description | Volume |
|---|---|
⏺ Dams and reservoirs | 1,200 |
– Canals | 4,000 miles |
Water used for irrigation | 16.1 million acre-feet |
Irrigated cropland | 4.5 million acres |
Agriculture-related jobs | 340,000 people |
Agriculture-related revenue | $24 billion |
Environmental impact
By the 1980s, it became painfully apparent that hydrological development had essentially destroyed the natural abundance of the San Joaquin Valley. The San Joaquin River lost 95% of its wetlands. Nearly 60 miles of the river no longer flowed. And Chinook salmon runs ceased to exist in the main stem of the river.
Groups like the San Joaquin River Committee and River Parkway Trust formed to begin identifying sustainable solutions to balance caring for the valley’s ecosystem with the booming agricultural demands.
Let's take a look at some of the protected lands in the San Joaquin Valley.
San Joaquin River Ecological Reserve
The San Joaquin River Ecological Reserve comprises 958 acres along a southern portion of the river. It includes a riparian corridor and series of ponds that support a range of wildlife from herons to beavers to several species of fish.
San Joaquin River National Wildlife Refuge
The San Joaquin River National Wildlife Refuge covers 7,500 acres and is situated where three major rivers —Toulumne, Stanislaus, and San Joaquin — converge. The refuge prioritizes migratory birds, endangered species, and riparian and wetland habitat restoration.
San Luis National Wildlife Refuge
The San Luis National Wildlife Refuge comprises over 26,000 acres in the northern San Joaquin Valley — with the San Joaquin River running along its eastern portion. It includes wetlands, riparian woodlands, native grasslands, and vernal pools that support migratory birds and elk.
Learn more
With much work completed in the late 1980s to bring attention to the ecological devastation in the San Joaquin Valley, the Central Valley Project Improvement Plan (CVPIA) was authorized in 1992. The plan mandated changes in water policies to prioritize protection, restoration, and enhancement of fish and wildlife for the first time since the inception of the CVP in the 1930s.
While much work has been done in the last 30 years to reverse the damage caused by hydrological development in the valley, there is still much to be done. Learn more from these organizations about future restoration plans and how you can support them.
