A New Earthquake-Proof Calaveras Dam – KQED QUEST


Man: OKAY. Narrator: LESS THAN A MILE FROM
MISSION BOULEVARD IN FREMONT, ENGINEERS WITH THE SAN FRANCISCO
PUBLIC UTILITIES COMMISSION ARE DESCENDING DEEP UNDERGROUND
TO INSPECT THE PROGRESS ON A NEW TUNNEL. Wade: WE’LL HAVE TO TIE IN
THIS PIECE RIGHT HERE IN THE SHAFT FIRST,
WELD THIS IN PLACE, BACKFILL CONCRETE IT. Narrator: THIS NINE-FOOT
DIAMETER TUNNEL IS NOW OPEN, CARRYING ON AVERAGE 62,000
GALLONS OF WATER A MINUTE EACH DAY
TO FOUR BAY AREA COUNTIES. IT’S A KEY STEP IN UPGRADING
AND REPLACING PARTS OF A SYSTEM THAT HAS SERVED THE BAY AREA
FOR 80 YEARS. Wade: WE’RE HERE
AT THE NEW IRVINGTON TUNNEL. THIS IS ONE OF THE MOST
CRITICAL PIECES OF OUR SYSTEM BECAUSE WHEN WE’RE DONE AND WE
PUT THIS TUNNEL INTO SERVICE, IT’S GOING TO CARRY WATER THAT SERVES 2.6 MILLION PEOPLE
IN THE BAY AREA. Narrator: DAN WADE
IS THE DIRECTOR OF THE HETCH HETCHY WATER
SYSTEM IMPROVEMENT PROGRAM. AT A COST
OF NEARLY $5 BILLION DOLLARS, IT’S ONE OF
THE LARGEST ENGINEERING PROJECTS IN THE NATION. Wade: THE NEW IRVINGTON TUNNEL
IS STEEL-LINED, AND IT
HAS A CONCRETE REINFORCEMENT, AND THAT ENSURES THAT WE HAVE A RELIABLE
EARTHQUAKE-RESISTANT TUNNEL WELL INTO THE FUTURE. Narrator: THE SAN FRANCISCO
PUBLIC UTILITIES COMMISSION IS IN CHARGE
OF MAKING SURE THE TAPS KEEP FLOWING WITH THIS WATER. IT ORIGINATES 167 MILES
AWAY AT HETCH HETCHY RESERVOIR IN YOSEMITE. BUT MUCH OF THE SYSTEM WAS BUILT
IN THE 1920s AND ’30s. TODAY, A MAJOR EARTHQUAKE COULD LEAVE PARTS OF THE BAY
AREA WITHOUT WATER FOR A MONTH. Wade:
ONE OF THE PRIMARY GOALS OF THE WATER SYSTEM
IMPROVEMENT PROGRAM IS TO ENSURE
THAT WITHIN 24 HOURS AFTER A MAJOR EARTHQUAKE, WE WILL BE ABLE TO DELIVER WATER
TO THE CUSTOMERS. Narrator: AND TO PAY FOR IT, WATER RATES HAVE BEEN
GOING UP — WAY UP — FOR THE SYSTEM’S CUSTOMERS WHO LIVE IN SAN FRANCISCO,
SAN MATEO, ALAMEDA, AND SANTA CLARA COUNTIES. Wade: ONE-THIRD OF THE CUSTOMERS
LIVE IN SAN FRANCISCO, AND SO THEY’RE GOING
TO PAY ONE-THIRD OF THE BILL, AND THE OTHER TWO-THIRDS
WILL BE PAID BY OUR CUSTOMERS OUTSIDE OF SAN FRANCISCO. SAN FRANCISCO RESIDENTS
WILL SEE THEIR WATER RATES APPROXIMATELY TRIPLE BY THE TIME
THE PROGRAM IS DONE. Narrator: THE VOTER-APPROVED
PROGRAM BEGAN IN 2004 AND IS SCHEDULED TO END IN 2018. BUT THERE’S URGENCY
TO GET IT DONE. Wade:
WE HAVE THE CALAVERAS FAULT, THE HAYWARD FAULT
IN THE EAST BAY, AND THEN OF COURSE,
THE SAN ANDREAS FAULT
ON THE PENINSULA. AND OUR WATER SYSTEM CROSSES
ALL THREE OF THOSE MAJOR FAULTS. THE U.S. GEOLOGICAL SURVEY,
A FEW YEARS AGO, PREDICTED THAT BY 2035, THERE’S MORE THAN A 63% CHANCE THAT THERE’D BE A MAJOR
EARTHQUAKE HERE IN THE BAY AREA. SO WE’RE TRULY IN A RACE
AGAINST TIME. Man: CESAR, YOU GOT A COPY?
CESAR? Narrator:
THE WORK IS ON TRACK, AND OCCASIONALLY,
EVEN AHEAD OF SCHEDULE. Wade: ONE OF OUR MOST IMPRESSIVE
PROJECTS IS THE NEW BAY TUNNEL, A FIVE-MILE PIPELINE UNDERNEATH
THE SAN FRANCISCO BAY, AND IT’S THE FIRST TRUE TUNNEL THAT’S BEEN CONSTRUCTED
UNDERNEATH THE BAY. Narrator: TO HELP
SHIELD IT FROM THE SHAKING DURING AN EARTHQUAKE, THE TEAM BUILT THIS NEW TUNNEL IN A BED OF THICK CLAY 100 FEET
BENEATH SAN FRANCISCO BAY. IT REPLACES TWO PIPELINES
BUILT IN 1925 AND 1936, AND CARRIES WATER
FROM THE EAST BAY TO SAN FRANCISCO
AND THE PENINSULA. Wade:
THE HETCH HETCHY WATER SYSTEM HAS BEEN SERVING US VERY WELL
THROUGHOUT THE 20th CENTURY AND INTO THE 21st. HOWEVER, THE INFRASTRUCTURE
IS OLD. IT’S AGING, IT’S IN NEED
OF REPAIR OR REPLACEMENT OR UPGRADES. Narrator: WITH MOST
OF THE ROUGHLY 80 UPGRADES AND REPLACEMENTS DONE, THE CONSTRUCTION CREWS
ARE HARD AT WORK ON THE TOUGHEST
AND BIGGEST PROJECT OF THEM ALL. Wade: CALAVERAS DAM WAS BUILT
IN 1925. IT FORMS CALAVERAS RESERVOIR, WHICH IS
THE LARGEST LOCAL RESERVOIR THAT’S PART OF OUR SYSTEM. WE NEEDED TO PERMANENTLY
RESTRICT THE RESERVOIR LEVEL TO ABOUT 40% OF CAPACITY. Narrator:
THIS NEW DAM IS BEING BUILT NEAR THE ALAMEDA-SANTA CLARA
COUNTY LINE OUT OF EARTH AND ROCK,
LIKE THE OLD DAM. THE NEW DAM, HOWEVER,
WILL BE SEISMICALLY STRONGER, WHICH WILL ALLOW
THE CALAVERAS RESERVOIR TO FILL TO CAPACITY —
31 BILLION GALLONS. Wade: CALIFORNIA IS
IN A SEVERE DROUGHT. WE NEED THIS RESERVOIR
FOR DROUGHT CARRYOVER STORAGE. THE PROGRAM HAS A GOAL OF MEETING A DROUGHT PERIOD
OF SEVEN AND A HALF YEARS TO ENSURE THAT WE CAN CONTINUE
TO SUPPLY WATER TO OUR CUSTOMERS IN THAT LENGTH OF DROUGHT. Narrator: AS BULLDOZERS
EXCAVATE DIRT AND ROCK TO CARVE OUT
THE 220-FOOT-TALL DAM, LONG-BURIED TREASURES FROM
THE BAY AREA’S PREHISTORIC PAST ARE COMING TO LIGHT. Walker: EVERY DAY I COME OUT
HERE, I’M VERY EXCITED. I GET TO LOOK FOR FOSSILS FROM CREATURES
THAT LIVED 20 MILLION YEARS AGO. TODAY, WE FOUND TWO VERTEBRAE
FROM A WHALE. PROBABLY BETWEEN THE SIZE OF A LARGE DOLPHIN
AND A KILLER WHALE. IN THE PAST,
WE’VE FOUND SHARKS’ TEETH. THIS IS THE TOOTH
OF A MEGALODON. IT’S A PREHISTORIC SHARK THAT LIVED ABOUT 20 MILLION
YEARS AGO. THIS INDIVIDUAL,
BASED ON THE TOOTH SIZE, WOULD HAVE BEEN
ABOUT 25 TO 30 FEET LONG. TO DATE,
WE HAVE OVER 650 FOSSILS. Narrator: NEARBY, THE CREWS
SCOUR THE VALLEY’S WALLS TO MAKE ROOM FOR THE NEW
WATERTIGHT FOUNDATION. BUT A REMINDER WILL STILL STAND
OF WHAT WAS ONCE THE WORLD’S LARGEST
EARTH AND ROCK DAM. Wade: WHEN THIS NEW DAM
IS COMPLETE IN 2018, WE’LL ACTUALLY CUT A NOTCH
AND REMOVE ABOUT ONE-THIRD OF THE EXISTING DAM
SO THAT THE RESERVOIR CAN COME UP AGAINST THE FACE
OF THE NEW DAM. Narrator:
DAN WADE AND HIS TEAM ARE MORE THAN HALFWAY
DONE REPLACING THE DAM, A CRITICAL STEP IN PROTECTING
HETCH HETCHY’S WATER FROM A BIG QUAKE
THAT COULD STRIKE AT ANY MOMENT. Wade: WATER IS A PRECIOUS
RESOURCE. WE CANNOT LIVE WITHOUT IT. WE’RE DOING SOMETHING THAT’S
GOING TO HAVE A LASTING EFFECT, TO ENSURE THE LONG-TERM HEALTH
AND SAFETY, AND ECONOMIC VIABILITY
OF THE SAN FRANCISCO BAY AREA.

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