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Low water conditions reveal the light-colored rink traces along the rock-wall shoreline at Lake Mead, showing the decreased water level from years of drought conditions in the Colorado River basin. Innovative water sharing agreements can help to mitigate this. Photo: Christopher Clark / U.S. Department of the Interior - Bureau of Reclamation

Water Agencies Evolving to Address Changing Realities

California water agencies including the San Diego County Water Authority are exploring ways to better manage sporadic periods of abundant rainfall — part of a larger effort to meet the ever-changing realities they face logistically and economically.

Water Authority General Manager Dan Denham recently discussed the evolution of regional water management on the Southern California Water Dialogue. The Water Dialogues are a monthly forum exploring water-related issues of regional interest.

The backdrop for the discussion is what many call “climate whiplash” — for instance, when three years of record drought from 2020 to 2022 were followed by abnormally high rainfall in 2023. In the future, California could experience shorter but more extreme wet seasons between periods of drought.

View the webinar here.

Creative portfolio approach to water management

At the Water Authority — the agency responsible for long-term water planning in San Diego County — Denham said the lack of regular rainfall and little access to groundwater has forced the Water Authority to be more creative than most water agencies in securing a safe, reliable water supply.

“We embarked upon a 20-to-30-year process to diversify the Water Authority’s supply portfolio. Our board directed a portfolio approach to ensure that we had not only sufficient supplies but also made significant investments in infrastructure,” explained Denham.

“We’ve adopted cutting-edge conservation and techniques. We’ve sponsored legislation at the state level. And we’re at the forefront of many water use efficiency programs,” said Denham.

With those investments and actions as the foundation, the time is right to set a vision for the coming decades. “The future of water in Southern California — of course, reuse is going to be a big component of it — but I do believe a lot of it is going to be sharing resources and developing partnerships,” Denham said.

Advancing long-term water-sharing partnerships

Top (L to R): Mel Katz, chair SDCWA Board; Jim Madaffer, Vice Chair Colorado River Board of CA and SDCWA Board member; Gloria Cordero, MWD’s representative to the Colorado River Board; Adan Ortega, chair MWD Board; J.B. Hamby, Chair Colorado River Board of CA. Bottom (L To R): Dan Denham, SDCWA General Manager; Camille Touton, Commissioner of the U.S. Bureau of Reclamation; Adel Hagekhalil, MWD General Manager; Jamie Asbury, Imperial Irrigation District General Manager. Photo: San Diego County Water Authority

Signing the historic agreement: Top (L to R): Mel Katz, chair SDCWA Board; Jim Madaffer, Vice Chair Colorado River Board of CA and SDCWA Board member; Gloria Cordero, MWD’s representative to the Colorado River Board; Adan Ortega, chair MWD Board; J.B. Hamby, Chair Colorado River Board of CA. Bottom (L To R): Dan Denham, SDCWA General Manager; Camille Touton, Commissioner of the U.S. Bureau of Reclamation; Adel Hagekhalil, MWD General Manager; Jamie Asbury, Imperial Irrigation District General Manager. Photo: San Diego County Water Authority

Denham said investing in a long-term partnership with the Imperial Irrigation District in a water conservation agreement has proved key. “Those types of partnerships have continued and had been successful over the past 20 years,” said Denham.

“This is what our diversification looks like. This is 25 years’ worth of investment in resiliency, transitioning us from an imported water agency with one source of supply to where we’re at today with a really diverse resource mix,” said Denham.

Denham says in addition to maximizing reuse, sharing resources and developing partnerships to share those resources will become vital. The Water Authority signed a landmark agreement with the Metropolitan Water District and the Imperial Irrigation District in late 2023.

“What we were able to do was take advantage of those high runoff years in Northern California, bringing that State Water Project water down to San Diego and leaving some of our Colorado River conserved water in Lake Mead – 50,000-acre feet – which raised the reservoir by six inches. It could not have been done without the partnership that we have in relationships developed over time with the Metropolitan Water District and the Imperial Irrigation District. I look towards more of this to the future,” said Denham.

Flexibility to optimize water resources

QSA-Colorado River-modeling framework-USBR

In October 2003, the San Diego County Water Authority, Coachella Valley Water District, Imperial Irrigation District, Metropolitan Water District of Southern California, State of California and U.S. Department of the Interior completed a historic set of agreements to conserve and transfer Colorado River water.

While planning for drought is necessary, it’s also necessary to devise a plan flexible enough to take advantage of high-runoff years.

“What do you do in those high runoff years, in those years of abundance? Some of that speaks to storage,” explained Denham. “The Water Authority has increased its largest surface water storage reservoir. It’s doubled in size. But the Water Authority — like others in the Metropolitan Water District service area in California, is realizing that those surface water storage reservoirs are pretty full.

“What does that speak to next? Flexibility, and the sharing of resources. If our reservoirs are full, or we don’t have the demands for the investments that we’ve made, whether it’s in the Colorado River supplies or the Carlsbad desalination plant, perhaps there’s another partner in Southern California or in the Lower Colorado River Basin that we can exchange supplies with.

“What I mean by that is we do have supplies that can be managed in a different way,” said Denham.

Established in 1998, the Water Dialogue explores the common interests among Southern California water agencies, environmental organizations, and public interest organizations, and serves as a clearinghouse and advocate for projects, activities, and processes that will improve the quality and reliability of Southern California’s water supply.

The Water Dialogue represents members including the Metropolitan Water District of Southern California, Southern California Watershed Alliance, Sierra Club, West Basin Municipal Water District, Central Basin Municipal Water District, Inland Empire Utilities Agency, Irvine Ranch Water District, Trabuco Canyon Water District, Southern California Water Coalition, Atwater Consulting Group, Jacobs and Caltech/JPL/NASA.

 

Is Seawater Desalination Right for California?

With an unclear future for the state’s freshwater sources, California’s interest in seawater desalination continues to grow. Support for desalination in California is growing. Currently, California has 12 seawater desalination facilities, but only two are of a significant size. Although a key state agency has recently approved plans for two more moderate size facilities, the perception of seawater desalination in the state is quite poor and project proposals face a steep uphill battle.

Diversifying Water Supplies Includes Aquifer Recharge

Bracing for potentially a second consecutive year of dry conditions, California water officials, farmers and researchers participating in an irrigation conference discussed recharging aquifers with stormwater and increased water efficiency among ways to diversify the state’s water supply. The 59th annual California Irrigation Institute conference was held virtually last week, in time for the year’s second manual snow survey by the California Department of Water Resources.

Donner-Summit-2015-Primary-Water Year

La Niña and California’s New Water Year

It’s that time of the year in California, when water managers, climatologists and meteorologists look at the factors that determine what the winter will bring during Water Year 2020-21 (October 1, 2020 – September 30, 2021).

The National Oceanic and Atmospheric Administration recently said that La Niña conditions are present in the tropical Pacific, “with an approximately 85% chance of La Niña lasting through the winter.” Forecasters currently think this La Niña will be on the stronger side. For California, those conditions typically mean a drier winter, with increasingly dry conditions heading into 2021.

Fortunately for the San Diego region, any impacts from La Niña will be lessened because of the region’s development of a diversified water supply portfolio. Following a record number of acres burned from wildfires in 2020, La Niña would only increase fire danger.

NOAA-La Niña-Water Year 2020te.

La Niña continues in the tropical Pacific, with an approximately 85% chance of lasting through the winter, according to NOAA’s October 2020 La Niña update. Graphic: NOAA

Water Year 2020

But, whether the forecasts come to fruition, and what that means for California’s water supply, won’t be fully known until next spring. What we know now is that the water year that just ended (October 1, 2019 – September 30, 2020) varied across the state.

While Northern California was mostly dry, parts of Southern California experienced above average precipitation, according to the California Department of Water Resources. The agency said that the water year ended below average and pointed to the impact of climate change on the California’s water supply.

Impacts of climate change

“California is experiencing the impacts of climate change with devastating wildfires, record temperatures, variability in precipitation, and a smaller snowpack,” said DWR Director Karla Nemeth. “We must continue to invest in our infrastructure to prepare the state to cope with more extreme weather for the state’s needs today and in the future.”

For Water Year 2020, a lack of precipitation resulted in a snowpack of just 50% of average on April 1, as measured by the California Cooperative Snow Survey Program, making it the 10th smallest snowpack in California since 1950, according to the DWR. California’s reservoirs received just a third of the water runoff from precipitation and snowmelt that they did during the same time period a year ago.

The wet season got off to a slow start, but a series of storms in late November and early December pushed 2019 precipitation to near or above average in central and southern California, according to Goldy Herbon, San Diego County Water Authority senior water resources specialist.

Driest February on record

“The wet start didn’t last with dry conditions taking hold over most of the state in January, and then most of California experienced its driest February on record,” said Herbon.

While precipitation picked up in March 2020 for Southern California, statewide snowpack in mid-March was only 38% of average.

“The dry north/wet south precipitation pattern continued in March and April, with some locations in Southern California setting many daily precipitation records, San Diego included, as northern California precipitation levels remained below average,” said Herbon.

Water supplies in “excellent shape”

Despite the below average year in northern California, Herbon said statewide water supplies are in “excellent shape” thanks to above average precipitation the previous year and good reservoir storage. DWR reports that statewide reservoir storage through the end of September 2020 was projected to be 93% of average.

In the San Diego region, a wet spring boosted rainfall totals to near or above normal.

Water Year 2020-Water Supply-La Nina

Regional precipitation during Water Year 2020. Graphic: National Weather Service San Diego