Waste not, want not: California’s Drought – Part 1

March 15, 2015

Few people in California realize that the vast majority of rain and snow that falls in California ends up going into the Pacific Ocean unused by farmers, citizens, or industry. Over 21 million acre feet of fresh water in an average year flows down the Sacramento River through the Sacramento Delta emptying into the Pacific Ocean.  21 million acre feet (AF) is a staggering amount of water. An acre foot of water is one foot of water covering 1 acre. One acre foot equals 352,851 gallons. To put this quantity of water into perspective, the average person living in Los Angeles or San Francisco uses about 50 gallons of water per day. So 21,000,000 AF is 7.4 Trillion gallons of water per year or enough water for 406 million typical folks living in the urban areas of California or over 10 times the number of people currently living in California. We could all have swimming pools, wash our cars whenever we wanted, and take amazing high flow showers and still have water left over for more farms. Instead we suffer and worry. Remember this 7.4 trillion number excludes all current California farm irrigation. California doesn’t have a water problem even during times of drought. California has a water management problem.

The number one news story in California during 2014 was the drought. Californians are acutely aware of our perilous water problems, we see the fields lying fallow, orchards now just stumps, and the concerns of farmers who are pumping too much ground water. Despite all the hand wringing and hundreds of news story this water waste information is probably new to the average Californian. So the next time, you are being threatened with water usage fines, flushing smelly low flow toilets, and watching your lawn turn brown in the summer remember that 80% of California’s water is wasted by design. On the other hand, this information is not new to the generations of California engineers who designed the dams, canals, pumps, water tunnels, and reservoirs. California has enjoyed an uninterrupted supply of water due to the great work done by these engineers, construction workers, and political leaders for nearly 150 years. Some of the political leaders in particular were Gov. Brown (current Gov. Brown’s father), and Presidents John F Kennedy and Franklin D. Roosevelt. Despite all their efforts the single biggest waste of California water, though clearly identified by engineers, was never successfully addressed.

Here is an example of just how serious and ridiculous the problem is:  during the massive winter rain storm in November 2014 the Sacramento River was swollen with water, a few flood warnings were issued, but still the dams in Northern California were releasing over 4000 cubic feet of water per second into the Sacramento River! Please note, this is not because our water engineers are stupid. We released enough water from our dams in this single rain storm to provide water for both Los Angeles and San Francisco for many years. People driving by the massive Shasta Reservoir off of I-5 witness the dirt ring indicating just how much higher the reservoir could be and it is natural to worry about our water supply. However, most Californians don’t realize that the majority of the water in the Shasta and Oroville Reservoirs isn’t slated for domestic or farm use, it will be wasted … intentionally.

Here is the reason for our massive water waste – the majority of California’s fresh water is used for the single purpose of keeping salt water from the San Francisco Bay out of the Sacramento Delta. California uses more than 70% of all our fresh water budget to push salt water downstream in worst case conditions about 10 to 15 miles in support of a tiny percentage of California farms and few small communities near the outlet of the Delta. This is like trying to air condition a house in the middle of hot summer day with the windows wide open. Even crazier, this dumping of fresh water is today a higher volume during the majority of the year as compared to the days before farmers settled the Delta – there is no historical or environmental precedent for this wasting of water. Thomas Means, an engineer in the 1920’s, was hired to look at this problem and stated that it was not rational to expect California to waste the amount of water necessary to flush the Delta of salt water at all times for so little economic benefit especially during times of drought. Mr. Means was hired by those in the Delta, he was the pro-Delta guy. Mr. Means proposed a salt water intrusion barrier (close the window in our air conditioning analogy) to be used during times of drought and low river flow, thus providing fresh water to the Delta farms and local communities. Despite the salt water barriers numerous benefits and relatively low cost, the salt water intrusion barrier was never built because of objections in the local Delta communities. As a result, California continues to pours the vast majority of it’s water into the Pacific to support a tiny fraction of the California community.

The Delta is roughly a triangular region with Sacramento as the northern point, Tracy as the southern point, and Martinez as the western point. This author lives in the Delta. Before industrious white farmers arrived around 1850, the Delta was a near sea level brackish swamp with hundreds of channels used by a native tribe for fishing. Brackish means sometimes salty, sometimes fresh water. The Delta is quite unusual, because most Deltas ( Nile Delta, Mississippi Delta) begin from a single river and then spread out with numerous channels before emptying out into a large body of water. Our Delta is formed by two rivers, the Sacramento and San Joaquin. These rivers quickly fan out forming numerous channels and islands before being constricted again near Antioch. Our Delta appears inverted due to this local geography.

Living in the Delta region, it is easy to notice the numerous bumper stickers, signs, and events for “Restore the Delta”, “Save the Delta”, etc. Of course, it begs the question – Restore the Delta to what? In our short lifetimes, it is difficult to fully appreciate how the land changes around us so in order to understanding our changing landscape we turn to science. Numerous studies have shown that at the end of the last ice age sea levels were rising rapidly. The San Francisco Bay and the Central Valley of California were below sea level at this time. As the sea levels continued to rise salt water flowed into the San Francisco Bay and much of the Central Valley of California. The area of today’s Delta was decidedly covered entirely in salt water. However, as our earth continued to warm the glaciers in the Sierras melted. The melt water brought down vast quantities of sediment thus raising the elevation of the Central Valley and the Delta turning them into a grass land and fresh water swamp respectively. Around 2000 years ago, most of the significant Sierra glaciers had melted reducing the sediment flow while sea levels continued to rise as glaciers continued to retreat elsewhere in the Northern Hemisphere. Thus around the time of Christ, the Delta turned from a fresh water swamp to a brackish swamp and has remained so ever since.

Geological processes can be slowed by mankind, but they cannot be stopped. Going forward, the Delta, Suisan Bay, San Pablo Bay, and San Francisco Bay will eventually be dry land as sediment continues to flow down the Sierra mountains and sea-mud comprised local hills. The current rate of land formation is around 1 km per 100 years. However, the massive Northern California dams built between 1940 and 1970 are slowing this process as they trap an enormous amount of sediment that would have otherwise been deposited from the Delta to San Francisco Bay. For example, Lake Shasta is reported to be 10% full of sediment and at least three other Northern California dams are nearly non-functional for water storage or power generation due to massive sediment build up behind them. It is reasonable to predict that Stockton will not have access to ocean shipping a few hundred years from now. Without human intervention, the Delta is on it’s way towards looking like the rest of the Central Valley with a new Delta eventually forming near the Golden Gate Bridge.

Historically, the Delta would often flood with fresh water during the spring due to the snow melt water flowing down from the high Sierra Mountains, then return to salt water or brackish condition as the river flows slowed during the summer and fall. The early settlers built levees to control the spring floods by dredging the natural channels deeper. Making the natural channels deeper allowed salt water to intrude further into the Delta for two reasons: one, a deeper channel increased the channel capacity allowing more salt water to flow upstream during high tides (this is equivalent to making a the window bigger in our air conditioning analogy); two, salt water is heavier than fresh water so once up stream a lot more fresh water is required to flush out the salt water located on the bottom portion of the channel. The salt water only moderately mixes with the fresh water above it due to the density difference. Even so, the climate and soil proved to be highly productive encouraging further farm development. The dredging and farm expansion continued until 1920 when nearly every part of the Delta has been turned into productive farm land. Local towns addressed the brackish water problem by building reservoirs to capture the spring runoff and store if for the late summer and fall. Then came two critical years of drought in 1918 and 1919.

During these two drought years there was so little river flow that the towns of Pittsburg (formerly “New York of the Pacific”), and Antioch, the nearby  farms, along with fresh water dependent industries further downstream grew concerned that their would be no fresh water available during any part of the year. Ignoring their own dredge created salt water intrusion issue, the local Delta folks blamed the upstream rice growers for taking an increasing amount of fresh water for irrigation leaving nothing but saltwater downstream. They sued the rice framers in 1920. The local authorities made the claim that fresh water was always available at Antioch except for a few days a year. This exaggeration will be debunked in Part II.

When the amazing California Aqueduct and Delta-Mendota Canal were built to provide water to Southern California communities and farms, they tapped into the southern Delta capturing a portion of the spring runoff from the Sacramento and San Joaquin Rivers. While these projects reduced by a tiny fraction the amount of water California wastes, they also set up a perverse situation. In order for a gallon of water to be shipped to S. California, about up to 4 gallons of water must be wasted. Once again, there are very good engineering reasons for this. The Delta is not a real reservoir, it is not a deep body of water, it is more like a massive puddle. Thus if a straw is stuck in one side of the puddle and a suction pump applied, water from all directions of the puddle will flow towards the suction pump including salt water from San Francisco Bay. Thus up to 4 gallons of water must be pouring into the Delta from the north via the Sacramento River, if 1 gallon of water is sucked out from the south to avoid salt water contamination coming from the west. In other words, in order for Los Angeles to get a gallon of water, up to 4 gallons must be wasted in Northern California. This is how the first part of our north-south water system was designed. However, water engineers also assumed that our water system would be further developed incorporating one or more of the accepted engineering solutions addressing the Delta salinity issue. However, due to modern political pressure and pseudo-science the water system is not finished and the colossal water waste continues over the objections of generations of engineers.

Part 2 – Was Delta Water always Fresh?

 

 

 

 

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