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"We've lost the aqueduct": How severe flooding threatens a Los Angeles water lifeline
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Browndoggles
Mar 28, 2023, 1:02:33 AM3/28/23
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OLANCHA, Calif. — For more than 100 years, the Los Angeles Aqueduct has
endured earthquakes, flash floods and dozens of bomb attacks as it wends
and weaves through the canyons and deserts of the eastern Sierra Nevada.
But earlier this month, record storms accomplished the unthinkable when
floodwaters undermined a 120-foot-long section of aqueduct in Owens
Valley, causing its concrete walls to crumble.
“We’ve lost the aqueduct!” a Los Angeles Department of Water and Power
inspector told his superiors by cellphone. As he spoke, chocolate-colored
runoff and debris undercut the aqueduct just west of Highway 395 and the
community of Olancha.
It was the first time in history that the 200-mile aqueduct had been
breached by extreme weather, threatening water deliveries to 4 million
ratepayers in Los Angeles.
It was also an indication of just how difficult it would be to defend the
waterway against torrential runoff from a winter of near record snowpack.
For weeks, DWP crews had been using heavy equipment and other means to
control the anticipated spring runoff, but even longtime aqueduct workers
were shocked by the suddenness of the break.
Among the first to arrive on the scene that March 10 morning was a team
led by Ben Butler, senior aqueduct and reservoir keeper.
“Floodwater was coming down hard, creating a large, deep pool that pressed
against the aqueduct’s walls,” he recalled. “We drove in as far as we
could, then put on waders and headed for the breach.”
For the next five days, rescuing L.A.’s water lifeline became the DWP’s
highest priority as all hell broke loose in Owens Valley.
Traditionally dry rocky arroyos and ditches were overrunning their banks;
irrigation diversions and culverts were buried in mud the consistency of
peanut butter. At Pleasant Valley Dam, about 8 miles north of the city of
Bishop, stormwater laden with sediment was surging over its spillway and
into the Owens River at a rate of 1,000 cubic feet per second.
“We were already in an all-hands-on-deck mode when we learned that the
aqueduct was in serious trouble,” said Adam Perez, deputy manager of
aqueduct operations. “By 3 p.m. that afternoon, we came up with a game
plan to prevent further deterioration, patch the breach and maintain
service.”
As an emergency action, the DWP opened aqueduct spill gates 25 miles north
to drain the damaged section and make repairs.
Those massive releases were not without consequence however. Freed water
flooded ranches on the valley floor, as well as a half-mile stretch of
state Highway 136, just south of the community of Lone Pine, and surged
toward spreading grounds in Owens Lake, where it caused more problems.
The lake, which was once navigated by steamboats, had evaporated into
dusty salt flats after the aqueduct was completed in 1913. In recent
years, the DWP has spent $2.5 billion on projects designed to prevent the
lakebed’s health-damaging particulate matter from becoming airborne.
But as aqueduct inflows washed over the playa, they dissolved alkaline
minerals there, creating a vast corrosive brine pool that could ruin some
of the dust control projects, officials said.
Over all, it took more than 100 DWP personnel working nonstop for nearly a
week to repair the aqueduct. Their work included replacing damaged
concrete walls and coating them with a special mix of cement, sand,
fibrous material and adhesives that dry faster and harder than
conventional concrete.
“It wasn’t easy managing that many boots on the ground in a short amount
of time amid unfavorable conditions,” Perez said. “Ultimately, the damage
did not affect any communities in the area.”
Nodding appreciatively toward the cargo of Sierra snowmelt flowing high
and fast through the repaired section of channel on Thursday, he added,
“Our crews did a great job.”
Looking ahead, he said, DWP inspectors will be stepping up daily patrols
of its aqueduct systems and dams in Owens Valley.
In the wake of the crisis however, critics are pointing to the breach and
subsequent flooding of the valley floor as signs that the DWP is losing
control of its massive and complex aqueduct infrastructure amid climate-
driven weather extremes.
A singular feat of civil engineering and deception, the aqueduct has both
spurred the phenomenal growth of Los Angeles and inspired deep-seated
suspicions about the city’s motives that linger to this day in Owens
Valley.
Most of its water is diverted from the Owens River, which ran through a
valley that was inhabited for thousands of years by Paiute Indians before
white settlers occupied their lands.
In 1905, city of Los Angeles agents posing as ranchers and farmers
acquired most of the land and water rights in Owens Valley and
construction of the system of tunnels, conduits and reservoirs began in
1907.
By the early 1920s, tensions seethed in the area over the city’s
continuing acquisitions. Over a three-year period, the aqueduct was
dynamited more than a dozen times.
On Sept. 15, 1976, a dynamite blast ripped apart one of the Alabama Hills
aqueduct gatehouse’s five gates, flushing 100 million gallons of water
into the valley floor.
Today, the chatter at local cafes and watering holes is over whether the
DWP will be up to the task of managing levels of flooding expected this
spring and summer.
Some residents are encouraged by the sight of caravans of DWP-owned earth
movers and dump trucks loaded with boulders and mud rumbling to and from
flood zones.
“We’ve had a lot of rain, snow and temperature swings lately,” said Dan
Siegel, owner of the Merry-go-Round restaurant in Lone Pine. “I think the
DWP has been doing a fine job when you consider how many places are in
need of its equipment and manpower.”
As for predictions of potentially massive flooding when temperatures climb
into the 80s and 90s, “We won’t know how much trouble we’re in until we
know how fast the snow is melting,” Siegel said.
The DWP’s system is starting to show signs of age. In recent years,
several stretches of the aqueduct system have been drained to allow
replacement of cracked and bulging sections of century-old concrete.
Since severe storms began lashing the eastern Sierra region in January,
the DWP has been relying on tactical strategies developed during epic
rainfall that ended a five-year drought in 2017.
DWP crews are racing to clean out clogged culverts, divert excessive
runoff into pasturelands and sage plains, and build berms to steer flood
water from small towns straddling U.S. Highway 395 including Olancha,
Cartago, Lone Pine, Big Pine and Bishop.
Gazing at snow-clad Sierra peaks to the west, Perez said, “If all that
snow comes down hot and heavy when the weather warms up, the challenge
will be to protect Owens Valley’s communities from flooding.”
There is a silver lining to the situation, however: For the first time in
six years, Los Angeles can expect to receive a majority of its water from
the aqueduct at least through late fall, Perez said.
Only a year ago, at the tail end of the worst drought in 1,200 years, the
aqueduct was delivering about 13% of the city’s water supplies, with much
of the rest purchased from the State Water Project and the Colorado River.
<https://www.latimes.com/environment/story/2023-03-25/eastern-sierra-
flooding-threatens-los-angeles-water-lifeline>
endured earthquakes, flash floods and dozens of bomb attacks as it wends
and weaves through the canyons and deserts of the eastern Sierra Nevada.
But earlier this month, record storms accomplished the unthinkable when
floodwaters undermined a 120-foot-long section of aqueduct in Owens
Valley, causing its concrete walls to crumble.
“We’ve lost the aqueduct!” a Los Angeles Department of Water and Power
inspector told his superiors by cellphone. As he spoke, chocolate-colored
runoff and debris undercut the aqueduct just west of Highway 395 and the
community of Olancha.
It was the first time in history that the 200-mile aqueduct had been
breached by extreme weather, threatening water deliveries to 4 million
ratepayers in Los Angeles.
It was also an indication of just how difficult it would be to defend the
waterway against torrential runoff from a winter of near record snowpack.
For weeks, DWP crews had been using heavy equipment and other means to
control the anticipated spring runoff, but even longtime aqueduct workers
were shocked by the suddenness of the break.
Among the first to arrive on the scene that March 10 morning was a team
led by Ben Butler, senior aqueduct and reservoir keeper.
“Floodwater was coming down hard, creating a large, deep pool that pressed
against the aqueduct’s walls,” he recalled. “We drove in as far as we
could, then put on waders and headed for the breach.”
For the next five days, rescuing L.A.’s water lifeline became the DWP’s
highest priority as all hell broke loose in Owens Valley.
Traditionally dry rocky arroyos and ditches were overrunning their banks;
irrigation diversions and culverts were buried in mud the consistency of
peanut butter. At Pleasant Valley Dam, about 8 miles north of the city of
Bishop, stormwater laden with sediment was surging over its spillway and
into the Owens River at a rate of 1,000 cubic feet per second.
“We were already in an all-hands-on-deck mode when we learned that the
aqueduct was in serious trouble,” said Adam Perez, deputy manager of
aqueduct operations. “By 3 p.m. that afternoon, we came up with a game
plan to prevent further deterioration, patch the breach and maintain
service.”
As an emergency action, the DWP opened aqueduct spill gates 25 miles north
to drain the damaged section and make repairs.
Those massive releases were not without consequence however. Freed water
flooded ranches on the valley floor, as well as a half-mile stretch of
state Highway 136, just south of the community of Lone Pine, and surged
toward spreading grounds in Owens Lake, where it caused more problems.
The lake, which was once navigated by steamboats, had evaporated into
dusty salt flats after the aqueduct was completed in 1913. In recent
years, the DWP has spent $2.5 billion on projects designed to prevent the
lakebed’s health-damaging particulate matter from becoming airborne.
But as aqueduct inflows washed over the playa, they dissolved alkaline
minerals there, creating a vast corrosive brine pool that could ruin some
of the dust control projects, officials said.
Over all, it took more than 100 DWP personnel working nonstop for nearly a
week to repair the aqueduct. Their work included replacing damaged
concrete walls and coating them with a special mix of cement, sand,
fibrous material and adhesives that dry faster and harder than
conventional concrete.
“It wasn’t easy managing that many boots on the ground in a short amount
of time amid unfavorable conditions,” Perez said. “Ultimately, the damage
did not affect any communities in the area.”
Nodding appreciatively toward the cargo of Sierra snowmelt flowing high
and fast through the repaired section of channel on Thursday, he added,
“Our crews did a great job.”
Looking ahead, he said, DWP inspectors will be stepping up daily patrols
of its aqueduct systems and dams in Owens Valley.
In the wake of the crisis however, critics are pointing to the breach and
subsequent flooding of the valley floor as signs that the DWP is losing
control of its massive and complex aqueduct infrastructure amid climate-
driven weather extremes.
A singular feat of civil engineering and deception, the aqueduct has both
spurred the phenomenal growth of Los Angeles and inspired deep-seated
suspicions about the city’s motives that linger to this day in Owens
Valley.
Most of its water is diverted from the Owens River, which ran through a
valley that was inhabited for thousands of years by Paiute Indians before
white settlers occupied their lands.
In 1905, city of Los Angeles agents posing as ranchers and farmers
acquired most of the land and water rights in Owens Valley and
construction of the system of tunnels, conduits and reservoirs began in
1907.
By the early 1920s, tensions seethed in the area over the city’s
continuing acquisitions. Over a three-year period, the aqueduct was
dynamited more than a dozen times.
On Sept. 15, 1976, a dynamite blast ripped apart one of the Alabama Hills
aqueduct gatehouse’s five gates, flushing 100 million gallons of water
into the valley floor.
Today, the chatter at local cafes and watering holes is over whether the
DWP will be up to the task of managing levels of flooding expected this
spring and summer.
Some residents are encouraged by the sight of caravans of DWP-owned earth
movers and dump trucks loaded with boulders and mud rumbling to and from
flood zones.
“We’ve had a lot of rain, snow and temperature swings lately,” said Dan
Siegel, owner of the Merry-go-Round restaurant in Lone Pine. “I think the
DWP has been doing a fine job when you consider how many places are in
need of its equipment and manpower.”
As for predictions of potentially massive flooding when temperatures climb
into the 80s and 90s, “We won’t know how much trouble we’re in until we
know how fast the snow is melting,” Siegel said.
The DWP’s system is starting to show signs of age. In recent years,
several stretches of the aqueduct system have been drained to allow
replacement of cracked and bulging sections of century-old concrete.
Since severe storms began lashing the eastern Sierra region in January,
the DWP has been relying on tactical strategies developed during epic
rainfall that ended a five-year drought in 2017.
DWP crews are racing to clean out clogged culverts, divert excessive
runoff into pasturelands and sage plains, and build berms to steer flood
water from small towns straddling U.S. Highway 395 including Olancha,
Cartago, Lone Pine, Big Pine and Bishop.
Gazing at snow-clad Sierra peaks to the west, Perez said, “If all that
snow comes down hot and heavy when the weather warms up, the challenge
will be to protect Owens Valley’s communities from flooding.”
There is a silver lining to the situation, however: For the first time in
six years, Los Angeles can expect to receive a majority of its water from
the aqueduct at least through late fall, Perez said.
Only a year ago, at the tail end of the worst drought in 1,200 years, the
aqueduct was delivering about 13% of the city’s water supplies, with much
of the rest purchased from the State Water Project and the Colorado River.
<https://www.latimes.com/environment/story/2023-03-25/eastern-sierra-
flooding-threatens-los-angeles-water-lifeline>
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