What is El Niño, and What Does it Mean for California?

El Niño, also known as the warm phase of the El Niño-Southern Oscillation (ENSO) cycle, typically occurs every two to seven years, resulting in above-average ocean surface temperatures across the central and eastern Pacific Ocean. As described by the LA Times, this warming can significantly impact weather patterns, shifting a subtropical jet stream that normally rains down on Southern Mexico and Central America up to California and the southern United States.

With the release of the most recent El Niño forecast this past Thursday, Californians are desperately hoping that predictions of it being one of the strongest in the past 50 years prove to be true. In the midst of a four-year drought, a record breaking El Niño could result in a much-needed reprieve for California, giving the dwindling water supply a chance to recharge and providing California with the rain it desperately needs. Up until Thursday, predictions for this year’s El Niño indicated that it was on pace with 1997’s, which is the strongest on record to this day. However, Thursday’s predictions show that this year’s is stronger than it was at this point in 1997, giving it the potential to be the most powerful El Niño on record.

Despite this, predictions do not yet show that this El Niño is strong enough to quench the entire state, and Northern California needs the rain too. As shown in the graphic below, May, June, and July’s predictions for this winter’s El Niño call for a likely wetter-than-average winter from San Diego to San Francisco. This leaves the Shasta Lake and Lake Oroville reservoirs dry, where most of the state’s water supply is stored. So although Southern California has an above-normal precipitation outlook for this winter, it would require a record breaking El Niño to quench the northern part of the state.

Factoring in that California has been dry for much of the last 15 years, and in drought for four years, dry conditions in California are unlikely to end soon. As explained by Kevin Werner, the National Oceanic and Atmospheric Administration’s expert on climate in the western United States, “A single El Niño year is very unlikely to erase four years of drought.” The Weather Channel further confirmed this sentiment, stating “Those hoping for drought relief next winter in the Golden State shouldn’t immediately draw a conclusion that significant rains are ahead in any El Niño year.”

Also, higher than average temperatures in California may result in much of the precipitation falling as rain, which will do nothing to replenish the snow pack. Water stored in the snow pack on mountains allows the water supply to slowly trickle down as it melts, but too much rain at one time could result in mudslides, flooding, and rainwater ending up in the oceans instead of where it’s most needed: in California’s reservoirs.

So with all of these factors combined, what does this mean for California? From a sustainability perspective, Californians should plan ahead for El Niño rather than wait and view it as a saving grace. Once the rains come, little can be done to collect the rainwater without water harvesting systems in place, resulting in flooding and runoff into the ocean. However, the drought has caused many communities in California to require stormwater detention in new building projects, which is a great opportunity for new developments to prepare for this year’s El Niño. These systems filter and detain tens of thousands of gallons of stormwater to help reduce flooding and the impact of large storm events on water treatment facilities, while offering a source for on-site treated water harvesting and reuse. By integrating active and passive rainwater and stormwater harvesting systems, California can better prepare for El Niño rains and better utilize the rainwater it has been waiting for over the past four years.

Wahaso has designed, built, and installed hundreds of water collection and reuse systems across the United States and Canada, including many in California amid the current drought. By designing unique water harvesting systems, Wahaso provides the optimal solution for your building, resulting in more sustainable and environmentally sound water use. To get started, contact us today.

About the Writer: Emily Avellana is a rising senior majoring in marketing at Elmhurst College and a Marketing Intern at Wahaso.