The highs and the lows of it

The highs and the lows of it
Motorists travel across a span of bridge on Interstate 15, where in the past water from Lake Hodges would be, but has since sprouted a small forest of shrubs, trees and brush. Photo by Tony Cagala

Questions rise as the water level of Lake Hodges continues to fall

REGION — Residents living in sight of the Lake Hodges Reservoir, which stretches from Interstate 15 all the way west towards Del Dios Highway, have seen its highs and lows over the years.

Rainy seasons have filled the reservoir beyond its water level capacity, losing much needed water as it spilled over the dam.

Extremely dry seasons have dropped the level so low as to reveal the lake bed in some areas, allowing a small forest of trees to sprout up.

But after an SDCWA (San Diego County Water Authority) project costing millions of dollars and years of blasting and construction to create the Olivenhain Reservoir and dam, and connect it to Hodges — a project designed, in part, to maintain more consistent levels at Hodges — some residents are asking why the water level continues to shrink.

This year, its 27 shoreline miles are again showing signs of another dry season.

Historically, the water levels at Hodges have fluctuated widely from year to year, according to Arian Collins, supervising public information officer with the San Diego Public Utilities Department.

The lake is owned by the city of San Diego and has, as of last year been drafting water from the reservoir for some of its customers.

Frank Belock, deputy general manager of SDCWA, said that much of the reservoir’s dropping water level can be attributed to the water evaporating. “Hodges…compared to most of the reservoirs in the county, is shallow and broad. Depending on how full it is, it evaporates probably between five to six feet a year.”

A dock sits on the shoreline of Lake Hodges near Del Dios. The shoreline of the reservoir is showing signs of another dry season. Photo by Tony Cagala

A dock sits on the shoreline of Lake Hodges near Del Dios. The shoreline of the reservoir is showing signs of another dry season. Photo by Tony Cagala

Belock added that over the last 30 years, they’ve seen the water levels fluctuate anywhere between 70 feet deep to 115 feet (which is its fullest depth).

At the time of printing, the reservoir was listed at 36.7 percent full on the county’s public works website; the reservoir is the fourth lowest in capacity of the nine reservoirs in the county.

“This is mainly due to the fact that its water level was entirely dependent upon local rain and runoff to fill it,” Belock said.

In the early 2000s SDCWA began work on the Emergency Storage Project.

Costing $1.46 billion, the project is comprised of numerous water-saving improvements at several sites designed to protect the county’s water supply in the event of a natural disaster or other issue that would essentially cut off all water supplies to the county.

“The Water Authority issued debt to pay for all of our capital projects as well as uses Water Authority funds from capacity charges,” said Belock. “The debt service payments are reflected in the Water Authority rates.”

Work on the Hodges project began in 2005 and included the construction of the Olivenhain Reservoir north of Del Dios and the Hodges Pump Station and Hydroelectric Facility.

Pipes traveling 1.25 miles underground connected to the two reservoirs together, allowing them to share water.

“The reason the lake level is low,” Belock said, “is because of the lack of rainfall last year and that the city of San Diego has transferred about 2,700 acre-feet to elsewhere in its system. We have limited our movement of water into Lake Hodges to that which is necessary to operate the turbines in the Lake Hodges Pumped Storage facility.”

There is a minimum water level required to operate the pump storage process where electricity is generated. The water level needed to generate the electricity (about 40 megawatts of peak energy) is probably pretty close to where it is now, Belock added.

And if the water dips below a minimum level?

“What we’ve been doing is, we’ve done it once or twice…we bring water down from Olivenhain, just to keep the water at the minimum,” Belock said.

He added that costs to move water from Olivenhain to Lake Hodges is actually profitable because of the hydroelectric facility.

“The costs to operate the facility are minimal,” he said.

According to a fall 2006 newsletter, part of the ESP goal was to keep Hodges at a more consistent water level. Belock has said that that goal has not changed.

“At the present time up until the completion of the San Vicente Dam Raise project, the Water Authority will not have any capacity in Lake Hodges. After the San Vicente Dam Raise project is completed, of the 32,000 acre-feet capacity in Lake Hodges, the Water Authority will control 20,000 acre-feet of storage in an ESP event.”

The Hodges Reservoir serves as a water source for the Santa Fe Irrigation District, the San Dieguito Water District and, as of last year, the city of San Diego.

With the city having started drafting water from the Hodges Reservoir in March 2012, Collins said on average, the city expects to draft between 5,000 and 6,000 acre feet of water per year.

Now, Hodges is being kept at a certain level (between 90 feet and 100 feet deep), according to Collins, which helps prepare them as winter approaches.

Trish Boaz, executive director of the San Dieguito River Valley Conservancy said that because of the water level, they have concerns about the habitat values being maintained for the water fowl.

“It’s a very important area on the flyway for bird species and we’re concerned about water quality issues, as well,” she said.

In October, SDCWA staff issued an assessment to its board of directors saying that the county will have “sufficient water supplies for 2014, even if dry conditions persist.”

The assessment added that the water authority isn’t anticipating the need for extraordinary conservation measures or water shortage allocations in 2014.

 

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Filed Under: Rancho Santa Fe Lead Story

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