Gibraltar Reservoir Turns 100

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Gibraltar Reservoir Turns 100
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Source: City of Santa Barbara

The City of Santa Barbara’s Gibraltar Reservoir is 100 years old! Construction of Gibraltar was completed on January 26, 1920. The reservoir is located nine miles north of the City, along the Santa Ynez River. Gibraltar has served an important role in providing the City with affordable drinking water for the past ten decades. 

In 1903, the City employed J.B. Lippincott of the U.S. Geological Survey to examine Santa Barbara’s growing water supply problem. A dam in the drainage basin of the Santa Ynez River was one of Lippincott’s recommendations, and a potential site was named. A month after submitting his report, Lippincott, searching for a lost mule, came upon the Gibraltar site, which became his ultimate recommendation.  The construction bid for Gibraltar was $342,981, which was funded by bonds. Bent Construction began the project in May 1918 and was completed on January 26, 1920.

Gibraltar Dam impounds Santa Ynez River water in Gibraltar Reservoir which conveys water through 3.7-mile-long Mission Tunnel to the City. Mission Tunnel was completed in 1912, eight years prior to the construction of Gibraltar Dam, “If they couldn’t build a tunnel through the Santa Ynez Mountains, the dam would not have done us any good,” said Joshua Haggmark, City Water Resources Manager. At the time it was built, Mission Tunnel was the longest irrigation tunnel in the world, passing under La Cumbre Peak the tunnel is nearly 3,000 feet underground. Water from Gibraltar flows through Mission Tunnel to Lauro Reservoir, and on to Cater Water Treatment Plant (Cater) entirely under gravity. In fact, the water dropping down from Gibraltar is capable of powering a small hydroelectric plant located at Lauro Reservoir, and in a good year it nearly covers all the electrical demand at Cater. The engineers for the Gibraltar - Mission Tunnel system designed a truly green energy project with a minimal carbon footprint. When full, Gibraltar has the capability to release water during torrential rain a rate of 40 million gallons per minute flowing downstream into Cachuma Reservoir.

Prior to constructing Gibraltar, Santa Barbara relied entirely upon groundwater sources. Gibraltar, along with Mission Tunnel, introduced a much needed water supply that enabled Santa Barbara to grow and develop into a City. “To be able to tap into this pristine watershed was huge,” said Joshua Haggmark. “Gibraltar was the first step in diversifying the City’s water supply portfolio, and has continued to provide benefits for the past hundred years.”

Gibraltar is an important component of the City’s water portfolio, which includes Lake Cachuma, recycled water, imported state water, desalinated water, and groundwater. All of the City’s water supplies, along with the community’s extraordinary water conservation efforts, were essential with ensuring the City had sufficient drinking water supplies throughout the recent drought. 

For more information on Gibraltar visit:

Happy 100th Birthday, Gibraltar!

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biguglystick Jan 29, 2020 02:45 PM
Gibraltar Reservoir Turns 100

At first glance I thought this article was saying the dam was at 100% capacity. Lots of water would be a good thing... but we do need infastructure studies and improvements. A flood from this dam would be catastrophic in heavy rains.

Chip of SB Jan 29, 2020 01:12 PM
Gibraltar Reservoir Turns 100

Here is a study by the Bureau of Reclamation on the Cachuma project from 1995. This study describes the history of water usage in this area which led to the need for Cachuma, including some discussion of Gibraltar dam. Gibraltar was only designed to meet the needs of a city of 20,000, and the population was already at that level by the time the project was finished. In addition, Gibraltar had silting issues from the very beginning. By 1947, it's original capacity of 14,500 acre feet had already been reduced to just 7,600. Cachuma by contrast has a capacity of nearly 200,000 acre feet.

a-1580322056 Jan 29, 2020 10:20 AM
Gibraltar Reservoir Turns 100

Our most recent 1950 CA Master Plan for infrastructure is for 30M residents and we are now at 40M. Now is the time for locals to demand infrastructure improvements using our tax money for our collective good rather than for more govt worker salaries, lifetime increased pensions and benefits, shorter worker days, and waste. Wake up BoS and City Council Reps throughout SB County. Serve your public rather than only your support base.

RHS Jan 29, 2020 10:06 AM
Gibraltar Reservoir Turns 100

Gee, people found several versions of negative to post on this innocent story. If the dam has served for a century it has almost certainly been a success. Let's note that and move on to a different story if you want to discuss the always present "water crisis" in our area.

SBWoman Jan 29, 2020 10:16 AM
Gibraltar Reservoir Turns 100

Old, out-dated infrastructure is a local, statewide and national crisis. With $1T in national debt, and a reported CA statewide “surplus”, let’s improve and expand our CA infrastructure systems or immediately lower taxes.

a-1580243768 Jan 28, 2020 12:36 PM
Gibraltar Reservoir Turns 100

But tell us, after numerous fires in the area, how much capacity does Gibraltar have with all the silt and debris from the burned areas being collected? Is there concern for the water supply or capacity?

a-1580249703 Jan 28, 2020 02:15 PM
Gibraltar Reservoir Turns 100

It spills after a light mist or heavy fog, probably isn't doing much good. It's the new Matilija Dam.

a-1580244531 Jan 28, 2020 12:48 PM
Gibraltar Reservoir Turns 100

I'll bet the average depth is around four feet due to the years' worth of silt. Does this serve any purpose anymore?

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