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Hodges Reservoir Will be Closed for Recreation During Five-Month Project

In the coming weeks, the City of San Diego will begin emergency repairs on the Lake Hodges Dam at the Hodges Reservoir in Escondido outside of Rancho Santa Fe.

During a recent inspection, the city identified areas in the dam wall that require repair and need be sealed. In order to complete the work, the water level of the reservoir needs to be lowered by about 18 feet from its current level to an elevation of 275 feet.

The repair project is expected to continue for an estimated five months.

Repair Work on Hodges Dam to Begin

As part of continuing efforts to maintain and invest in City of San Diego infrastructure, repair work starts within the next two weeks on Hodges Dam, at the Hodges Reservoir north of Rancho Bernardo.

“It’s been over a century since Hodges Dam was constructed, and we are making significant investments to maintain this vital asset,” said Alia Khouri, Deputy Chief Operating Officer.

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Repair Work on Hodges Dam to Begin

As part of continuing efforts to maintain and invest in City of San Diego infrastructure, repair work starts within the next two weeks on Hodges Dam, at the Hodges Reservoir north of Rancho Bernardo.

“It’s been over a century since Hodges Dam was constructed, and we are making significant investments to maintain this vital asset,” said Alia Khouri, Deputy Chief Operating Officer. “Projects like this one are crucial for the City’s aging infrastructure system in order to maintain the safe and efficient delivery of City services.”

During a recent inspection, staff identified areas in the dam wall that require repair and need to be sealed. To access these areas, the water level of the reservoir needs to be lowered by approximately 18 feet from its current level to an elevation of 275 feet. The reservoir may need to be lowered below 275 feet if additional areas needing repair are identified during the project. The repair project is expected to continue for an estimated five months.

Water transfers to maximize savings

The Hodges Dam, shown here in 1929, was built in 1918. Photo: UCSD

The Hodges Dam, shown here in 1929, was built in 1918. Photo: UC San Diego

The primary function of Hodges Reservoir is to store water for potable use. The City is working with its regional water agency partners on a plan to draw down the reservoir level to maximize water savings. Most, if not all, of the water will be transferred to other reservoirs, while some water may be released into the San Dieguito River.

“The City of San Diego is committed to maintaining Hodges Dam to ensure the protection of our water resources and public enjoyment of the reservoir,” said Juan Guerreiro, Interim Director of the City’s Public Utilities Department. “We appreciate the public’s patience while we complete the project.”

To access areas of the Hodges Dam for repairs, the water level of the reservoir needs to be lowered by approximately 18 feet from its current level to an elevation of 275 feet. As a result of the lower water level, the Hodges Reservoir will be closed for recreation while the repair project is underway. Boating and fishing will still be available at other City of San Diego reservoirs. The San Dieguito River Park trails and facilities around Hodges Reservoir will not be impacted during the drawdown or dam construction work.

Operated and maintained by the San Diego Public Utilities Department, the reservoir currently serves the San Diego County Water Authority, San Dieguito Water District, and Santa Fe Irrigation District, and the City of San Diego. San Diego operates nine reservoirs, including Hodges.

(Editor’s note: The City of San Diego, San Dieguito Water District, and the Santa Fe Irrigation District are three of the San Diego County Water Authority’s 24 member agencies that deliver water across the metropolitan San Diego region.)

Lake Hodges Water Levels Dry Up Prospects for Grebes

For years, pairs of grebes would zoom across the water at Lake Hodges in a dazzling mating dance, and then build their nests on mats of dried brush suspended above the waterline.

923 Million Gallons of Water Released From Hodges Reservoir After Storm

Because of recent heavy rainfall, the city of San Diego Saturday began releasing about 923 million gallons of water from Hodges Reservoir into the San Dieguito River, which may eventually lead to the ocean, city officials said.

The dam release began at about 11 a.m. Saturday and will continue for about seven days or until the reservoir elevation is near 295 feet, spokesperson José Ysea said.

For safety reasons, the California Division of Safety of Dams has determined that the water level at Hodges Reservoir should not exceed 295 feet, which is 20 feet below spillway elevation, Ysea said. This requires periodic water releases from Hodges Reservoir.

‘Baking Skills’ Used for Repair at Lake Hodges Pumped Storage Facility

You might not think ‘baking skills’ would come in handy to fix a recent problem at the Lake Hodges Hydroelectric and Pump Station Facility. But those skills, along with initiative and ingenuity, were demonstrated by San Diego County Water Authority staff as part of the creative and complex repair.

The facility connects the City of San Diego’s Hodges Reservoir with the Water Authority’s Olivenhain Reservoir. The connection provides the ability to store up to 20,000 acre-feet of water at Hodges for emergency use.

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‘Baking Skills’ Used for Repair at Lake Hodges Pumped Storage Facility

You might not think ‘baking skills’ would come in handy to fix a recent problem at the Lake Hodges Hydroelectric and Pump Station Facility. But those skills, along with initiative and ingenuity, were demonstrated by San Diego County Water Authority staff as part of the creative and complex repair.

The facility connects the City of San Diego’s Hodges Reservoir with the Water Authority’s Olivenhain Reservoir. The connection provides the ability to store up to 20,000 acre-feet of water at Hodges for emergency use.

The Lake Hodges Hydroelectric and Pump Station Facility moves water between Olivenhain and Hodges, and is able to generate up to 40 megawatts of energy on demand, helping to manage electrical demands throughout the County. It also generates revenue and helps offset energy costs.

Ground fault alarm alerts staff

A ground fault alarm on August 25, 2019 alerted staff to a potential problem with Unit 2, one of the facility’s two 20-MW pump-turbine units. A series of tests and inspections by staff with the Water Authority’s Rotating Equipment team discovered the insulation on the copper bus bars of the generator’s rotor were worn and damaged. The bus bars are part of a system that provides DC power to the 12 electromagnets which surround the outer surface of the pump turbine unit’s rotor.

The rotors are designed to spin at 600 revolutions per minute and it’s the rotor’s electromagnets acting upon the stators windings that generates power. The electromagnets are connected together by copper bus bars located on top of the rotor and the bus bars are secured to the rotor by clamping plates and rim studs. The bus bars are insulated to ensure the copper does not touch any other metal surface and cause an inadvertent ground fault.

“Although a single ground fault may not damage the pump-turbine unit, it may prevent it from starting, if two ground faults were to occur, significant damage to the pump-turbine unit would occur and would also be an extreme danger to anyone within the facility,” said Jim Fisher, Water Authority director of operations and maintenance.

Creative solutions and ingenuity save time, money

Among various factors, the primary cause of the insulation failure was determined to be improper wrapping and curing of the insulation during initial installation.

Water Authority staff developed solutions and also took on the repair tasks in September. By doing the work in-house, the Water Authority avoided a more extensive outage due to long lead times required by contractors and vendors to perform the same work, saving time and money.

“Staff did an excellent job maintaining the operation of Unit 1 while making the repairs to Unit 2,” said Fisher, “which allowed the Water Authority to avoid a total shutdown and loss of all revenue during this period.”

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Initiative and ingenuity by San Diego County Water Authority staff led to a creative repair solution at the Lake Hodges Hydroelectric and Pump Station Facility. Photo: San Diego County Water Authority

‘Baking skills’ come in handy to create new bus bars

New copper bus bars were fabricated, and each had to be precisely wrapped by 5 different types of insulating tape materials. This wrapping process alone took approximately 8 hours per bus bar. The bus bars were then baked for ten hours within newly designed and fabricated aluminum molds to ensure proper pressure was applied to the insulation layers during the baking and curing process.

Staff efficiently re-purposed and utilized an oven that had been retained from the San Vicente Dam Raise Project to perform the baking. The Rotating Equipment team’s efforts produced excellent quality results which would have been difficult even for a vendor to meet. The newly insulated bus bars were re-installed, and the unit has been operating safely and without issues.

The initiative, ingenuity, and highly technical skills and knowledge of our staff were once again on display throughout the repairs,” said Fisher. “Their dedication, talents and outstanding efforts continue to ensure the Facility’s efficient and safe operation.”

Unit #2 was tested and placed back into service on November 17, 2019.

Along with the bus bar insulation and curing process repair, staff also performed many other highly technical, innovative and precise processes to complete this repair work.

City of San Diego’s Hodges Reservoir Reopens Feb. 5 for Recreation

The city of San Diego’s Hodges Reservoir will officially reopen to the public three days a week beginning on Wednesday, Feb. 5, allowing access for a variety of activities, including boating, fishing, hiking and picnicking. Hodges is normally closed November through January.

Hodges will be open Wednesdays, Saturdays, and Sundays from sunrise to sunset. It will also be open on Memorial Day, Independence Day and Labor Day holidays.

New Oxygenation System to Improve Water Quality at San Diego Reservoir

The City of San Diego’s Public Utilities Department last week took a major step toward completing an innovative project to improve water quality in Lake Hodges. A newly installed oxygenation system, designed by city engineers, will introduce highly oxygenated water to the bottom of the reservoir to reduce the accumulation of excess nutrients and harmful algae growth.

Heavy Rains May Prompt San Diego to Lower Water Level in Lake Hodges

San Diego officials announced Friday that they may release water from the Lake Hodges Reservoir near Rancho Bernardo this winter if rainfall pushes the water level above where it is permitted under state regulations.

The California Division of Safety of Dams has determined that the water level in the reservoir should no longer go above 295 feet, which is 20 feet below the spillway elevation — a formal term for the top of the dam.