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Literary Corner

Cachuma Lake: Our primary water source | Judith Dale

  • Updated

Neighbors and I were discussing the recent rains and the resulting rise in the water level at Cachuma Lake. Our new neighbor, who just moved here from out of state, asked, "Where is Cachuma Lake, and why is the water level important?"

She had no idea that Cachuma Lake, created by Bradbury Dam, controlled the Santa Ynez River and, therefore, the water supply for the Santa Ynez and Lompoc valleys. 

In addition, Cachuma Lake is a primary water source for the South Coast communities of Goleta, Santa Barbara, Montecito, Summerland and Carpinteria.

Water from Cachuma flows through the 6-mile Tecolote Tunnel under the Santa Ynez Mountains to the South Coast Conduit. The conduit then delivers water to various reservoirs that service the cities and the 38,000 acres of outlying agricultural lands in southern Santa Barbara County. NOTE: Two dams built in the 1920s on the upper Santa Ynez River — Juncal, which services Montecito, and Gibraltar, which services Santa Barbara — also provide water to the South Coast, but today Cachuma is by far the primary source.

History of Cachuma Dam

The Cachuma project was one of three large-scale federal water projects in our area. The other two were in Santa Maria and Ventura. These three projects were designed to capture the winter rain runoff that would otherwise flow out to the ocean.

The creation of Cachuma Lake took almost 20 years.

In 1938, the Santa Barbara County Board of Supervisors commissioned a report to study the utilization of water resources. The results called for an additional dam to be built on the Santa Ynez River to service the South Coast. The report stated that "the future of Santa Barbara County depends upon the prompt execution" of the proposal.

011722 Lake Cachuma graph

The Santa Barbara County Cachuma Reservoir graph shows the water storage levels from 1985 to 2022.

It is interesting to note that nothing was mentioned about ensuring the water supply to the down-river communities of Santa Ynez and Lompoc valleys would be protected in the original proposal. It took a lawsuit by Gin Chow, a farmer in Lompoc, to ensure the water tables down-river would be maintained.

Following the 1938 report, almost 10 years of political battles ensued. Two influential local figures, Thomas Storke, the Santa Barbara News-Press publisher, and County Supervisor Charles Leo Preisker, joined forces to push for the new dam.

The South Coast’s increasingly serious water problem was a significant factor. By the fall of 1947, Southern California was in the grip of a severe drought. Estimates held that if there was no significant rainfall soon, Gibraltar would dry up by April 1948.

The Cachuma site for a new dam was formally approved in December 1947.

There was still significant opposition to the Cachuma site, led by Lewis Welch, San Fernando Rey Ranch owner in the Santa Ynez Valley. A good part of Welch's land would be inundated if the water project proceeded. Meanwhile, negotiations continued with the federal government to secure the necessary construction funds for a dam. Storke once again entered the fray, pulling every political string he could. He was joined by county supervisors T.A. Twitchell and Clifford Bradbury, who was later honored by having the dam named for him.

An election was held in November 1949 to put the stamp of approval on the Cachuma project. It was the last stand for Welch and the dam’s opponents. Storke continued his resistance, while Santa Barbara’s mayor and other influential figures spoke out as proponents for the project. The final tally showed over 75% of the voters were in favor.

Construction of Cachuma Dam began in 1950 and was completed in 1953. The dam is 279 feet high (206 feet above the streambed) and 2,850 feet wide. It is an earth-fill structure containing over 7 million cubic yards of material. The spillway section is concrete lined with four 50-by-30-foot radial gates that can release 161,000 cubic feet of water per second. The final price tag on the project was $43 million, or $420 million in today’s dollars.

The dam is designed to spill over the top. The lake filled, and water spilled for the first time on April 12, 1958. An article in the paper stated, “It is the most important event in the modern history of Santa Barbara.” It would be difficult to disagree, because the building of the dam allowed the South Coast to both support the postwar housing and commercial boom and keep its irrigated agricultural land.

In 1971, Cachuma Dam was renamed Bradbury Dam to honor C.W. Bradbury, a county supervisor and local water supply proponent.

Cachuma Lake

The dam created a beautiful lake that covers 3250 acres and, when full, has a 42-mile shoreline and a depth of 138 feet. The maximum water storage capacity is 205,000 acre-feet. An acre-foot is the amount of water covering one acre to a depth of one foot. An acre-foot equals 326,000 gallons of water, or 43,560 cubic feet of water.

An acre-foot of water can support 10 people for a year, as it is estimated each person uses an average of 90 gallons of water a day for drinking, cooking, bathing, cleaning, etc.

The depth of Cachuma Lake can vary widely depending upon the amount of rainfall in the area. In October 2016, the lake was the lowest since its construction. The volume was only 14,057 acre-feet, approximately 7.3% of its capacity.

In January and February 2017, a series of rains raised the water level substantially. In one day, Feb. 17, 2017, the lake rose an astounding 25 feet during a storm. By the end of that year, the lake was 44.5% full, with a total volume of 85,979 acre-feet.

The lake's water level again declined during the 2017-18 water year and was less than one-third of its capacity. However, by late March 2019, above-normal rain had restored it to 78% capacity.

The late rains of 2020 kept the lake at 77% capacity. However, with 2021 being a dry year, only 7.31 inches of rain fell. In early December, the lake was down to 44.6% capacity.

As I write this article in early January 2022, the lake is at 48.3% capacity, almost a 4% increase due to the recent rains. However, we still need to conserve water as the lake is less than half capacity.

Before these recent storms, many wells in the Santa Ynez Valley were going dry. My family has three wells on the river — two are doing fine, but one is dry. Friends who own farms along Santa Rosa Road told me their wells are dry.

This is an ongoing battle for water between the downstream water users (Santa Ynez and Lompoc valleys) and the needs of the South Coast. How much water should be released for down-river wells and how much water should be allocated to the South Coast? The down-river wells not only serve the farmers between the dam and the mouth of the river west of Lompoc but the communities of Santa Ynez, Solvang, Buellton and Lompoc, all of which depend upon water from wells on the river.

Once all this was explained to our new neighbor, she understood the importance of the lake level. It is the primary factor for determining the prosperity of south and central Santa Barbara County regions. That is why often the topic of conversation is, "How full is Cachuma Lake?"

Cachuma Lake not only stores water but provides excellent opportunities for recreation such as boating, fishing, hiking, observing nature, etc. I will save that topic for a future article.

What a jewel Bradbury Dam and the resulting Cachuma Lake is for our area. I cannot even imagine how different life here would be without them.

Whistleblower lawsuit blasts Santa Ynez River district

Cachuma Lake water released from beneath Bradbury Dam flows down the Santa Ynez River, at left, in April 2019. 

28 stories about Santa Barbara County's history, landscape and traditions | Judith Dale

Get better acquainted with our beautiful slice of California with this collection of columns from Judith Dale highlighting the culture, geography and history of the Central Coast.

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At one time, Hollister and his partners, the Dibblee Brothers, owned all the land between Refugio Beach and Point Conception. They owned all the land grants around Point Concepcion, the Ortega family’s Refugio Grant, the La Purisima Mission lands and the San Julian Ranch.

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We often overlook and take for granted the importance of the river to our past development and more importantly to our future development and quality of life.

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The area around Guadalupe has evolved through many stages — from Chumash villages, to Spanish rule under Mission La Purisima, to a Mexican land grant, an immigrant farming community, a railroad town, and a modern agricultural city.

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We have the perfect setting for fires: thousands of acres of wilderness with rugged terrain and few roads; rainy winter weather that allows grass and brush to grow, followed by months of hot, dry weather; prevailing winds as well as sundowner winds; and people, who are the cause of most fires.

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Judith Dale looks back to 1920, offering a timeline of progress the U.S. has made over the last 100 years. In most areas such as life expectancy, industry, technology, and position in the world, the U.S. has come a long way. However, many of the social/cultural challenges the country faced in the 1920s, are still with us today.

Former mayor of Buellton, Judith Dale built her career in education and continues to serve the local community as Santa Barbara County 3rd District representative to the Library Advisory Board and board member of the Santa Ynez Valley Cottage Hospital Foundation. She can be reached at


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