If you stand on the edge of the Almaden Dam in San Jose right now, you can feel the ground violently shaking and vibrating beneath your feet. It’s the result of thousands of cubic feet of water rushing out of the reservoir, down into a creek, flowing into the bay. The water’s being released to keep the reservoir from overflowing.
Reservoirs are in good shape
“This spring it’s been really, really full,” says Ken Stumpf. He’s a hydrographer for the Santa Clara Valley Water District, which owns this reservoir. Stumpf measures and manages the water here by looking at how many steel poles stick out of the water.
“There’s probably 100 of them, at least, and they go down by two-foot increments all the way down into the reservoir. We simply take a tape measurer and measure down to the water surface,” he explains.
Today, there are only four poles showing. Last year was pretty different. This reservoir became a sort-of poster child for the drought. It was barely five percent full, so low that strange things usually buried beneath the water, resurfaced.
“You could see a couple of cars in there. It was basically a little puddle,” Stumpf says.
California is a dry state
“We're always in a drought. We live in a Mediterranean climate,” he says.
He says it means we get rainfall all at once, or we get nothing at all. Right now, we just happen to be in a wet year.
The water policy people agree.
“If you think as drought as only rainfall, one could argue the drought is over, but I think that’s the wrong way to think about it, says Peter Gleick, the president of the Pacific Institute.
He says, “The real question is, ‘Do we have enough water in California do to the things we want to do?’ And the unfortunate reality is that even in a wet year like this year, we have water problems.”
California’s bigger water problems
Gleick explains, there are still rural towns without clean drinking water and fish in the bay that don’t have enough fresh water to survive. We’re letting stormwater go down the drain, and, Californians pumped way too much groundwater in the last few years of drought.
“We take too much out. We use more groundwater than nature naturally recharges even in a wet year, and that is simply unsustainable,” Gleick says.
This is a huge problem in the Central Valley, the source of food for much of the state, and nation. That’s where some underground aquifers were pumped so dry that scientists wonder if they’ll ever recover. There’s a new law requiring groundwater management, but people have 20 years to start implementing it. The good news, says Gleick, is that there are simple solutions out there.
“They are cheaper and they are faster and they are more environmentally sound than the traditional things we’ve done in the past,” Gleick says.
The solutions are already out there
Many solutions are being developed and tested at Stanford University. That’s where Richard Luthy is overseeing creative projects, like engineered parks that capture stormwater.
Think of a park that has a big pond, positioned so that the stormwater from all the surrounding neighborhoods will flow down into it.
“What this park-like feature is doing is holding water for a period of time, then running it through some wetlands, and then from there through some final filters before it goes in the ground,” Luthy says.
They’re actually testing this idea right now in Los Angeles, near the Burbank airport, but, this kind of park wouldn’t work everywhere in the Bay Area.
“Like I live on the Stanford campus and if you try to plant a shrub or something, you dig down a few feet and that's just the Santa Clara adobe clay,” he says.
Water won’t seep through that soil so well, but Livermore, Sonoma, South San Jose all have the right soil for percolating parks. So, Luthy says, there are plenty of innovative projects other cities could take on.
“Another thing we could do is to take our wastewater and treat it to a high degree and then reuse it.”
Recycled water means water security
Luthy drives me to a corner of campus to show me what he means. We’re at the Codiga Resource Recovery Center. It looks like a boiler room without walls, a series of pumps and tanks and machines recycle wastewater from the campus.
The campus produces about a million gallons of wastewater a day, and Luthy says this project demonstrates that Stanford has the ability to capture half of that.
“Half a million gallons a day will give us water security for the foreseeable future. I like to say it's our water security for the rest of this century,” he says.
To show me how it works, Luthy hands me off to Sebastien Tilmans, Director of Operations. Tilmans tells to think of the wastewater that comes into the system as a cup full of jam, coffee grounds, sand and water, all mixed together.
“It gives you a good sense for the kinds of physical materials that are in wastewater. We configure our treatment plan to remove those in series. So the first thing is grit removal,” he says.
The wastewater sits in a big settling tank for a while, and the gritty bits fall to the bottom where they can be scraped away. Then, the water is pumped onto the next process, something called a microscreen.
“This machine is about the size three refrigerators, and basically water flows in from one side of the device flows through this rotating screen - a very fine mesh.”
It filters off any remaining waste particles and directs the water to three tall tanks filled with bacteria. This is where biology does its work. Remember the cup and the jam analogy? The coffee grounds and sand have been removed, but the jam’s left. How do they get rid of that?
“We basically feed that jam to bacteria. They eat the food, and what they do afterward is they breathe out methane gas and they exhale that and we can capture that and use it we can burn it to make energy, or we can we can make other really interesting things with it like biodegradable plastic, Tilmans says.
The final result is water that isn’t safe to drink just yet, but safe to use on lawns or to fill up lakes on campus.
This treatment plant’s tiny compared to most municipal ones. It’s not quite mobile, but Luthy and Tilmans say most cities could set these up without having to dig up streets ---- adding to water supplies everywhere.
They say if we keep working on innovations like these, when the next drought comes along, and yes there will be another one, we’ll be more prepared.