STATE OF THE WATER: How LA’s Water Sources are Faring After ‘The Drench’
This blog is the fourth of a five-part series. You can read part one here, part two here, and part three here.
Part 4: How LA’s Water Sources are Faring After ‘The Drench’
Throughout this blog series, we’ve discussed many of the effects this historic wet season has left on LA County. But, with warmer weather fast approaching, one question remains to be answered: after the rains, where is LA County in terms of our water supply?
Well, the response is complicated.
Let’s Look at the Numbers
Emerging From Historic Drought
Just three months ago, about 25% of California was in a severe drought, and just under half of the state was in a moderate drought. As of May 2023 , more than 60% of California is free from any drought classification. LA County is fully out of drought conditions, according to the U.S. Drought Monitor.
When we think of drought, we often think of water – or in this case, the lack of it. And, while precipitation is a major factor in designating a drought, equally important is the availability of water from our primary sources.
In LA county nearly ⅔ of our water is imported through the State Water Project (SWP), the Colorado River Aqueduct (CRA), and the Los Angeles Aqueduct, with the remainder coming from local sources such as groundwater basins, recycled water, and stormwater.
While this year’s rains have brought a welcome and much needed respite from the megadrought our parched state was under, we now look at how this has impacted our main sources of water.
A Rising Snowpack Raises (Almost) All Sources
This year California's snowpack reached record-high levels—40 million acre-feet at its peak in April—that’s enough to hypothetically drape almost 5 inches of water across the entire state of California. At its peak, the snowpack contained nearly as much water as the total capacity of all the state’s reservoirs combined.
This bounty of snow is a bonus to the rain, as it serves as an additional source of water in the summer months. As the weather begins to warm up, the snowmelt will run off the mountaintops and provide additional replenishment to nearby reservoirs, which is then diverted to cities all across LA, California, and the Southwestern states...though this melt also poses the threat of floods to communities across the state.
The unprecedented rain and snowfall was such a boon to the state’s water resources that the LA region received 100% of its State Water Project Allocations for the first time since 2006, up from just 5% last year. While this year’s rains and snow provided much needed reprieve in the short term, we still need to focus on long-term solutions to our ongoing water scarcity challenges to avoid these ‘boom or bust’ cycles.
Colorado River Remains at a Crossroads
Southern California relies heavily on the Colorado River Aqueduct (CRA) for its water supply. However, the effects of over allocating water from the river, combined with the ongoing megadrought in the Southwest, has wreaked havoc on the health of the Colorado River.
Metrics reported from the Water Data website have shown the decline in water levels in Lake Powell and Lake Mead— the Colorado River Basin’s largest reservoirs. In mid-2022, the resevoirs reached their lowest points in over 20 years.
While things are less bleak than when the reservoirs were reported to be on the verge of collapse and water levels were so low that sunken boats and dead bodies were being unearthed, the Colorado River remains at a critical tipping point.
As of June 2023, the current water levels in Lake Mead and Lake Powell stand at 8,081,062- and 9,141,694-acre feet, respectively (a positive change of 11% and 35%, respectively since June 2022). But while these gains provide some relief, the long-term effects of this wet season are not nearly enough to undo the damage that has been caused by severe drought and overconsumption.
As a result, concerns over the future of the river have become an increasingly contentious issue, and there is a growing chorus of federal leaders who have called on states to reduce their reliance on the CRA. The health of the Colorado River has a resounding impact on various states in the Southwest, but as the largest consumer of water from the CRA, California stands to be one of the most affected.
Other lakes and reservoirs that help supply water to the LA region, such as Mono Lake, are facing the same fate. The rains have provided a temporary reprieve from collapse, but these bodies remain far from healthy and secure.
Groundwater – An Often Neglected Source Starts to Rebound
The LA region is blessed with plentiful groundwater basins located right under our feet.
Unfortunately, decades of pollution have contaminated many of these aquifers, while the hardcape that is so prevalent throughout the region has limited the natural recharge of these basins from our rains. Luckily, water agencies such as the LA Department of Water and Power (LADWP) and the Water Replenishment District (WRD) are undertaking largescale groundwater cleanup efforts to allow us to more fully tap into these supplies. But before the drench, our groundwater levels in many of these basins were extremely low. In fact, combined, our groundwater basins had a staggering 1.5 million acre-feet of available storage capacity – enough to serve the entire population of LA County for nearly 18 months (assuming 80 gallons per person per day water withdrawal).
At the end of the 2023 water year (October 2022 to present), LA County Public works estimated that stormwater capture at groundwater recharge facilities reached 515,200 acre feet (or 167.92 billion gallons). This is enough water for more than five-and-a-half million residents in Los Angeles County for an entire year! Countywide, our groundwater wells have received a much-needed boost. As of June, 92 (or 65%) out of the 142 monitored wells in LA County are at or above normal levels.
As highlighted in our last blog, which focused specifically on the Central and West Coast Basins managed by WRD, the agency’s operating range is at 95% of Optimum Quantity levels as of May 2023 (as opposed to 20% a year ago), though significant storage space (an estimated 450,000 acre-feet) is still available.
The story is similar with the San Fernando Groundwater Basin, the primary source of groundwater for the City of LA. According to LADWP, the 130,000 acre-feet of stormwater captured this wet season by the City of Los Angeles still has not filled the 500,000 acre feet of storage capacity that was available before the rains.
Where does that leave LA County? In a better place, but long-term planning is needed!
Looking at the numbers, LA County has made a vast improvement from where it was just a couple of months ago—we are fully out of drought-like conditions—and our local water supplies have received a much-needed boost. But, we’re not out of the woods yet. Despite the large snowpack, the Bay-Delta and Colorado River, as well as many of the lakes and reservoirs that serve the LA region, remain in crisis. And our groundwater, while significantly replenished, still holds significant capacity for even more recharge.
If these whiplashing wet and dry spells have taught us anything, it is that the question is no longer about being in or out of drought. Rather, it’s about our ability to respond to the increasing volatility of the climate as a result of global warming.
In the face of this “new normal” of drier dries and wetter wets, conservation needs to become a way of life, even during wet years. And, LA’s infrastructure must adapt to capitalize on these wet seasons. Through investments in green stormwater capture solutions we can increase our water independence and help protect our water sources from increasing depletion. One wet season will not pull us out of drought. But, a long-term approach with community input and the right systems in place will put us on the path toward water resiliency, and that’s a step in the right direction.