The price of an enormous mission to rebuild Anderson Dam, close to Morgan Hill, proven right here in April 2020, has elevated from $648 million to $1.2 billion. (Picture: Santa Clara Valley Water District)
Within the newest setback for a mission that has been fraught with delays and price overruns for greater than a decade, the value tag to rebuild Anderson Dam — Santa Clara County’s largest — to enhance earthquake security is sort of doubling, from $648 million to $1.2 billion.
The information comes one yr after the Santa Clara Valley Water District, the federal government company that owns the dam close to Morgan Hill, introduced that one other of its giant development plans, a proposal to construct an enormous new reservoir close to Pacheco Cross, additionally had doubled in value, from $1.3 billion to $2.5 billion.
“It’s horrible information,” mentioned Tony Estremera, chairman of the district, on Thursday of the Anderson price will increase. “It’s simply gotten worse and worse.”
Water fee will increase pays for the extra prices, Estremera mentioned. The board of the district, which supplies consuming water and flood management to 2 million folks in Santa Clara County, will maintain a particular assembly on Monday in San Jose to debate the problem.
However pulling the plug on Anderson Dam’s rebuilding isn’t an choice, Estremera mentioned.
The 240-foot excessive earthen dam, in-built 1950 close to Freeway 101 between Morgan Hill and San Jose, is a key a part of Silicon Valley’s water system, and the tallest dam in Santa Clara County. When its reservoir is full, Anderson holds 89,278 acre ft of water — greater than the water district’s different 9 reservoirs mixed.
The district drained it a yr in the past underneath orders from federal dam security regulators. Crews broke floor in July on the primary a part of the restore job, constructing an enormous new outlet tunnel, which is scheduled to be accomplished in 2024. Your complete job to rebuild the dam and spillway gained’t be completed till 2030.
“There’s no query we've got to do it,” Estremera mentioned. “This can be a precedence. It’s a security mission.”
The employees of the district mentioned Thursday that the fee overruns are a results of higher-than-expected labor and supplies prices, and stringent necessities to boost fish and wildlife by federal and state businesses that should concern permits for the large mission.
“It’s unlucky, but it surely’s essential,” mentioned Chris Hakes, the district’s deputy working officer for dam security. “It’s the kind of factor the place if we'd have constructed this in 1950 all of the regulators wouldn’t have been concerned and it could go faster, however it could be extra environmentally pricey when it comes to harm.”
Critics mentioned the district too typically has pricey overruns and isn't a superb steward of public cash.
“That is the usual modus operandi for these people,” mentioned Mark Hinkle, president of the Silicon Valley Taxpayers Affiliation. “There’s all the time extra money that they want. It’s by no means sufficient.”
Hinkle mentioned an outdoor auditor or investigator, just like the Santa Clara County Civil Grand Jury, ought to look into the repeated delays and price overruns on the Anderson Dam mission.
When the district constructed the dam in 1950, scientists thought the close by Calaveras Fault was inactive. And water district officers believed that the dam was anchored in bedrock.
However an engineering agency performing checks required by federal regulators in December 2008 discovered that the dam’s basis incorporates sand and gravel, which may shift in a significant quake. Particularly, a 6.6 magnitude quake on the Calaveras Fault instantly at Anderson Reservoir, or a 7.2 quake centered one mile away, may trigger the massive earthen dam to stoop and fail.
Though unlikely, a whole failure of Anderson Dam when the reservoir is full may ship a 35-foot wall of water into downtown Morgan Hill inside 14 minutes, engineers concluded. The waters could be 8-feet deep in San Jose inside three hours, probably killing 1000's of individuals.
At first, in 2011, the district deliberate to strengthen the present dam. Then, district officers mentioned the fee could be $193 million, with development starting in 2017 and taking three years. However new hint faults discovered within the space required a brand new dam to be constructed, doubling the value by 2016 to $400 million.
Now the value is thrice larger.
“The cash we spend now's going to be a drop within the bucket in comparison with what we'd have spent if we fastened it later,” Hakes mentioned. “Or if there was an emergency. If one thing occurred to the dam, it could be catastrophic to Silicon Valley.”
Annoyed on the sluggish tempo and alarmed by the near-failure of Oroville Dam in Butte County throughout main storms in 2017, the Federal Vitality Regulatory Fee in February 2020 issued a dramatic order requiring the district to empty Anderson and restore it.
Simply earlier than that, the district had drawn up a $563 million plan to rebuild the dam, a brand new outlet tunnel and new spillway over 5 years, between 2022 and 2027. However Hakes famous that when federal regulators issued their order to empty Anderson, in addition they required the district to construct the outlet tunnel first to make sure the reservoir might be drained rapidly in an especially moist yr.
Breaking the mission into two segments — the tunnel and the dam rebuilding afterward — elevated the timeline from 5 to 10 years, he mentioned, which has additional raised the value tag.
To pay the invoice, Estremera mentioned the district’s board might should delay different tasks, together with flood management work and the proposed Pacheco Dam.
“We’re making an attempt our greatest,” he mentioned. “We’ll have to have a look at different tasks to see how we will steadiness it out. We’re hoping we will get some assist from the feds or the state, however you by no means understand how issues are going to go.”
