The Sacramento Valley, the northern part of the Central Valley,
spreads through 10 counties north of the Sacramento–San Joaquin
River Delta (Delta). Sacramento is an important agricultural
region, growing citrus, nuts and rice among many other crops.
Water flows from the Sierra Nevada Mountain Range to the region’s
two major rivers — the Sacramento and American – and west into
the Delta. Other rivers include the Cosumnes, which is the
largest free-flowing river in the Central Valley, the lower
Feather, Bear and Yuba.
The Sacramento Valley attracts more than 2 million ducks and
geese each winter to its seasonal marshes along the Pacific
Flyway. Species include northern pintails, snow geese, tundra
swans, sandhill cranes, mallards, grebes, peregrine falcons,
heron, egrets, and hawks.
Faulty design, construction and repairs of the main Oroville
Dam spillway allowed water to seep under its floor and build
up, lifting a concrete slab Feb. 7 into the water flowing down
the chute, starting a chain of events that largely wrecked the
Sites Reservoir has been talked about for decades, but now that
project officials — and backed by 70 major allies — have
formally submitted an application for state bond money, the
question arises: Will this $5 billion project actually come to
Bad design and construction of the tallest U.S. dam a
half-century ago and inadequate state and federal oversight
since then led to a disastrous spillway collapse in February,
an independent national team of dam safety experts said Tuesday
as they urged tougher safety reviews nationwide.
A team investigating the Oroville Dam spillway breach in
February said it has not seen evidence that a comprehensive
review of its construction and design has ever been conducted
since it was built nearly 40 years ago. … Agencies like
the Bureau of Reclamation, which operates Shasta Dam, do more
comprehensive construction and design reviews.
A team of independent experts charged Tuesday that the state
and federal officials who inspected Oroville Dam relied too
heavily on visual inspections, ignoring blueprints,
construction records and other documented clues that could have
warned them about the dam’s troubled flood-control spillway
long before it fractured in February. … The forensic
team’s report brought a swift response from Assemblyman James
Gallagher, R-Yuba City, whose constituents were among those
The most detailed report yet on what went wrong at Oroville Dam
last winter when 180,000 people fled amid fears of flooding
found that state and federal officials failed to uncover
long-standing construction and maintenance issues at the
nation’s tallest dam.
The UC Berkeley group analyzing the state Department of Water
Resources’ response to the spillway crisis is still not
satisfied with the department’s explanation for Oroville Dam’s
“green spot” in a report released earlier this week.
The state Department of Water Resources has released a report
on the Oroville Dam’s “green spot,” declaring the extensive
area of persistent moisture on the face of the dam is due to
seasonally trapped rainfall and poses no threat to the dam’s
Taxpayers have spent billions of dollars on dams, levees and
bypasses to keep Sacramento and other Central Valley towns and
cities from flooding, but experts say the infrastructure would
prove no match for a megastorm like the one that pummeled
Houston this week.
It’s been six months since a failure of the Oroville Dam
Spillway led to the evacuation nearly 200,000 people, including
hundreds who took refuge at an evacuation center at the Nevada
County Fairgrounds as well as hotels in the Grass Valley and
Nevada City area.
A man has been sentenced to 13 years in state prison after
pleading no contest to charges he broke into an Oroville market
during the Oroville Dam spillway evacuations in February, Butte
County District Attorney Mike Ramsey announced Friday.
The Oroville City Council fired off a critical letter to the
Federal Energy Regulatory Commission, criticizing how the
Department of Water Resources operates Oroville Dam and
demanding a host of changes.
Construction at the Lake Oroville spillways is on schedule to
meet a Nov. 1 deadline for this year’s repairs, according to
the Department of Water Resources. The department has passed
the midway point on its construction timeline for this year’s
repairs on the main spillway, which was badly damaged during
high February releases.
Each year, participants on the Northern California Water Tour
enjoy three days exploring the Sacramento Valley during the
temperate fall. Join us as we travel along the Sacramento and
Feather rivers through a scenic landscape and learn about
issues associated with storing and delivering the state’s water
The [McClellan] Air Force has consistently denied that toxins
have escaped the base boundaries and contaminated drinking
water supplies, but a series of new lawsuits by two area water
districts seeking $1.4 billion in damages has renewed concerns
among some who spent years drinking water from area pipes and
Sacramento County led a cascade of area governments suing the
state in an effort to block the Delta tunnels, saying the $17
billion project would harm local farmers, endangered fish and
low-income communities at the south end of the county.
The state Department of Water Resources is beginning to lay the
gravel foundation for spawning salmon. This comes as much of
the gravel was washed away with high flows from the Oroville
Dam spillway this winter.
The failure of the Oroville spillway in February led people to
notice a large green spot on Lake Oroville’s dam. The spot has
been there for years, but the questions remain as to whether
it’s a sign the dam is leaking.
Federal disaster officials have agreed to chip in $22.8 million
to help California pay the estimated $500 million cost of the
Oroville Dam crisis. … Department of Water Resources
spokeswoman Erin Mellon said Wednesday during a biweekly
conference call with reporters that she expects more money to
come the state’s way.
Consider a couple of scenarios for big trouble at Oroville Dam:
First: The facility’s main concrete spillway suffers serious
damage, resulting in erosion of the rock beneath it — and
potentially threatening the safety of the dam itself.
In a sweeping legal fight that could affect drinking water
supplies for thousands of Sacramento-area residents, two water
districts near the old McClellan Air Force Base are suing the
federal government for $1.4 billion to clean up the
cancer-causing chemical hexavalent chromium from the area’s
Several Oroville city councilors have voiced criticism about
the mayor’s communication with representatives of the state
Department of Water Resources and the State Water Contractors
during the height of the Oroville Dam crisis.
One week before the deadline to formally seek payment from the
state of California for damages stemming from the Oroville
Dam’s spillway failure this year, the state has received 93
claims worth a combined $1.1 billion.
Six months ago, relentless winter storms dumped nearly 13
inches of rain in four days on the Sierra Foothills, tearing an
enormous hole in the spillway at Oroville Dam, the nation’s
highest, and leading to an unprecedented emergency that
prompted the evacuation of 188,000 people from nearby towns.
Today, what could have been ground zero for America’s worst dam
disaster is now a hotbed of construction activity.
The heavy work is now underway on emergency repairs to the
nearly 3 miles of levee protecting the heart of Yuba City. The
Sutter Butte Flood Control Agency received federal approval
Tuesday night to proceed wth the work.
Work crews with heavy machinery started emergency repairs
Thursday to a levee that protects Yuba City, and was damaged by
high flows during the Oroville Dam spillway emergency. The
$28.5 million project will create a seepage cutoff wall and
rebuild 2.9-miles of levee along the west side of the Feather
River that protect 80,000 people.
Lawyers filed a $15 million government claim on Tuesday on
behalf of walnut farmers who say they lost more than two dozen
acres of land along the Feather River when the Oroville Dam
spillway failed in February, causing massive flooding and
destructive erosion in the area below.
Drone video released by the California Department of Water
Resources shows how repairs are moving along at the Oroville
Dam’s main spillway, which crumbled during the extremely wet
winter and forced the evacuation of 180,000 people.
The deadline is Aug. 14 to apply for water storage funding from
the Proposition 1 bond measure voters approved in 2014, and
while the folks working to build Sites Reservoir will be
applying, they don’t need the money. Enough water agencies have
agreed to invest in the reservoir near Maxwell that it can be
built without taxpayer funds, according to Sites Project
Authority General Manager Jim Watson.
Officials in charge of repairing the damaged spillways at Lake
Oroville said they’ve received the needed authorization from
state and federal agencies for 2017 construction plans.
The plan now is to continue preparing the demolished main
spillway for concrete to be poured over the next few weeks.
A new report from a UC Berkeley group researching what caused
the Lake Oroville spillway to fail in February is concerned
that a green spot on the nation’s tallest dam might mean it is
leaking. This is not the first time the “green spot” on the
southern end of Oroville Dam has been brought up.
Northern California farmer John Duarte, facing millions of
dollars in fines for plowing a Sacramento Valley wheat field,
previously sought help from President Donald Trump’s attorney
general and EPA chief to get the government off his back. Now
Duarte is making an 11th-hour bid for a dismissal of the
federal government’s high-profile case against him.
One of the country’s foremost experts on catastrophic
engineering failures released a new report Thursday on the
troubled Oroville Dam that asks a disturbing question: Is the
country’s tallest dam leaking?
State water resources officials and federal regulators caused
the failure of the Oroville Dam spillway in February by
ignoring long-established guidelines and neglecting their duty
to manage risks and detect flaws, a scathing report by a
Berkeley engineering expert concluded Thursday.
Construction work on a portion of the Marysville Ring Levee –
deemed by a federal agency as the “weakest link” in the city’s
levees – began earlier this month along Highway 70. …
John Nicoletti, a levee commissioner for Marysville, said the
U.S. Army Corps of Engineers has assessed the ring levee and
found that Binney Junction is the city’s most vulnerable point.
Many lake users have complained to the state about fewer
recreational opportunities on the lake in the aftermath of the
Lake Oroville spillway disaster in February. Since then, the
lake level has dropped significantly, meaning boaters have
farther to walk after parking their vehicles at the high-water
In its eighth memorandum released Thursday, the independent
board analyzing the redesign of the Oroville Dam spillways
commends the construction contractor’s work and makes slight
tweaks to former recommendations.
The state Department of Water Resources has filed a request
with the Federal Energy Commission to demolish and reconstruct
an additional 240 feet of the main Oroville Dam spillway upper
chute this season. The purpose of the change is to ensure the
reconstruction can be complete in two seasons, per a recent
Congressman Doug LaMalfa doesn’t want a new license issued for
Oroville Dam until some safety questions are answered and some
commitments are made to local government. LaMalfa, R-Richvale,
sent a letter to Federal Energy Regulatory Commission acting
Chairwoman Cheryl LaFleur requesting the delay.
The Department of Water Resources have asked federal regulators
to let it demolish and replace an additional 240 feet of the
spillway’s 3,000-foot concrete chute before the rains comes
this fall, leaving less work for next year.
Nearly 80 days after winning the bid to fix the disastrous
Oroville Dam spillways, the contractor Kiewit offered the Chico
Enterprise-Record and Oroville Mercury-Register Friday a
close-up view of construction efforts.
The preliminaries are just about over. Permanent structural
repairs are about to begin at Oroville Dam. Five months after
an unprecedented emergency forced a mass evacuation, state
officials said Wednesday they’re ready to start replacing the
now-demolished lower portions of Oroville’s main flood-control
Anyone who contemplated the wreckage of the Oroville Dam’s main
spillway back in February — either while water was pounding
down the shattered concrete structure or when the flow was
stopped later and the enormity of the damage was fully visible
— probably had this thought cross their mind: “That is going to
be tough to fix.”
Facing a crisis after a huge crater formed in the main
flood-control spillway at Oroville Dam, officials at the
California Department of Water Resources called in an old hand
to help: David Gutierrez, a nationally known engineer who had
just retired as chief of the agency’s dam-safety division.
Inside a cavernous northern Utah warehouse, hydraulic engineers
send water rushing down a replica of a dam built out of wood,
concrete and steel – trying to pinpoint what repairs will work
best at the tallest dam in the U.S for a spillway torn apart in
February during heavy rains that triggered the evacuation of
200,000 people living downstream.
Work at the Oroville Dam will carry on in spite of the 110
degree-plus temperatures anticipated this week. There are
protections in place for construction employees with the
contractor, Kiewit, and concrete has to undergo a cooling
techniques to be able to keep applying it, said Jeff Petersen,
the company’s project director in a press conference call
A California farmer facing a $2.8 million fine
for allegedly plowing seasonal wetlands on his 450-acre
Tehama County land lashed out Friday against federal
prosecutors and bureaucrats for what he called an abuse of
The rush of workers and heavy machinery to the shore of Lake
Oroville is so vast and unfamiliar it’s fanning rumors across
this rural region that the ruckus couldn’t just be for a
historic dam repair. … But as state officials gave The
Chronicle a tour last week of the construction site, they said
the effort was both extensive and relatively straightforward.
From hundreds of fish annually to nearly 9,000 per year, Butte
Creek salmon are thriving, thanks to a project begun 20 years
ago. That project was celebrated Thursday at Gorrill Ranch on
the Midway. … Bruce Babbitt, Secretary of the Interior for
the Clinton administration, helped bring the players to the
negotiating table to get the Butte Creek Salmon Recovery
Project, completed in the late 1990s.
California farmer John Duarte, facing a hefty fine over
water-law violations for plowing a field, wants to call in a
big gun in his high-profile court case in Sacramento: Scott
Pruitt, the administrator of the U.S. Environmental Protection
In February, damage to the spillway of the dam on Lake Oroville
in Butte County, California, and erosion under the dam’s
emergency spillway threatened to send billions of gallons of
water cascading through dozens of California communities.
The dam did not collapse, but the damage to the spillway and
the emergency spillway was enormous.
Quick thinkers who came up with a plan to rescue millions of
salmon using fresh water from fire hydrants during the Oroville
Dam emergency were recognized for their efforts Sunday by
legislators, the state Department of Fish and Wildlife and
In the latest skirmish over transparency at the troubled
Oroville Dam, a Northern California activist group has sued
state officials alleging they’re illegally withholding
information about potentially toxic asbestos.
State officials released a strategic plan Friday aimed at
reducing risks associated with different stages of migration
for salmon and steelhead throughout the Sacramento Valley river
system. “These resiliency strategies are an exciting new path
for improving conditions for fish and wildlife in the
Sacramento Valley,” said David Guy, president of the Northern
California Water Association.
Pieces of the Feather River Fish Hatchery have been patched
back together in time for the return of spring-run chinook
salmon. However, the shoveling, shifting and trucking will
continue for a while until its smooth swimming for the
important fish-rearing station on Table Mountain Boulevard.
State and federal agencies have big plans to change the way
water flows through Anderson River Park. … The test pits
are being dug to prepare for a project that would create a
place where young salmon can eat, grow and get ready for their
migration out to the Pacific Ocean, officials said.
The helicopters alone cost more than $100,000 a day at one
point. Weeks of dredging debris ran to more than $22 million.
And on the day after the massive evacuation, as the crisis was
peaking, the state spent $3,902 on breakfasts and lunches for
Not just concrete and rebar, but “human and organizational”
factors that could have contributed to the emergency at the
Oroville Dam spillway will be included in the investigation
currently underway by an independent team of experts assembled
by two national dam associations.
If you’re expecting a quick and easy answer on what caused the
spillway failure at Oroville Dam, think again. The leader of
the independent forensics team studying the Oroville crisis
said Thursday that the crack in the dam’s main flood-control
spillway likely was caused by a combination of problems.
The Enterprise-Record/Oroville Mercury-Record got its closest
look so far Wednesday at the Oroville Dam spillway work on a
site visit hosted by the state Department of Water Resources.
… The visit included an hour-long meeting in a conference
room at DWR’s Oroville headquarters, and a trip to catch a view
of lower spillway blasting around 12:30 p.m. followed by access
to the structure above the spillway.
John Duarte spent five years fighting the Obama
administration’s Justice Department over charges that he broke
environmental laws by harming wetlands while planting a wheat
crop on his Northern California farm. He lost his case, and
faces a $2.8 million fine.
When it comes to repairing the tallest dam in America,
sometimes it helps to shrink the problem to a more manageable
size. That’s why California water officials are relying on a
scale model of the damaged spillway at Oroville Dam to plan
State Parks expects a busy Memorial Day weekend at Lake
Oroville even with the spillway dominating the news. … A
portion of Lake Oroville remains closed as construction
continues at the Oroville Dam spillway.
“Four or five Friday nights” of work has paid off for Briana
Conners, who recently won $10,000 for her winning entry in a
contest seeking proposals to get fish past tall dams like
Shasta Dam. … While the U.S. Bureau of Reclamation sponsored
the contest to solicit ideas for getting fish around tall dams,
the agency is specifically interested in finding ways to get
young endangered salmon around Shasta Dam.
The Department of Water Resources invited downstream levee
maintaining agencies and county emergency operators to a
meeting in Oroville on Monday to discuss ways of improving
operations and planning for future emergency situations.
A farmer faces trial in federal court this summer and a $2.8
million fine for failing to get a permit to plow his field
and plant wheat in Tehama County. … Because the property has
numerous swales and wetlands, [John] Duarte hired a consulting
firm to map out areas on the property that were not to be
plowed because they were part of the drainage for Coyote and
Oat creeks and were considered “waters of the United States.”
State officials plan to stop releasing water down the mangled
main spillway at Oroville Dam on Friday, allowing workers to
begin months of round-the-clock repairs to the chute and to an
emergency spillway that is also badly damaged.
A hole in the concrete spillway chute of the Oroville Dam first
made itself known 100 days ago. How it got there is still a
mystery, as is what it will cost to fix the resulting damage
and whether a fix will be in place in time for the next rainy
America’s tallest dam was built from earth, stone and concrete
– and the towering ambition of Gov. Pat Brown. Sixty years
before a crisis at Oroville Dam sent thousands fleeing for
their lives in February, the late governor brought an almost
evangelical zeal to erecting the structure that would hold back
the Feather River to deliver water to the parched southern half
of the state.
There was going to be a steam train – and a monorail. Plus a
major resort featuring a 250-seat restaurant and a 1,000-seat
amphitheater. As many as 5 million visitors a year would show
up. When it came to wooing Butte County about the construction
of Oroville Dam, state officials weren’t shy about setting
Trouble had been developing at the Oroville Dam and the main
spillway had been shut down; water started flowing over the
emergency spillway and the hillside below it started
disintegrating at an alarming rate. Late afternoon on Feb. 12,
evacuation orders were issued. By most people’s accounts, it
didn’t go well.
If a fresh look had been taken at Oroville Dam — any time
between 50 years ago and last year — could the breakup of the
spillway have been avoided? Is enough being done to ensure that
work done today will keep the communities downstream of the dam
safe? Should the Department of Water Resources remain in charge
of the dam in the future?
The amount of money Donald Trump’s administration reimburses
California for repairs to Oroville Dam could depend on whether
the state properly maintained the dam’s spillway prior to it
crumbling this winter, a state water official told lawmakers
As in most of the other community meetings the Department of
Water Resources has conducted about the Oroville Dam spillway
crisis, staff members Tuesday night offered profuse apologies
and community members voiced distrust. … Many of those who
stood to speak said they or their families had also been
present for the floods of the past (1955, 1986, 1997).
There’s more debris in the water at the Oroville Dam Diversion
Pool than initially thought, and state Department of Water
Resources officials now don’t expect to complete dredging and
hauling of debris by December. DWR is seeking bids for the
The massive failure of the Oroville Dam’s main spillway in
February involved two dozen potential design and maintenance
problems, including thin concrete, inadequate reinforcing steel
and weaknesses in the foundation, a panel of engineering
experts reported Wednesday.
In a report released Wednesday, engineers assigned to
investigate the February failure of Oroville Dam’s main
spillway cited a variety of flaws in the 3,000-foot-long
structure, including variations in the thickness of the
concrete slabs, poor drainage beneath the spillway, improperly
filled cracks and signs of inadequate maintenance.
California is putting communities downstream in danger of
flooding with the way it runs the now-crippled Oroville Dam,
mayors and county leaders wrote this week in a strongly worded
letter to Gov. Jerry Brown.
Pursuing exiting the settlement agreement with the state
Department of Water Resources was on the table Tuesday night at
a special meeting of the Oroville City Council, but the
decision was set aside for later. Most of the council expressed
interest in gathering more public opinion on the issue before
taking a vote, with a town hall date set for May 22 at 5:30
p.m. in the Municipal Auditorium.
California is borrowing up to $500 million to pay for the
crisis at Oroville Dam, although it expects to be reimbursed
for its costs. … Kiewit Corp. of Omaha, Neb., has won a
$275.4 million contract for the repairs, which are expected to
take two years.
California is asking the federal government to pay 75 percent
of the hundreds of millions of dollars in repairs to the badly
damaged spillways at the nation’s tallest dam, a state water
agency spokeswoman said Monday.
The independent board overseeing the repair of the damage main
Oroville Dam spillway has recommended the state Department of
Water Resources change its priorities and focus on the damaged
bottom chute rather than the top.
Outside consultants agree with the state’s plan to spend the
next two summers replacing sections of Oroville Dam’s still
largely intact upper spillway rather than trying to tear it all
out in one season. But the public can’t see the recommendations
the independent board of consultants gave the Department of
Water Resources to ensure the work is safe and sound.
Cindy Messer apologized Tuesday to several hundred grim
Oroville residents who had been ordered to run from their homes
three months earlier. They sat rigidly in their seats inside
the Oroville Municipal Auditorium at the first public meeting
Messer’s agency, the Department of Water Resources, has hosted
in Oroville since the February crisis at the dam.
Will there be a viewing platform where the public can watch
work being done on the Oroville spillway? That’s the plan,
according to Cindy Messer, Chief Deputy Director of the
Department of Water Resources.
A power industry consulting firm has proposed a design for the
Oroville Dam spillways which involves not repairing the current
one, but building a new, wider spillway. … Kenneth Viney,
manager of CoastalGen Inc., based in Napa, filed suggestions
Monday with the Federal Energy Regulatory Commission, or FERC.
“I’m sorry. I’m sorry for the impact on your lives,” Bill
Croyle told a crowd of more than 250 people at the Butte County
Fairgrounds. Croyle, the acting director of the Department of
Water Resources, answered questions and listened Thursday
evening as people stepped up to a microphone and were heard
during the first of the water agency’s community meetings about
the Oroville Dam spillway disaster and evacuations.
California officials are keeping another document on the
Oroville Dam recovery sealed from public view but promise to
release a redacted version within a week. The Department of
Water Resources filed an update Thursday from the outside
consultants advising DWR on Oroville repairs.
Two experts weighed in on the memos that the Board of
Consultants assessing the current operations and future
spillway options sent to the Department of Water Resources. …
A former engineer who reviews disasters and a Chico State
University engineering professor reviewed the memos and talked
to this newspaper about their questions, comments and concerns.
Rivers were swift and wide this winter with heavy storms adding
up to the wettest winter in 122 years. People who have lived in
the Sacramento Valley for decades remember flooding from their
youth, when towns were evacuated, homes were lost and topsoil
In 2015, a Nevada County man believed to be running a marijuana
cultivation site hauled a 500-gallon tank into Yuba County and
filled it by diverting water from the Yuba River, which is not
illegal under current law. Yuba County supervisors and the
district attorney recently signed a letter of support for a
bill that would amend the Water Code to address that type of
Members of the state Senate Natural Resources and Water
Committee, at an hourlong oversight hearing on the Oroville
crisis, questioned Secretary John Laird, the head of the
Department of Water Resources and Natural Resources, on the
specifications of the $275 million contract awarded earlier
this month to Kiewit Corp. of Omaha, Neb., to fix the dam’s two
For the first time since the Lake Oroville spillway crisis
began, members of the state Legislature peppered key water
leaders with questions about what happened, what will happen
next and what can be learned from it all.
The head of California’s water agency on Tuesday repeated his
assertion that an emergency spillway at the Oroville Dam
worked, drawing an incredulous response from a state lawmaker
who represents tens of thousands of people ordered to evacuate
when it was feared erosion at the spillway could lead to
A pair of crippled spillways at Oroville Dam can be repaired in
part by November, but a good deal of the work will probably
have to be done after the next rainy season, according to
reports by an independent panel of experts.
The damage has been done and the repair contract awarded. …
How much will be the responsibility of homeowners, businesses,
farmers and other customers of the more than two dozen local
and regional agencies that contract with the State Water
Official reports released Monday say the catastrophic damage to
Oroville Dam’s main spillway probably stemmed from swift water
flows under the concrete chute, which was cracked and of uneven
Responding to criticism about secrecy around the Oroville Dam
repair effort, California officials released two redacted
reports Monday from outside engineers consulting on plans to
fix the dam’s battered spillways.
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.
The water agency that supplies drinking water to Los Angeles
agreed Tuesday to contribute $1.5 million toward the planning
of Sites Reservoir in the Sacramento Valley, giving the agency
a toehold in a potentially valuable storage project.
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
Southern California’s most powerful water agency is prepared to
invest in Sacramento Valley’s proposed Sites Reservoir, a move
that could broaden support for the $4.4 billion project but
also raise alarms about a south state “water grab.”
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.
For the past two years fisheries officials — concerned
about the plummeting numbers of winter-run chinook salmon
— have gone to the state Fish and Game Commission to get
an emergency closure of a section of the Sacramento River in
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.
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.
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.
About one million endangered fish flooded into a stretch of the
Feather River near Yuba City Monday, transported out of the
Thermalito annex of the Feather River Fish Hatchery by the
California Department of Fish and Wildlife and National Oceanic
and Atmospheric Administration National Marine Fisheries
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.
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