Low-cost Solar Power That Increases the Supply of Fresh Water

Solar panels over 115-foot-wide canal in Hickman, CA (SFGate)

Three years ago we posted about a creative concept for green energy production:

Putting solar panels over California's aqueducts will reduce evaporation and generate green energy.

The California Department of Water Resources is funding the $20 million pilot program with the intention of learning where solar panels might be viable along the state’s 4,000 miles of canals and aqueducts.

In 2025 the program has begun implementation: [bold added]

Near Hickman, California, just outside Modesto, a 110-foot-wide grid of solar panels now tops a section of canal, arching over the gently flowing water. Solar projects have long been a crucial piece of the state’s movement to clean energy, and these panels are part of a new project that’s hoping to do far more than just generate electricity. Dubbed Project Nexus, the $20 million state-funded initiative hopes to better understand whether these installations can be an even more efficient approach to solar energy.

The waterways already irrigate much of the state’s crops, but now they will also cool the solar panels, just by nature of being underneath them, increasing the panels’ efficiency. Meanwhile, the panels will shade the canals, reducing evaporation and suppressing aquatic weeds. Between this installation and a 20-foot-wide section that was completed on another part of the canal in March, the project could generate a total energy output of 1.6 megawatts while producing a host of other benefits.

We seem to have lost the societal vigor to replicate the vast infrastructure projects of the 20th century--the dams, aqueducts, highways, power generation and transportation systems--that elevated the standard of living for every American. However, nothing should stop us from the more modest ambition of improving sections of that infrastructure when opportunities present themselves.

New Traffic Lights

In March we had lamented how the neighborhood had been greatly inconvenienced by an intersection that had been torn up since the beginning of the year.

This week the work was completed, and the new traffic lights were turned on. It did take nearly six months (cue jokes about public works projects), but I must admit that the new lights are big, bright and technologically advanced.

Last year we only had a stop sign; now three stop lights face each direction, and there are two left turn lights on the main boulevard. Based on a couple days of observations, the intersection feels safer especially for pedestrians, and driving speed doesn't seem to have been sacrificed.

Traffic patterns have already changed. For some routes it's advantageous to avoid the lights, for others efficiency dictates that one should seek out the intersection.

All in all, thumbs up.

Bay Area Water Outlook: Underground Storage to the Rescue

Recharge ponds in Campbell (Mercury photo)

We've written before how the replenishment of underground aquifers is a relatively low-cost alternative solution to California's failure to build more reservoirs.

It may take years for the Central Valley to recover, but there is good news already about groundwater levels in the Bay Area. [bold added]

Groundwater provides 40% of the water supply for 2 million people in Santa Clara County. Following more than a dozen major atmospheric river storms this winter, the main water table in the county has risen 35 feet since last June — and is up 51 feet since the most extreme part of the drought in September 2021 — returning to pre-drought levels. The county’s main groundwater basin is now about 90% full.

...Readings taken two weeks ago show that groundwater is just 64 feet below the surface at the district’s main monitoring well in San Jose near the corner of Hamilton and Leigh avenues. That’s the highest level ever recorded since readings began there in 1936.

Similar rebounds have occurred in wells in Sunnyvale, Milpitas and Morgan Hill, where the main index well came up 50 feet since September of 2021 and is now at its highest level in five years.

A similar trend has unfolded at the Alameda County Water District, which provides water to 345,000 people in Fremont, Newark and Union City.

There, the water table has risen 13 feet since Dec. 31 at the Niles Cone Groundwater Basin, which provides 40% of the district’s supplies.

On a State-wide level recovery is less robust:

But some clues are emerging. Of 3,400 wells monitored by the State Department of Water Resources where measurements were taken this spring, 35% showed groundwater increases of at least 5 feet — however, 59% showed no change and 6% showed a decrease when compared with levels a year ago.

Regardless, California's water outlook is much better than it was a year ago.

This year's reprieve should not cause reservoir construction to slow, but historical performance would not make that a safe bet.

There Goes the Neighborhood

The intersection by our house has been torn up since the beginning of the year. It's inconvenienced over a thousand residents who use the street as their main exit from Foster City.

The project didn't seem to be abnormally difficult. Ours is one of four intersections where traffic lights have been scheduled to be installed since 2018. I spoke to one of the workers before work started. He said the delay was caused by a shortage of electricians.

Even when the lights start operation (at the red arrow in the diagram), traffic will be slow. The green-arrowed intersection already has lights; located at the latter's four corners are an elementary school, an apartment building, a shopping center, and a pre-school. Two lights one block apart are a most unusual configuration for a sleepy suburb.

Some drivers will choose to cut through the shopping center, where they can avoid both lights on certain commonly traveled routes. Then the shopping center will put up "patrons only" signs at the entrance points. There goes the neighborhood.

Prioritizing Underground Water Storage

Ways of recharging the aquifer (Water Education Fdn)

We've lamented that California has built very little water storage though

State voters have approved eight water bonds since 2000 that authorize some $27 billion in funding for various water projects.

California is now known for being a State that can't get any important project built, whether it be high-speed rail, low-cost housing, or hydroelectric dams.

It's time to prioritize below-ground storage.

Winter storms have filled California’s reservoirs and built up a colossal Sierra snowpack that’s nearly twice its normal size for this time of year. But years of dry conditions have created problems far beneath Earth’s surface that aren’t as easily addressed.

Groundwater — found in underground layers containing sand, soil and rock — is crucial for drinking water and sustaining farms. During drought years, 60% of California’s annual water supply comes from groundwater. This water is not easily replenished, especially as many groundwater basins across the state are critically overdrafted...

Compared with 2004, the amount of water on and below the ground in 2022 has dropped by nearly 55 cubic kilometers.

Recharge site in Selma, CA.

Hydrologist Jay Famiglietti, a professor at Arizona State University, and NASA scientist Pang-Wei Liu used satellite data and surface measurements to determine groundwater depletion. Of the 55 cubic kilometer total diminishment in California's water supply since 2004, approximately 40 cubic kilometers, or 73% came from groundwater.

Time for a little arithmetic. The acre-foot, which is the quantity of a sheet of water one acre in area by one foot deep, is a standard measure of water volume. The average household uses between one-half and one acre-foot per year. There are 810,714 acre-feet in 1 cubic kilometer. The two largest reservoirs in California, Shasta and Oroville, hold 5.6 and 4.3 cubic kilometers of water, respectively.

To create additional above-ground reservoirs the equivalent of Shasta and Oroville would cost many billions of dollars. If water from the snowpack could be directed to underground storage and then withdrawn when needed (we know that California has already taken out 40 cubic kilometers net), that method would be much more cost effective then building dams. Without human intervention six to nine wet years in a row would be required to replenish the aquifer.

Farmers, hydrologists, and agronomists realized one century ago that underground wells could fill faster if the land were managed to absorb flood waters. Today much more is known about Managed Aquifer Recharge (MAR), but little has been done since we last wrote about this subject seven years ago.

It makes sense to build more recharge stations on land that's already equipped for them. The financial, environmental, and regulatory obstacles are much less than other water-storage alternatives. If Californians blow it again, we are truly an undeserving people.

Barely Hanging On

Folsom Lake is at 54% of its 976K acre-ft capacity

The December rains gave way to a dry January, suspending hopes of an end to the drought. The somewhat good news is that reservoir levels are higher.

thanks to a little snowmelt, water levels were up for all reservoirs from December to January. Lake Mendocino, which has a capacity of 122,400 acre feet, saw the biggest boost from 17% of storage capacity in December to 35% in January. One acre foot is the equivalent of one acre of land covered in one foot of water. Trinity Lake, with a capacity of 2,447,650 acre feet, had the smallest increase from 29% in December to 30% in January...

[CA Dept. of Water Resources hydrology section manager David] Rizzardo said there was a “decent amount of flow into the reservoirs into January, even though weather-wise it was bone dry,” a result of lower elevation snow at 4,000 to 6,000 feet making it’s [sic] way into the reservoirs.

The seasonal storms were sufficiently high to raise California out of the worst drought conditions: [bold added]

For the first time in more than a year, all of California is out of the worst drought category as the state’s overall outlook shows major improvement since the start of the water year.

As of Tuesday, when the U.S. Drought Monitor released its latest map, 0% of the Golden State was experiencing “exceptional” drought — something that hasn’t happened since Dec. 8, 2020.

It appears that we'll make it through the summer but will again have to pray for rain next winter.

Beset by drought, COVID-19, inflation, and people with money and/or prospects moving away, California is barely hanging on.

Infrastructure Spending: Hoping for a Different Result

From July 22nd: Lake Oroville reservoir

Government spending programs are signed to much fanfare, yet always seem to fall short of their goals (or eventually succeed at multiples of the original cost estimates). Your humble blogger nevertheless hopes that the infrastructure bill will produce some progress at improving California's water storage capacity. [bold added]

In California, where a historic drought has depleted reservoirs, state Sen. Melissa Hurtado said infrastructure money is needed to help fund new places to store snowmelt from the local mountains and to repair canals, levees and other methods of conveyance, which are crumbling or in other disrepair. Ms. Hurtado’s Central Valley district has been hit hard with water cutoffs to its big farming sector, and she said some small towns there face possible loss of drinking water due to the shortfall.

“If we don’t act now, it is going to be just catastrophic for mankind,” said Ms. Hurtado, a Democrat.

Maybe there's hope after all: a Democrat used the traditional "mankind" instead of "humankind", and she did not refer to "catastrophic" climate change but water shortages that everyone, global warmists or not, can do something about.