The present four-year California drought is not novel — even if President Barack Obama and California Gov. Jerry Brown have blamed it on man-made climate change.

According to the National Oceanic and Atmospheric Administration, California droughts are both age-old and common. Predictable California dry spells — like those of 1929-34, 1976-77 and 1987-92 — more likely result from poorly understood but temporary changes in atmospheric pressures and ocean temperatures.

What is new is that the state has never had 40 million residents during a drought — well over 10 million more than during the last dry spell in the early 1990s. Much of the growth is due to massive and recent immigration.

A record one in four current Californians was not born in the United States, according to the nonpartisan Public Policy Institute of California. Whatever one’s view on immigration, it is ironic to encourage millions of newcomers to settle in the state without first making commensurately liberal investments for them in water supplies and infrastructure.

Sharp rises in population still would not have mattered much had state authorities just followed their forbearers’ advice to continually increase water storage.

Environmentalists counter that existing dams and reservoirs have already tapped out the state’s potential to transfer water from the wet areas, where 75 percent of the snow and rain fall, to the dry regions, where 75 percent of the population prefers to reside.

But that analysis is incomplete.

After the initial phases of the federal Central Valley Project and state California Water Project were largely finished — and flooding was no longer considered a dire threat in Northern California — environmentalists in the last 40 years canceled most of the major second- and third-stage storage projects. To take a few examples, they stopped the raising of Shasta Dam, the construction of the Peripheral Canal, and gargantuan projects such as the Ah Pah and Dos Rios reservoirs.

Those were certainly massive, disruptive and controversial projects with plenty of downsides — and once considered unnecessary in an earlier, much smaller California. But no one denies now that they would have added millions of acre-feet of water for 40 million people.

Lower foothill dams such as the proposed Sites, Los Banos and Temperance Flat dams in wet years would have banked millions of acre-feet as insurance for dry years. All such reservoirs were also canceled.

Yet a single 1 million acre-foot reservoir can usually be built as cheaply as a desalinization plant. It requires a fraction of desalinization’s daily energy use, leaves a much smaller carbon footprint, and provides almost 20 times as much as water. California could have built perhaps 40-50 such subsidiary reservoirs for the projected $68 billion cost of the proposed high-speed rail project.

California’s dams and reservoirs were originally intended to meet four objectives: flood control, agricultural irrigation, recreation and hydroelectric generation. The inevitable results of sustaining a large population and vibrant economy were dry summer rivers in the lowlands and far less water reaching the San Francisco Bay and delta regions.

Yet state planners once accepted those unfortunate tradeoffs. They would never have envisioned in a state of 40 million using the reservoirs in a drought to release water year-round for environmental objectives such as aiding the delta smelt or reintroducing salmon in the San Joaquin River watershed.

No one knows the exact figures on how many million acre-feet of water have been sent to the ocean since the beginning of the drought. Most agree that several million acre-feet slated for households or farming went out to sea.

There is more irony in opposing the construction of man-made and unnatural reservoirs, only to assume that such existing storage water should be tapped to ensure constant, year-round river flows. Before the age of reservoir construction, when rivers sometimes naturally dried up, such an environmental luxury may have impossible during dry years.

Agriculture is blamed for supposedly using 80 percent of California’s storage water and providing less than 5 percent of the state’s GDP in return. But farming actually uses only about 40 percent of the state’s currently available water. Agriculture’s contribution to the state’s GDP cannot be calibrated just by the sale value of its crops, but more accurately by thousands of subsidiary and spin-off industries such as fuel, machinery, food markets and restaurants that depend on the state’s safe, reliable and relatively inexpensive food.

The recent rise of Silicon Valley has brought in more billions of dollars in revenue than century-old farming, but so far, no one has discovered how to eat a Facebook page or drink a Google search.

Stanford University, Hollywood and Silicon Valley do not sit on natural aquifers sufficient to support surrounding populations. Only privileged water claims on transfers from Yosemite National Park, the Central Sierra Nevada Mountains, Northern California or the Colorado River allow these near-desert areas along the coastal corridor to support some 20 million residents. Much of their imported water is used only once, not recycled and sent out to sea.

A final irony is that the beneficiaries of these man-made canals and dams neither allowed more water storage for others nor are willing to divert their own privileged water transfers to facilitate their own dreams of fish restoration. Nature may soon get back to normal — but will California?

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