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Location, location, location: It’s driving four new dam projects on valley’s edge
Dennis Wyatt 2022
Dennis Wyatt

paradox / par a doks/ noun   Something (such as a situation) that is made up of two opposite things and that seems impossible but is actually true or possible


The Golden State is in the midst of recovering from a flood emergency while in the middle of a drought emergency.

It’s the definition of a true paradox, California-style.

We act surprised. We pin it on manmade climate change, the boogeyman — or is that boogeyperson — of the 21st century.

And we do so at our collective risk.

For at least 1,200 years the area we call the Southwestern United States, which includes present-day California, has cycled through droughts and flooding on such a scale that the adjective “mega” is aptly tacked on.

That is not a conclusion reached by so-called “climate deniers” of whom many contend weather patterns happening today aren’t necessarily out of the norm for earth.

Instead, it is the conclusion of scientists versed in dendrochronology — the study of tree rings — with a boost from carbon dating.

The 20-plus days of rain in the past month is not unprecedented in its length or its precipitation.

It rained almost every day for nearly a five-week period  between Dec. 9, 1861 and Jan. 17, 1862. This was before the widespread use of carbon-based fuels which, based on the assumption of those who believe the weather we are experiencing today is 100 percent the direct result of man, is a blasphemous statement.

Nor was the Great Central Valley Flood of 1861-1862 a fluke.

Indigenous Americans knew the  Sacramento Valley and the San Joaquin Valley could become an inland sea when the rains came. Their storytellers described water filling the valley from the Coastal Range to the Sierra.

This is not a denial of climate change, but rather an affirmation.

Yes, greenhouse gas contributes but the driving force is — and has always been — nature.

The forces that are constantly sculpturing the planet’s mountains, valleys, deserts, plains, and oceans need to carry the heaviest weight in decisions we make to basically make sure the California civilization — and that of the rest of the Southwest — doesn’t vanish as the Anasazi civilization did.

It was a highly advanced society located in the high desert area where New Mexico, Colorado, Arizona and Utah are today that collapsed due to climate change — a mega-drought that started in 1270.

What happened in the past as climate change shaped California — one of the relatively youngest parts of the planet’s crust geologically speaking — is best dealt with by addressing the biggest factor.

It starts with long-range solutions to address water needs — and water control — to deal with what nature does and doesn’t send our way.

Virtually every model being offered up for climate change impacts in California comes to the same conclusion.

There are years ahead of us with below normal precipitation, drought. And that includes periods that could go dozens of years with little relief.

There are also periods ahead of us just like we have just experienced.

The go-to solution is creating more storage.

And while recharging aquifers with recycled water or and storm water is a must, it is clear when we get roughly 20 days of rain in a month like we did that there is way too much for the ground to absorb.

That means besides judicious use of water we need above ground storage.

But there is a wrinkle.

The climate models show that when we do get precipitation, the pattern will be shifting even in “average” weather years.

That shift means less snow in the mountains and a higher snow level. It also means more rain will fall in the foothills and the valley.

Practically speaking, an average winter of precipitation could one day soon be a miserable year for many Sierra ski resorts.

This is why the real estate maxim “location, location, location” needs to be taken seriously.

Simply creating more storage in the higher elevations whether it is adding to Shasta Dam, trying to resurrect the idea of the Auburn Dam from the dead, or even building more small reservoirs above 2,000 feet is not going to work.

The Stanislaus River illustrates this point perfectly. Based on the pending State Water Quality Control Plan and the 40 percent unimpaired flow requirement that will help boost the combined numbers of Chinook salmon on the Stanislaus, Merced and Tuolumne rivers by 1,500 annually, New Melones Reservoir would have fallen below 250,000 acre feet in 20 out of the past 98 years.

Toss in more severe drought years punctured with years of excessive precipitation concentrated at the lower elevations and that modeling becomes wishful thinking.

Aquifer recharging aside that is an absolute must, the other critical need is off-stream reservoirs in the lower elevations where they can have excess storm-runoff as well as excess snowmelt diverted into them.
The 2,041,000 million acre foot San Luis Reservoir 12 miles west of Los Banos is the largest off-stream reservoir in the United States and the fifth largest reservoir per se in California.

The federal government is currently funding an earthquake retrofit project at the Central Valley Project reservoir.

At the same time the Bureau of Reclamation is working with the San Luis & Delta-Mendota Water Authority to investigate raising the dam 10 feet to create an additional 130,000 acre foot of storage

That new storage would meet existing contractual obligations and not serve any new demands.

California is in the process of building an off-stream reservoir in the Sacramento Valley known as Sites. Construction, according to the Department of Water Resources, is targeted to start in mid-2024, with final design completed in 2025, and operations expected to begin by 2030.

It is in the Coastal Range foothills 10 miles west of Maxwell.

The proposed 1.5 million acre foot Sites Reservoir will capture and store stormwater flows from the Sacramento River – after all other water rights and regulatory requirements are met – for release in dry and critical years for environmental use and for California communities, farms, and businesses.

When operated in coordination with other Northern California reservoirs such as Shasta, Oroville and Folsom, which function as the backbone to both the Central Valley Project and the State Water Project, Sites Reservoir will greatly increase flexibility, reliability and resiliency of statewide water supplies in drier periods.

To the northwest of Tracy in the rolling hills of the Diablo Range, the Contra Costa Water District is in the process of working toward groundbreaking of an expansion of Los Vaqueros reservoir from 160,000 to 275,000 acre feet.

West of Patterson, the vetting of the environmental review document is underway for the proposed Del Puerto Canyon Reservoir that would create 82,000 acre feet of storage.

While that represents four reservoir projects — either for new or expanded storage — in the planning process, is clearly not enough.

All four reservoirs are located in the lower foothills of the coastal range.

Off-stream reservoirs, such as San Luis, are often filled with water pumped uphill. San Luis taps into water exported from the Delta via the Delta Mendota Canal and California Aqueduct.

Right or wrong, the California Environmental Quality Act makes building new reservoirs or increasing the heights of existing dams an uphill battle.

But if we want to guard against future droughts we need to get those four projects built as well as others that make sense.

And while raising Shasta Dam might be heralded as getting more bang for the buck  to add 634,000 acre additional feet of storage to the reservoir that is now rated at 4,552,000 acre feet, based on shifting precipitation patterns it may not be most lucrative strategy as the climate changes.