Dams seem like a simple idea, but are harder to plan and build
Published: Monday, Apr. 4, 2011 - 12:00 am | Page 1A
As prodigious winter runoff empties into the ocean, Californians who spent the past few years in a drought might see those rivers gushing by and wonder, thirstily, "Why can't we capture that?"
Had we done so in the last wet period, the thinking goes, perhaps we could have tempered the sting of drought. More storage capacity could also reduce flood risk in years when the rain and snow just won't stop.
The idea is simple, but executing it is controversial – and expensive. Large state and federal water storage projects have been in the planning for years, and construction dates remain elusive. Some projects, such as the long-dormant Auburn dam on the American River, have been halted by environmental, safety and financial concerns.
There are new water storage projects under construction in California, but they are exclusively small, locally funded projects, carefully devised to address environmental concerns.
"Developing water today is very expensive," said Michelle Denning, regional planning officer for the U.S. Bureau of Reclamation.
The price of water from new dams carries much of the burden to repay construction cost. The danger: It will be so expensive nobody will want to buy it.
This is the concern with two large projects the federal reclamation agency is studying: Temperance Flat, a new dam on the San Joaquin River; and raising Shasta Dam on the Sacramento River.
In Shasta's case, despite a potential storage increase of 650,000 acre-feet, a dam raise of 18.5 feet would yield an estimated annual new water supply of just 60,000 acre-feet on average, due to the need to preserve flows for fisheries. That could make the potential $1 billion cost difficult to finance.
An acre-foot is enough to supply two average households for a year.
The Shasta Dam project faces another hurdle: State law prohibits any state agency from participating because it would submerge a portion of the McCloud River, designated "wild and scenic."
On the San Joaquin River, the proposed Temperance Flat dam may have trouble penciling out because it would reduce the generating capacity of the Kerckhoff hydroelectric system.
"The only way these two projects would be built is if taxpayers provide massive subsidies," said Jonas Minton, a senior project manager at the Planning and Conservation League, who formerly oversaw water storage investigations at the state Department of Water Resources.
"Environmentally acceptable dams are being built," he said, "when those who benefit put up the money."
That is happening in the hills near Brentwood, on the edge of the Sacramento-San Joaquin Delta, where the Contra Costa Water District this month begins building an expansion of its Los Vaqueros Reservoir.
The existing earthen Vaqueros Dam will be raised 35 feet, increasing capacity from 100,000 acre-feet to 165,000. That extra capacity will be used to store better-quality water pumped from the Delta when it's available so it can be used during dry years.
"We're not using it to supply more houses or more growth," said Greg Gartrell, the district's assistant general manager. Instead, he said, "We'll be able to get through three- to four-year droughts without rationing."
The $118 million project is funded by ratepayers and faced almost no opposition from environmentalists or regulators. That is partly because it will reduce the district's need to draw water from the Delta in dry years, when the estuary is stressed.
Those kinds of environmental benefits are key to any new storage project. Planners are tweaking their projects carefully to find those benefits.
An example is the proposed Sites Reservoir in Colusa County. The 1.8 million acre-foot project near Williams would dam a rural valley and fill it with water pumped from the Sacramento River.
One of the chief benefits: Sites water could be delivered instead of colder water held deep in existing reservoirs such as Shasta and Folsom, allowing that water to be saved instead for salmon runs, said Ajay Goyal, chief of the statewide infrastructure investment branch at the water resources department, the lead agency on the project. "This is taking pressure off the existing reservoirs," Goyal said.
But the $3.6 billion Sites project could still be stalled by lack of money. A draft environmental study is expected by December, at which point DWR is expected to run out of funding to pursue it further, Goyal said.
A joint powers authority of local government agencies was formed to support the project. But no third party has volunteered to buy water from Sites, a critical step to spur construction.
One potential buyer is the Metropolitan Water District of Southern California, which serves about 20 million people in the greater Los Angeles region. But the district is focused instead on improving water flows, or conveyance, through or around the Delta.
The district is the largest urban buyer of Delta water, and its access is hindered at times by rules that protect endangered fish. It has invested tens of millions in studies to improve Delta conveyance as part of a process called the Bay Delta Conservation Plan.
Thanks to this year's high river flows, the district has already refilled its existing storage facilities and is not looking for new ones.
"The storage grid is really functioning very well," said Jeffrey Kightlinger, Metropolitan's general manager. "Our view of the next 10 to 15 years of investment is fixing Delta conveyance and working on local projects like recycling and conservation."
Had we done so in the last wet period, the thinking goes, perhaps we could have tempered the sting of drought. More storage capacity could also reduce flood risk in years when the rain and snow just won't stop.
The idea is simple, but executing it is controversial – and expensive. Large state and federal water storage projects have been in the planning for years, and construction dates remain elusive. Some projects, such as the long-dormant Auburn dam on the American River, have been halted by environmental, safety and financial concerns.
There are new water storage projects under construction in California, but they are exclusively small, locally funded projects, carefully devised to address environmental concerns.
"Developing water today is very expensive," said Michelle Denning, regional planning officer for the U.S. Bureau of Reclamation.
The price of water from new dams carries much of the burden to repay construction cost. The danger: It will be so expensive nobody will want to buy it.
This is the concern with two large projects the federal reclamation agency is studying: Temperance Flat, a new dam on the San Joaquin River; and raising Shasta Dam on the Sacramento River.
In Shasta's case, despite a potential storage increase of 650,000 acre-feet, a dam raise of 18.5 feet would yield an estimated annual new water supply of just 60,000 acre-feet on average, due to the need to preserve flows for fisheries. That could make the potential $1 billion cost difficult to finance.
An acre-foot is enough to supply two average households for a year.
The Shasta Dam project faces another hurdle: State law prohibits any state agency from participating because it would submerge a portion of the McCloud River, designated "wild and scenic."
On the San Joaquin River, the proposed Temperance Flat dam may have trouble penciling out because it would reduce the generating capacity of the Kerckhoff hydroelectric system.
"The only way these two projects would be built is if taxpayers provide massive subsidies," said Jonas Minton, a senior project manager at the Planning and Conservation League, who formerly oversaw water storage investigations at the state Department of Water Resources.
"Environmentally acceptable dams are being built," he said, "when those who benefit put up the money."
That is happening in the hills near Brentwood, on the edge of the Sacramento-San Joaquin Delta, where the Contra Costa Water District this month begins building an expansion of its Los Vaqueros Reservoir.
The existing earthen Vaqueros Dam will be raised 35 feet, increasing capacity from 100,000 acre-feet to 165,000. That extra capacity will be used to store better-quality water pumped from the Delta when it's available so it can be used during dry years.
"We're not using it to supply more houses or more growth," said Greg Gartrell, the district's assistant general manager. Instead, he said, "We'll be able to get through three- to four-year droughts without rationing."
The $118 million project is funded by ratepayers and faced almost no opposition from environmentalists or regulators. That is partly because it will reduce the district's need to draw water from the Delta in dry years, when the estuary is stressed.
Those kinds of environmental benefits are key to any new storage project. Planners are tweaking their projects carefully to find those benefits.
An example is the proposed Sites Reservoir in Colusa County. The 1.8 million acre-foot project near Williams would dam a rural valley and fill it with water pumped from the Sacramento River.
One of the chief benefits: Sites water could be delivered instead of colder water held deep in existing reservoirs such as Shasta and Folsom, allowing that water to be saved instead for salmon runs, said Ajay Goyal, chief of the statewide infrastructure investment branch at the water resources department, the lead agency on the project. "This is taking pressure off the existing reservoirs," Goyal said.
But the $3.6 billion Sites project could still be stalled by lack of money. A draft environmental study is expected by December, at which point DWR is expected to run out of funding to pursue it further, Goyal said.
A joint powers authority of local government agencies was formed to support the project. But no third party has volunteered to buy water from Sites, a critical step to spur construction.
One potential buyer is the Metropolitan Water District of Southern California, which serves about 20 million people in the greater Los Angeles region. But the district is focused instead on improving water flows, or conveyance, through or around the Delta.
The district is the largest urban buyer of Delta water, and its access is hindered at times by rules that protect endangered fish. It has invested tens of millions in studies to improve Delta conveyance as part of a process called the Bay Delta Conservation Plan.
Thanks to this year's high river flows, the district has already refilled its existing storage facilities and is not looking for new ones.
"The storage grid is really functioning very well," said Jeffrey Kightlinger, Metropolitan's general manager. "Our view of the next 10 to 15 years of investment is fixing Delta conveyance and working on local projects like recycling and conservation."
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