Tag Archive for: Temperance Flat Reservoir

How Much Water Will $30 Billion Buy?

/by

So far this year I had the privilege of attending two water oriented events. The first, in February, was at the annual CalDesal conference in Sacramento. The second, in March, was at the Kern County Water Summit in Bakersfield. I sensed there is a growing recognition among the participants in both of these events that not only is California’s state water policy fundamentally broken, because it still prioritizes rationing instead of more projects to increase supply, but also that there is more potential today than ever for regional interests to work together to demand a new approach.

Specifically, there is potential for water agencies and water users in California’s rural, agricultural San Joaquin Valley, to stand alongside water agencies and water users in Southern California’s megacities to promote a shared list of water supply projects that will eliminate water scarcity in the state forever. An incentive for this unity, and its urgency, may be found in what is about to be the greatest waste of money in California water history, the construction of the Delta Tunnel. A realistic, if not wildly optimistic cost estimate for that megaproject is $30 billion. That money could be used instead to help fund massive regional water projects. Split it 50/50: $15 billion for the farms, and $15 billion for the cities.

The Delta Tunnel, according to its own proponents, is only projected to deliver 500,000 acre feet of water per year to Southern California. Moreover, that is a gross number, since it is likely that use of the existing Delta pumps will be further restricted once water starts going through the tunnel. While the official cost estimate for the tunnel is $16 billion, California’s High Speed Rail project ought to provide a cautionary reality check. Does anyone sincerely believe it’s going to be possible to construct a tunnel 45 miles long with a 36 foot interior diameter, underneath one of the biggest estuaries in the world, for less than $30 billion?

Compared to other water supply project options, the Delta Tunnel does not make financial sense. Spending $30 billion to build something that will move 500,000 acre feet of water per year equates to $60,000 of capital cost per acre foot of annual yield. This is a terrible ratio.

For comparison, consider the proposed Temperance Flat Reservoir, for which the highest construction costs estimates came in at $3.5 billion. This reservoir would hold 1.3 million acre feet, and yet its detractors claimed its “yield” would only be 70,000 acre feet per year. Estimates vary, but even if that were true, at $50,000 in capital cost per acre foot of annual yield, it still beats the Delta Tunnel. And it would generate hydroelectric power. More recent evidence suggests that these biased estimates of its probable yield were low. Temperance Flat would have been full last year, and again this year.

In any case, Temperance Flat is one of the more expensive examples of surface storage options, yet it is clearly more cost effective than the Delta Tunnel. Consider the proposed Shasta Dam raise, for which engineering studies are already complete. Raising the height of the dam a mere 18 feet would increase storage in that vast lake by over 600,000 acre feet. And it, too, could have been filled to capacity this year, and last year.

Raising the height of the Shasta Dam attracts the same united chorus of opposition as Temperance Flat, but it makes so much sense that it continues to come up for discussion. A 2012 expert study claimed “dry year deliveries” from Lake Shasta would only increase by 76,000 acre feet. That’s not the average, of course. That’s worst case. But at an estimated cost of $1.8 billion (2024 dollars), that still equates to slightly less than $24,000 of capital cost per acre foot of annual yield, almost three times more cost-effective than the Delta Tunnel.

Other surface storage projects fall somewhere in between these estimates. All of them are better returns on investment compared to the Delta Tunnel. So what about desalination?

It is likely that if desalination plants were constructed at a larger scale, starting for example at 100,000 acre feet of annual capacity which is roughly twice the size of California’s existing plant in Carlsbad, the capital cost per acre foot of annual yield would be less. But as it is, referencing the inflation adjusted actual cost to build Carlsbad, and the more recent cost projections for the proposed plant in Huntington Beach, ocean desalination costs around $27,000 of capital cost per acre foot of annual yield.

The point here isn’t to proclaim desalination as a more cost-effective choice than surface storage. It probably isn’t on average. But it is a reliable water supply that is competitive with surface storage in dry years. More to the point is the fact that desalination, combined with upgraded wastewater treatment and urban runoff harvesting, all have the potential to significantly reduce the need for California’s big coastal cities to import water from the Central Valley. A $15 billion dollar investment in desalination would yield 550,000 acre feet per year, at a capital cost to annual yield ratio that is at least twice as favorable as that of the proposed Delta Tunnel. Putting that money into wastewater recycling instead would yield a comparable return. There is no serious water supply project option available to Californians that does not beat the Delta Tunnel in terms of return on investment.

Bear in mind the energy cost to pump water through seven pumping stations from the proposed tunnel entrance through southbound aqueducts and into Los Angeles is about 400 constant megawatts to move 1.0 million acre feet of water per year. That is almost exactly how much energy is required to desalinate an equivalent amount of salt water. Transporting fresh water over 500 miles, lifting it (cumulatively) over 2,000 feet, takes just as much energy per unit as ocean desalination. Just leave Diablo Canyon open. It generates five times that much in baseload electric power.

What proponents of desalination have to resist is the temptation to disparage surface storage options on environmental grounds while defending desalination against environmentalist objections. Ditto for the proponents of surface storage. They have to stop disparaging desalination while defending surface storage. Unite. Both solutions are necessary and feasible. The reasons environmentalists have been able to prevent major water supply infrastructure is largely due to a lack of sustained unanimity among proponents of infrastructure. At the heart of that needless schism is the mistaken idea that farm interests and urban interests are in inherent conflict.

Surface storage and desalination aren’t the only answers. Maybe there are better options. The San Joaquin Valley water agencies may be able instead to build fish friendly delta diversion filtration beds that would benignly transfer millions of acre feet per year of potential floodwaters into capacious quick-fill underground storage. Urban water districts may optimize stormwater harvesting in order to collect millions of acre feet more cost-effectively than desalination. What is certain is that conservation efforts have reached the point of diminishing returns. To achieve resiliency, or even abundance, we must agree to build ways to produce more water. Also certain? The Delta Tunnel is the worst option.

There’s $30 billion dollars up for grabs. Working together, urban and agricultural interests may be able to prevent it from being wasted. There’s still time. But they will have to agree on a list of projects that splits the money, and then they have to support each other’s proposals.

This article originally appeared in the California Globe.

Dams and Desalination – California Needs Both

/by

When Californians can take showers, without flow restrictors, for as long as they want, and when Californians can have lawns again instead of rocks and cacti in their front yards, water infrastructure in California will once again be adequate.

When California’s farmers can get enough water to grow food, instead of watching their suddenly useless holdings of dead orchards and parched furrows get sold for next to nothing to corporate speculators and subsidized solar farm developers, water infrastructure in California will once again be adequate.

One of the difficulties in forming a coalition powerful enough to stand up to the corporate environmentalist lobby in California is the perception, widely shared among the more activist farming lobby, that desalination is more expensive than dams.

That’s not true. It depends on the desalination, and even more so, it depends on the dam.

As a baseline, consider the cost of desalination in California’s lone large scale operating plant in Carlsbad north of San Diego. The total project costs for this plant, including the related pipes to convey the desalinated water to storage reservoirs, was just over $1.0 billion. At a capacity to produce 56,000 acre feet per year, the construction cost per acre foot of annual capacity comes in just over $17,000.

When it comes to the price of desalinated water, payments on the bond that financed the construction costs form the overwhelming share of the cost per acre foot.

For example, California’s second major desalination project, the proposed plant in Huntington Beach, will have a total project cost of $1.3 billion. Similar to Carlsbad, this plant will produce 50 million gallons of fresh water per day. A 20 year bond paying 7 percent will require annual payments of $122 million. That payment, applied to the hundred cubic foot increments, or CCF, that typically appear on a consumer’s water bill to measure their consumption, comes up to $5.03. By contrast, the cost per CCF for the desalination plant’s operating expenses is only $0.41, and the price per CCF for a desalination plant’s electricity consumption (at $0.10 per kilowatt-hour) is only $1.08. Initial construction costs, comprising 77 percent of the price of desalinated water, are the only reason desalination is considered expensive.

Compare this to the price of water from reservoirs, keeping in mind that paying off the construction costs for the dams are also the biggest variable in determining how much consumers have to pay for that water. With dams, unlike desalination plants, two factors come into play: the storage capacity, and the annual yield. With desalination plants the yield is up to the managers. Run the plant, out comes fresh water. With dams, how much water is released from the reservoir to downstream consumers in any given year depends on rainfall.

For this reason, the average annual yield of the reservoir is the most accurate way to measure its cost effectiveness. And this amount can vary widely. One of California’s biggest proposed new projects is the Sites Reservoir. It would be situated in a valley west of the Sacramento River, north of the Delta. As an off-stream reservoir, it would have water pumped into it when storm runoff is causing flooding. A twin to the already existing San Luis Reservoir, located west of the California Aqueduct south of the Delta, the Sites would have a capacity to store 2.0 million acre feet. But its yield is estimated at 500,000 acre feet per year.

In the case of the Sites Reservoir, this compares favorably to desalination. The Sites project is estimated to cost $5.0 billion, so the construction cost per acre foot of annual capacity comes in at $10,000, better than desalination at $17,000.

On the other hand, the case of the proposed Temperance Flat Reservoir is not so clear. The estimated cost for this dam is $2.6 billion and the planned storage capacity is 1.3 million acre feet. So far so good. But while estimates vary, the most optimistic projected average annual yield is around 100,000 acre feet per year. This equates to a construction cost of $26,000 per acre foot of annual capacity, considerably worse than desalination.

Does the fact that desalination yields a better return on construction costs than Temperance Flat mean that the Temperance Flat Reservoir project should be abandoned? Not necessarily. Back in 2017, during record rains, the San Joaquin River flooded, and that water – desperately needed by San Joaquin Valley farmers – could have still been in that reservoir and available for use today. The advantage of big surface storage reservoirs is not their return on capital investment, it’s that they can prevent flooding in wet years, and hold massive quantities of water in reserve for dry years.

Similarly, foes of desalination point to the more cost-effective Sites Reservoir proposal as evidence that desalination is too expensive. But the productivity of desalination is impervious to droughts; the water just keeps coming, year after year, no matter what. And the electricity required to run desalination, while significant, is no greater than the electricity currently used by a series of massive pumping stations necessary to transport water from north to south, over the mountains, and into the Los Angeles Basin – over 2.5 million acre feet per year.

Infrastructure development in California has been paralyzed by litigation and legislation. The result is a self-imposed scarcity of water that can be solved by an all-of-the-above strategy to develop new dams and desalination plants. Civilization requires a footprint, a plain fact that wasn’t lost on previous generations. We’ve learned how to mitigate the worst impact of new infrastructure, but cannot let the ideals of ecological perfection be an excuse to impoverish ourselves.

General obligation bonds to defray the cost to farmers and residents are something the people of California might accept. Then if the rains don’t come for years on end, Californians will still be able to purchase food grown in-state, and enjoy more of the normal amenities of life – a long hot shower. A healthy lawn.

This article originally appeared in the California Globe.

 *   *   *