How Los Angeles Can Become Water Independent

Repairing leaks, capturing rainwater, and wastewater recycling could end L.A.'s dependence on distant water sources

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As a nation, we dream of energy independence. But in Los Angeles, we wouldn’t dream of water independence. Our local groundwater resources, in this partial desert with Mediterranean weather, provide only 13 percent of what we need.  State politics are now consumed with a proposal by the governor for another massive infrastructure project that will move more water, cost billions, and make us even more dependent.

But we may have to think of this problem differently. All three sources of L.A.’s water imports – the Delta in Northern California, the eastern Sierra, and the Colorado River – are maxed out and likely to decline with global warming. The risks of dependence are growing.

So how can we wean ourselves on distant water? Desalination gets attention, but the energy costs are prohibitive.  Instead, we should be examining every bit of water that is already here in Southern California.

Much of that water is in pipes. Pipes leak. The leaks can be significant. Singapore reduced the amount of water that leaked from its pipes from 40 percent to 12 percent, effectively increasing their water supply by half. But in LA, the Department of Water and Power is replacing aged leaking pipes much too slowly. At the current rate of replacement (about 23 miles per year out of 7,200 miles in the system), it would take 315 years to get through them all—and that’s with pipes that are only designed to last 100 years. We see three to four pipe breakages daily, and L.A. spends about $20 million a year fixing these breaks—and millions more in settlements for damages. It would be better to spend more money accelerating leak repair. Save water and money.

Rainwater capture is also promising.  In just one large rainstorm, 10 billion gallons of runoff, one twentieth of our yearly need, end up in the Pacific Ocean. The technology to capture large quantities is not quite developed, but people are working on it.

Finally, there is the kind of water that we throw away: wastewater. We should recycle it. And we already do. The city’s wastewater treatment facility in El Segundo is an engineering marvel that treats dirty water and sends it into the ocean. Every day, L.A. pours nearly 300 million gallons into the ocean. Yes, that bears repeating: we dump millions of gallons of highly treated water into the Pacific Ocean every day.

Why not keep that water here instead?

Right now, Orange County takes wastewater and treats it to ultra pure levels, producing 10 million gallons a day of water that is superior to bottled water in quality (both by chemical analysis and blind taste tests). In the OC, they have effectively duplicated the process of purification that takes place in nature, only much faster. I have drunk this water, and it tastes like any bottled water. Orange County takes this water and dumps it onto the ground to be naturally filtered, so that it can replenish groundwater to supplement drinking supplies.

With wastewater recycling, L.A. could produce 100 billion gallons of bottle-quality water a year, or about half of our total water needs.  This is a supply that is not dependent upon a distant source or subject to interruption by economics, politics, or damage to the water transport system. There is a plan from LADWP to recycle this water on a small scale, but it does not take full advantage of the opportunity.

Of course, the cheapest water is the water you never use. Thanks to conservation, L.A. uses about the same amount of water as it did 40 years ago, despite massive population growth. But even having the lowest per-capita use of water use among large U.S. cities isn’t enough to save us. That’s why these other options are so important.

Between water recycling, rainwater harvesting, pipe repair, and conservation, we could come very close to eliminating our need for distant water altogether and achieving water independence, possibly forever. Just as important, this “new” water would be relatively fixed in price, not subject to progressively steeper price hikes.

We need to take action now. The longer we wait, the more expensive it gets. The sooner we seek an end to L.A.’s dependence on foreign water, the faster that end will come.

Dr. Ken Murray is a physician who volunteers for the United States Forest Service and the City of Los Angeles. His volunteer activities in water quality led to his sharing in the 2011 United States Water Prize. He wrote this piece for Zocalo Public Square. The views expressed are solely his own. 

8 comments
CamdenCritic
CamdenCritic

This entire discussion is crazy.  Come live on the east coast. It rains and snows. We have limitless fresh water.  We can raise crops without irrigation.You people in the desert are going to end up killing each other for your so called "water rights."

WalterJHorsting
WalterJHorsting

Southern CA is behind a $25 Billion Delta Water Tunnel project that may cost two or three times more.  The twin 40' 40 mile long tunnels will not produce any water for the state.  I suggest 4th generation nuclear desalination for potable water for southern CA.

bigmac1827
bigmac1827

"Orange County takes this water and dumps it onto the ground to be naturally filtered"

There's the problem. People are convinced that water from the ground is intrinsically more clean or healthy, in part due to use of language like this. Pumping the water directly into the drinking supply would be more effective, but politically infeasible due to perceptions about the water.


swagger
swagger

if it's good enough for the astronauts then recycled water should be good enough for everyone if it has been highly purified and then percolated down into the water table.  i think southern california uses a grey water system for landscape watering that is identified by the color coded pink pipes.

aztecian
aztecian

La has the largest concentrated population in cali.  it their water first, and that is just a fact.  La is not dependent on water. 

chokingkojak
chokingkojak

I've resided in LA going on 11 years.   I wholeheartedly support Dr. Murray's suggestions that would lead LA to achieve water independence.  

"...they have effectively duplicated the process of purification that takes place in nature, only much faster" -- why is conservative Orange County able to say this rather than left-leaning Los Angeles?  To LA politicians: Guys, it's embarrassing that LA is getting "dunked-on" by Orange County when it comes to apparently forward-thinking water purification.

Will at least say that LA has, despite population growth, done a nice job with water-use per-capita over the last 4 decades.  To LA politicians and water-use experts:  keep up the great work in that department.


mateosu
mateosu

@aztecian Claiming that the water rightfully belongs to LA does not change the fact that it has to be imported from sometimes extremely distant locations, nor does it negate the costs of doing so. So yes, in this way LA is, in, fact water dependant