California’s largest river, the Sacramento, provides about
30 percent of the state’s surface water runoff.
Once called “the Nile of the West,” the Sacramento River drains
the inland slopes of the Klamath Mountains, the Cascade Range,
the Coast Ranges and the western slopes of the northern Sierra Nevada. The river stretches
some 384 miles from its headwaters near Mount Shasta to the
Sacramento-San
Joaquin Delta.
The Sacramento-San Joaquin Delta is
the largest freshwater tidal estuary of its kind on the west
coast of the Americas, providing important habitat for birds on
the Pacific Flyway and
for salmon and other fish that live in or pass through the Delta.
It’s also the hub of California’s two largest surface water
delivery projects, the federal Central Valley Project
and the State Water
Project. The Delta provides a portion of the drinking
water for some 30 million Californians and irrigation water
for large portions of the state’s $61 billion agricultural
industry.
For nearly half a century, the Delta has been embroiled in
continuing controversy over the struggle to restore the faltering
ecosystem while maintaining its role as the hub of the state’s
water supply. That challenge continues to this day and will be
made more difficult by the growing impacts of climate
change.
The Sacramento-San
Joaquin Delta, part of the largest freshwater tidal estuary
on the West Coast, supports more than 55 fish species and more
than 750 plant and wildlife species. The Delta’s most iconic
native fish is salmon, which rely on a healthy ecosystem for food
and refuge during their migration from the streams where they
were born through the estuary to the ocean, and then back again
to spawn. But the Delta ecosystem has been put under increasing
stress by a combination of factors, imperiling not just
populations of salmon, but several other species as well.
Dozens of agencies have interests
or jurisdiction in the Sacramento-San
Joaquin Delta, ranging from federal and state water supply
and wildlife agencies to local governments and water agencies
that rely on the Delta for their supplies. While that makes for a
messy and constantly changing regulatory tangle, two state
agencies, the State Water Resources Control Board and, to a
somewhat lesser extent, the Delta Stewardship Council, act as the
primary water management referees. State and federal courts have,
at times, weighed in as well.
For roughly a century, between the
mid-1800s and the 1950s, the primary infrastructure in the Delta
consisted of levees built to enable farming in the Delta itself.
But with construction of the Central Valley Project
(CVP) and the State
Water Project (SWP), the Delta became a critical link in
the state’s complex water distribution system. Today, the
majority of people, farms and businesses in California depend on
water transported through the Sacramento-San
Joaquin Delta.
The Sacramento-San Joaquin Delta always has been at the mercy of
river flows and brackish tides.
Before human intervention, salty ocean water from the San
Francisco Bay flooded the vast Delta marshes during dry summers
when mountain runoff ebbed. Then, during winter, heavy runoff
from the mountains repelled sea water intrusion.
The fresh water inflow and outflow of the Sacramento-San Joaquin
Delta is critical to its vitality and survival.
Freshwater flows from the Delta meets saltwater from the ocean
near Suisun Marsh located to the east of San Francisco Bay.
Suisun Marsh and adjoining
bays are the brackish transition between fresh and salt water.
But the location of that transition is not fixed.
The federal Safe Drinking Water Act sets standards for drinking
water quality in the United States.
Launched in 1974 and administered by the U.S. Environmental
Protection Agency, the Safe Drinking Water Act oversees states,
communities, and water suppliers who implement the drinking water
standards at the local level.
The act’s regulations apply to every public water system in the
United States but do not include private wells serving less than
25 people.
According to the EPA, there are more than 160,000 public water
systems in the United States.
Excess salinity poses a growing
threat to food production, drinking water quality and public
health. Salts increase the cost of urban drinking water and
wastewater treatment, which are paid for by residents and
businesses. Increasing salinity is likely the largest long-term
chronic water quality impairment to surface and groundwater in California’s Central
Valley.
As part of the historic Colorado
River Delta, the Salton Sea regularly filled and dried for
thousands of years due to its elevation of 237 feet below
sea level.
The most recent version of the Salton Sea was formed in 1905 when
the Colorado River broke
through a series of dikes and flooded the seabed for two years,
creating California’s largest inland body of water. The
Salton Sea, which is saltier than the Pacific Ocean, includes 130
miles of shoreline and is larger than Lake Tahoe.
Flowing 366 miles from the Sierra
Nevada to Suisun Bay, the San Joaquin River provides irrigation
water to thousands of acres of San Joaquin Valley farms and
drinking water to some of the valley’s cities. It also is the
focal point for one of the nation’s most ambitious river
restoration projects to revive salmon populations.
Located in the middle of California, the San Joaquin Valley is
bracketed on both sides by mountain ranges. Long and flat, the
valley’s hot, dry summers are followed by cool, foggy winters
that make it one of the most productive agricultural regions in
the world.
The valley stretches from across mid-California between coastal
ranges in west and the Sierras on the east. The region includes
large cities such as Fresno and Bakersfield, national parks such
as Yosemite and Kings, millions of people, and fertile farmland.
The San Luis Reservoir is the nation’s largest off-stream
reservoir, serving as a key water facility for both the
State Water
Project (SWP) and the federal Central Valley Project
(CVP).
Southern California’s Santa Ana River is the largest watershed
drainage south of the Sierra and is located largely in a highly
urbanized, highly regulated setting.
At about 100 miles long and with more than 50 tributaries, the
Santa Ana spans parts of San Bernardino, Riverside and Orange
counties as it drains 2,840 square miles of land.
Anne J. Schneider (1947-2010) is
acknowledged as one of the first women to become well-known and
well-respected in the field of California and Western water law.
“Anne was an amazing person — an accomplished college athlete,
mountain climber, skier, marathon runner, velodrome and
long-distance cyclist; a devoted mother; a dedicated
conservationist,” said Justice Ronald B. Robie in the Inaugural
Anne J. Schneider Memorial Lecture in May 2012.
Seawater intrusion can harm groundwater quality in a variety of
places, both coastal and inland, throughout California.
Along the coast, seawater intrusion into aquifers is connected to overdrafting of
groundwater. Additionally, in the interior, groundwater
pumping can draw up salty water from ancient seawater isolated in
subsurface sediments.
