Oroville Dam is the centerpiece and largest water storage
facility of the State Water Project. Located about 70 miles north
of Sacramento at the Feather River confluence, Oroville Dam
creates a reservoir that can hold 3.5 million acre-feet of water.
Features such as a fish barrier dam and pool at Oroville Dam made
the SWP one of the first major water projects built with
environmental protections as a major consideration.
Besides storing water, the dam also protects downstream residents
from the floodprone Feather River—the main feeder of the SWP— and
provides major water recreation facilities such as boating,
fishing and camping.
Citing the near disaster at Oroville Dam, a group of
congressional Democrats is pushing the government’s watchdog
agency to investigate federal oversight of dam safety
regulations. … Separately, the California state Senate
Natural Resources and Water Committee will hold an oversight
hearing on Oroville next Tuesday [April 25].
A disaster expert’s review of the Oroville Dam spillway
emergency says the Department of Water Resources could have
prevented everything with better design, better construction
and better maintenance. Robert Bea prepared the report
A coalition of environmental groups that had warned Oroville
Dam’s emergency spillway was fatally flawed long before it
nearly washed away this winter is demanding that federal
regulators open up dam repair plans for public vetting.
Late in the afternoon of Feb. 12, Sheriff Kory Honea was at the
emergency operations center for the tallest dam in America when
he overheard someone say something that stopped him in his
tracks: “This is not good.”
The company that built one of greater Sacramento’s most
important flood-control projects in years will fix the damaged
spillways at Oroville Dam, site of a near catastrophe two
months ago. … Kiewit has considerable experience with dam
projects, including the decadelong, $900 million upgrade of
As state officials clamp down on records at Oroville Dam, one
of the country’s foremost experts on catastrophic engineering
failures has used state inspection reports, photographs and
historical design specifications to piece together an autopsy
detailing why the spillway at the country’s tallest dam failed
so spectacularly this winter.
California water officials Monday awarded a $275 million
contract to repair the troubled Oroville Dam to a subsidiary of
one of the world’s largest construction companies that is
headquartered in Omaha, Nebraska.
Design flaws, construction shortcomings and maintenance errors
caused the Oroville Dam spillway to break apart in February,
according to an independent analysis by Robert Bea for the
Center for Catastrophic Risk Analysis at UC Berkeley.
State officials have reopened the damaged spillway at Oroville
Dam as another set of rainstorms began moving across Northern
California. … Water will continue pouring down the spillway
for up to two weeks, depending on how much more rain falls.
Blowing past state officials’ financial projections, three
construction contractors submitted bids for the Oroville Dam
repairs that begin at $275 million, the Department of Water
Resources said Saturday. … DWR said it would spend the
weekend reviewing the bids and declare a winner Monday.
California’s top water official said Thursday he’s considering
releasing redacted copies of safety and progress reports at the
troubled Oroville Dam after his office had tried to keep them
secret because of terrorism concerns.
With stormy weather approaching, state water managers announced
Thursday they will resume releasing water down a damaged
spillway at the nation’s tallest dam. The badly eroded main
spillway at California’s Oroville Dam hasn’t been used since
It’s not just the residents of Oroville, Gridley and Yuba City
who are frustrated with the Department of Water Resources’ lack
of transparency concerning the Oroville Dam spillways. Two
California legislators who represent those living downstream
from the dam are also upset that they aren’t getting answers.
… The state Senate’s Natural Resources Committee has a
hearing scheduled at 9 a.m. April 25 that will go over what
happened with the Oroville Dam spillway.
Gov. Jerry Brown’s administration is using federal security
regulations written to thwart terrorism to deny public access
to records that experts say could guide repairs to the Oroville
Dam and provide insight into what led to the near catastrophic
failure of its emergency spillway.
California’s Dept. of Water Resources has announced a
fast-track plan to replace the shattered spillways at Oroville
Dam — at least partially — by November 1, when the rainy season
is expected to resume. Meanwhile, engineers at Oroville Dam are
drilling cores and conducting geological studies, hoping to
better understand February’s near-catastrophic spillway
California officials on Thursday announced an ambitious plan to
increase the size of Lake Oroville’s damaged main spillway,
allowing it to release nearly twice as much water, as they seek
to rebuild the 3,000-foot-long concrete chute that gave way
State officials sketched a two-year recovery plan Thursday for
the battered Oroville Dam spillway, revealing a blueprint
that’s far from complete, still in need of a price tag and
certain to leave the structure partially damaged as the next
rainy season approaches.
The Department of Water Resources can operate the Oroville Dam
project in an emergency capacity until Aug. 24. The U.S. Army
Corps of Engineers approved an emergency permit for the state
water agency Feb. 24, and it is good for six months.
Since the Oroville Dam spillway incident highlighted flaws in
the current system, Yuba-Sutter officials are in the process of
revising evacuation plans. Both Yuba and Sutter counties have
been gathering information from the public regarding the
February evacuation and plan on using the situation as a
Citing potential security risks, state and federal officials
are blocking the public’s ability to review documents that
could shed light on repair plans and safety issues at crippled
Oroville Dam. … The secrecy on the part of state dam
operators prompted state Sen. Jim Nielsen to call for an
immediate oversight hearing.
President Donald Trump announced Sunday more than a
half-billion dollars would be coming to California to help
cover the damage from the winter storms, including $274 million
for repairs to the Oroville Dam spillway. The fulfillment of
the fourth presidential declaration for damage from the winter
storms totals an estimated $540 million.
The state Department of Water Resources gave the overseeing
federal agency of the Oroville Dam what it asked for last week
— a schedule for the independent review team investigating the
cause of the spillway failures, but it listed no deadline for a
final report from the team.
The operators of Oroville Dam acknowledged Monday they might
not be able to permanently repair the dam’s battered main
spillway in time for the next rainy season, but said they’re
confident the fractured structure will be usable.
California’s top water manager said Monday that the
problem-plagued Oroville Reservoir will have a new spillway in
place to prevent potentially dangerous outflows of water in
time for the next rainy season.
In the wake of a near disaster at Oroville Dam caused by heavy
runoff and a damaged spillway, the former chief of flood
operations for the U.S. Army Corps of Engineers said last week
it may be time to reconsider how the reservoir is operated to
avert such dilemmas.
The main spillway at Oroville Dam is riddled with design flaws
and so badly damaged that an independent panel of experts hired
by the state has concluded it’s probably impossible to repair
the structure completely before the next rainy season begins in
Safety experts say there is no time for delay in a state plan
to restore the 770-foot Oroville Dam, and they warn California
would face a “very significant risk” if a damaged spillway is
not in working order by fall, the start of the next rainy
In their 70s and 80s now, some men who built the Oroville Dam
still remember those tough days well, some 50-odd years later.
Most of the people they worked with have since passed on, but
some of the former construction workers who are living in
Oroville have continued to meet up over the years.
In the nearly 50 years since the Oroville Dam was completed,
construction methods have changed. Chico State University
construction management professor Chris Souder consulted on the
Folsom Dam auxiliary spillway project which began construction
in 2008 and is on pace to be completed in October.
The state Department of Water Resources Friday said the cost
associated with the ongoing crisis at Oroville Dam totaled
about $100 million through the end of February. … Meanwhile,
dam operators Friday began releasing water down the damaged
main spillway for the first time since flows were halted there
Naturally-occurring asbestos has been found in the rock
formations and in the air near the damaged Oroville Dam main
spillway, according to a press release. Although California
Department of Water Resources said risk to workers and the
surrounding community is minimal, dust-control operations are
The Department of Water Resources is planning to resume flows
this week through Oroville Dam’s damaged main spillway, and
warns that Feather River flows will increase to 40,000-50,000
cubic feet per second.
Long before a fractured spillway plunged Oroville Dam into the
gravest crisis in its 48-year history, officials at a handful
of downstream government agencies devised a plan they believed
would make the dam safer: Store less water there.
A damaged flood control spillway at the Oroville Dam may have
to be used as early as next week as storm runoff and snowmelt
continue to fill the massive reservoir on the Feather River,
state water officials said.
Just how many people are out working at Oroville Dam in
response to the spillway emergency and how much is it going to
cost? Both reporters and elected representatives have struggled
to get an answer to that question.
When state water officials scaled back their mass dumping of
water from the damaged Oroville Dam this week, they knew the
riverbed below would dry up enough to allow the removal of vast
piles of debris from the fractured main spillway.
There are 1.7 million cubic yards of rubble at the bottom of
the Diversion Pool, effectively splitting it into two bodies of
water. The plan with the spillway shut off, according to the
California Department of Water Resources, is to remove enough
of it to clear a channel and get the water that is backed up on
one side of the rubble to flow between the two sides.
California Natural Resources Secretary John Laird told the U.S.
Senate Environment and Public Works Committee on Wednesday that
further deterioration of the nation’s aging flood control and
water infrastructure systems will put lives at risk.
Crews worked Tuesday to clean up dirt and debris from the base
of Oroville Dam and biologists rush to save stranded fish after
state officials shut off the flow of water from a damaged
spillway at the Northern California lake.
Geologists attempted for the first time Tuesday to figure out
what to do about the vast, yawning canyon dug out of the earth
after a crater opened up in the Oroville Dam’s concrete
spillway and diverted water at high speed into the adjacent
When California state biologists crested a sandbar along the
Feather River on Tuesday morning, they expected to find at
least some of the water that just a day before had raged
through the channel, too deep to stand in – and plenty of fish
needing to be rescued.
[Oroville] Dam operators gradually scaled back water releases
to zero over a six-hour period, providing breathing room for
construction crews trying to clear debris from a badly choked
Feather River channel and restart the dam’s critically needed
For three weeks, Oroville Dam’s fractured main spillway and the
surrounding hillsides have taken a nearly nonstop pounding. The
stunning waterfall crashing down what’s left of the 3,000-foot
concrete span has split the spillway in two and carved massive
canyons on either side.
Oroville Dam operators plan to halt water releases from the
dam’s battered spillway Monday in order to ramp up efforts to
remove a debris pile that’s preventing them from restarting a
As heavy winter storms continue to hammer California, the
Legislature is launching a review of dam and levee safety and
bracing for major investments necessary to shore up flood
control throughout the state.
Nine days ago, with the Oroville Dam under stress and battered
by more harsh weather, Gov. Jerry Brown said he had no
immediate plans to visit the site, suggesting “I don’t think
they need politicians fluttering around.”
Lake Oroville will partially reopen on Thursday, nearly two
weeks after more than 180,000 Northern California residents
evacuated their homes and the lake area closed due to fears
that the emergency spillway at Oroville Dam could fail.
The Department of Water Resources plans to remove at least some
of the debris at the bottom of the Oroville Dam spillway and
study the structure, but just aren’t sure when they’ll have a
chance to do that.
Not far from the main drag through Oroville, a dozen local
business owners and city officials faced each other in a hotel
lunchroom Tuesday. They sought to begin developing an
advertising campaign to transform a barrage of negative images
and news reports about frantic efforts to prevent catastrophic
flooding into a lucrative tourist attraction, albeit after the
Feather River Basin’s rainy season ends in April.
After the state Department of Water Resources reached its goal
early Monday morning of lowering the water level at Lake
Oroville by 50 feet, officials said heavy rains would likely
cause lake levels to rise several feet.
Twelve years ago, widespread destruction from Hurricane Katrina
on the Gulf Coast helped compel federal engineers 2,000 miles
away in California to remake a 1950s-era dam by constructing a
massive steel-and-concrete gutter that would manage surging
waters in times of torrential storms.
The badly damaged main concrete spillway at Oroville Dam
was pounded by massive volumes of stormwater this month,
but its failures occurred well short of the maximum flow that
engineers designed the system to handle.
Communities just downstream of California’s Lake Oroville dam
would not receive adequate warning or time for evacuations if
the 770-foot-tall dam itself – rather than its spillways – were
to abruptly fail, the state water agency that operates the
nation’s tallest dam repeatedly advised federal regulators a
Dam experts around the country are focusing on a leading
suspect: Tiny bubbles. The prospect is simple, yet terrifying
and has been the culprit in a number of near disasters at dams
across the globe since engineers discovered about 50 years ago.
Water releases through the damaged main spillway at Oroville
Dam were scaled back Thursday to allow crews to reach and
remove a pile of debris that has built up at the bottom of that
chute, officials said.
Feeling confident they’ve created sufficient empty space in
Lake Oroville for the time being, state Department of Water
Resources officials said they reduced spillway outflows so they
could address another looming challenge: restarting the dam’s
hydroelectric plant, which can release additional water when
Jeffrey Mount, a leading expert on California water policy,
remembers the last time a crisis at the Oroville Dam seemed
likely to prompt reform. It was 1997 and the lake
risked overflowing, while levees further downstream failed
and several people died.
Rainwater erosion alongside the Oroville Dam’s main spillway
appears to have contributed to the heavy damage that prompted a
crisis, forcing more than 100,000 to be evacuated from their
homes, a report reviewed by The Times showed.
Days before nearly 200,000 people downstream of Lake Oroville
were ordered to evacuate because of problems with two spillways
at the dam, there were millions of other evacuees – residents
of the Feather River Fish Hatchery. … Why all the
trouble for some fish? Spring-run Chinook salmon and steelhead
are both listed as threatened under the Endangered Species Act.
Officials raced to drain more water from a lake behind battered
Oroville Dam as new storms began rolling into Northern
California on Wednesday and tested the quick repairs made to
damaged spillways that raised flood fears.
The critical document that determines how much space should be
left in Lake Oroville for flood control during the rainy season
hasn’t been updated since 1970, and it uses climatological data
and runoff projections so old they don’t account for two of the
biggest floods ever to strike the region. … Most
recently, the issue of outdated dam manuals came up in the
context of California’s five-year drought.
When operators of Oroville Dam suddenly ordered evacuations on
Sunday, it focused a big spotlight on a crucial piece of
California’s flood-control infrastructure – spillways.
… Some of these dams are getting upgrades, albeit
Work crews repairing Oroville Dam’s damaged emergency spillway
are dumping 1,200 tons of rock each hour and using shotcrete to
stabilize the hillside slope, an official with the Department of
Water Resources told the California Water Commission today.
The pace of work is “round the clock,” said Kasey Schimke,
assistant director of DWR’s legislative affairs office.
At churches, fairgrounds and other makeshift shelters,
thousands of Californians packed what belongings they had into
garbage bags and suitcases to return home Tuesday, two days
after they were told to flee the threat of massive flooding
from a dam’s damaged spillway.
Six months before rushing water ripped a huge hole in a channel
that drains a Northern California reservoir, state inspectors
said the concrete spillway was sound. As officials puzzle
through how to repair Oroville Dam spillway, federal regulators
have ordered the state to figure out what went wrong.
With both spillways badly damaged and a new storm approaching,
America’s tallest dam on Tuesday became the site of a desperate
operation to fortify the massive structures before they face
another major test. … In a sign of the progress made
Tuesday, officials downgraded the evacuation order to a
warning, allowing all evacuated residents to return home.
President Trump issued major disaster declarations to enable
federal funding for California on two fronts — to aid with the
Oroville Dam spillway damage and mass evacuations and to help
the state deal with the widespread effects of January’s storms.
There’s another storm bearing down on troubled Oroville Dam,
set to begin late Wednesday. But state officials say they
believe the precipitation will be mild enough – and the
reservoir empty enough – to handle this latest challenge.
Shock over the emergency evacuation downriver from the Oroville
Dam has given way to serious questions about how California is
coping with its aging infrastructure — which the American
Society of Civil Engineers says would cost the state a
staggering $65 billion per year to fix and maintain after years
A huge Northern California reservoir, held in place by a
massive dam, has always been central to the life of the towns
around it. Now the lake that has brought them holiday fireworks
and salmon festivals could bring disaster.
Gov. Jerry Brown asked the Trump administration for a federal
disaster declaration for the emergency at Oroville Dam on
Monday evening, citing the impending arrival of more storms and
the potential need to resort again to the dam’s emergency
spillway, which has been severely eroded.
As California waited Monday night to see if President Donald
Trump would grant Gov. Jerry Brown’s request for emergency
funding for 10,000 evacuees who lived in the shadow of the
Oroville Dam, FEMA began preparing for the worse.
California Gov. Jerry Brown, appealing to the Trump
administration for direct federal assistance on the Oroville
Dam’s emergency spillway, said Monday that he remains
encouraged that the state and federal government can work
Water levels dropped Monday at California’s Lake Oroville,
stopping water from spilling over a massive dam’s potentially
hazardous emergency spillway after authorities ordered the
evacuation of nearly 200,000 people from towns lying below the
lake. California Department of Water Resources officials are
waiting for the light of dawn to inspect an erosion scar on the
spillway at the Oroville Dam, the nation’s largest.
More than a decade ago, federal and state officials and
some of California’s largest water agencies
rejected concerns that the massive earthen spillway at
Oroville Dam — at risk of collapse Sunday night and prompting
the evacuation of 185,000 people — could erode during heavy
winter rains and cause a catastrophe.
A gaping hole in the spillway for the tallest dam in the United
States has grown and California authorities said they expect it
will continue eroding as water washes over it but the Oroville
Dam and the public are safe.
As storm runoff poured into fast rising Lake Oroville Thursday,
the state resumed releases down the reservoir’s damaged
spillway, creating dramatic scenes of muddy torrents gushing
over the concrete chute.
With stormwater and snowmelt pouring into the reservoir faster
than expected, the operator of the crippled Oroville Dam said
it was likely water would have to be released from the
facility’s emergency spillway as soon as Saturday – a
last-ditch alternative that officials had been hoping to avoid.
State engineers gingerly began releasing water again through
the damaged Oroville Dam spillway Wednesday in a controlled
test to see how much water the scarred facility could handle,
as reservoir levels continued to climb behind the critical
California’s recovery from drought has been so remarkably quick
that reservoirs on the verge of record lows just a year ago are
now too full to handle more rain, prompting dam operators
across the state to unleash surpluses of water not seen in
After a few nice days, stormy weather is due to return
Wednesday night and stick around into next week. In preparation
for that, the Department of Water Resources kicked up releases
from Oroville Dam by a third Tuesday afternoon, to make room
for runoff in Lake Oroville.
After years of drought, Northern California has so much water
that the state’s two largest reservoirs are releasing water to
maintain flood-control safety. … Shasta and Oroville are
the twin anchors of California’s giant water-delivery
With Lake Oroville rising more than 82 feet this month, the
water level is now cutting into the buffer needed for flood
control. … Other north state reservoirs have increased
their outflows as they encroach on flood control limits.
Explore the Sacramento River and its
tributaries through a scenic landscape as we learn about the
issues associated with a key source for the state’s water supply.
All together, the river and its tributaries supply 35 percent of
California’s water and feed into two major projects: The State
Water Project and the federal Central Valley Project.
This 3-day, 2-night tour travels across the Sacramento Valley and
follows the river north from Sacramento through Chico to Redding
and Lake Shasta, where participants take a houseboat ride.
The last hurdle in relicensing the Oroville Dam facilities may
be only a few more months away, according to the National
Marine Fisheries Service. The agency has been working on a
biological opinion to determine how the dam and facilities
downstream could impact endangered and threatened fish and
What’s holding up the relicensing of Oroville Dam facilities?
Fish. Specifically, an opinion on how three threatened species
might be affected, according to local Department of Water
State officials are estimating that Bidwell Canyon’s three
available concrete lanes will close this week when the lake
level drops 220 feet below the top of Oroville Dam. The dam is
considered full at 900 feet above sea level.
Authorities have recovered thousands of stolen archaeological
artifacts reportedly taken from Lake Oroville over the last 20
years. …State regulations, as well as other federal laws,
protect items of cultural significance from being removed from
The Water Education Foundation’s popular Northern California
Tour features a diverse group of experts talking about
groundwater, flood management, the drought, water supplies,
agricultural challenges, and the latest on salmon restoration
efforts. The tour also includes a houseboat cruise on Lake
Shasta. … The tour travels the length of the Sacramento
Valley with visits to Oroville and Shasta dams.
This 25-minute documentary-style DVD, developed in partnership
with the California Department of Water Resources, provides an
excellent overview of climate change and how it is already
affecting California. The DVD also explains what scientists
anticipate in the future related to sea level rise and
precipitation/runoff changes and explores the efforts that are
underway to plan and adapt to climate.
Water as a renewable resource is depicted in this 18×24 inch
poster. Water is renewed again and again by the natural
hydrologic cycle where water evaporates, transpires from plants,
rises to form clouds, and returns to the earth as precipitation.
Excellent for elementary school classroom use.
The 24-page Layperson’s Guide to California Water provides an
excellent overview of the history of water development and use in
California. It includes sections on flood management; the state,
federal and Colorado River delivery systems; Delta issues; water
rights; environmental issues; water quality; and options for
stretching the water supply such as water marketing and
A new look for our most popular product! And it’s the perfect
gift for the water wonk in your life.
Our 24×36 inch California Water Map is widely known for being the
definitive poster that shows the integral role water plays in the
state. On this updated version, it is easier to see California’s
natural waterways and man-made reservoirs and aqueducts
– including federally, state and locally funded
projects – the wild and scenic rivers system, and
natural lakes. The map features beautiful photos of
California’s natural environment, rivers, water projects,
wildlife, and urban and agricultural uses and the
text focuses on key issues: water supply, water use, water
projects, the Delta, wild and scenic rivers and the Colorado
Oroville Dam is the centerpiece of
the State Water
Project (SWP) and its largest water storage facility.
Located about 70 miles north of Sacramento at the confluence of
the three forks of the Feather River, Oroville Dam is an
earthfill dam (consisting of an impervious core surrounded by
sands, gravels and rockfill materials) that creates a
reservoir that can hold 3.5 million acre-feet of water.
This printed copy of Western Water examines California’s drought
– its impact on water users in the urban and agricultural sector
and the steps being taken to prepare for another dry year should