Reversing the Tide of Imported Tap Water in San Diego County

‍

The water that flows out of San Diego County’s taps, irrigates our lawns, parks, playgrounds, and the fields of our farms is, in reality, more imported than local. Eighty percent of San Diego County’s water supply comes from northern and central California and from the Colorado River by way of massive systems of canals, reservoirs, and pumping plants—a complex network of infrastructures that most of us take for granted.

There is a local water supply, however, flowing down from our hills and mountains and moving beneath our feet in underground reservoirs or aquifers.

At one time, it was San Diego County’s only source of water. And it was a much more sporadic source since it was dependent on rainfall, which in the region’s arid climate could fluctuate wildly. So, it’s no mystery why the region’s Indigenous people would shift their villages with the seasons.

They followed not only the movements of animals they hunted for food, but also the seasonal ebbing and flowing of nearby natural streams.

It’s also no surprise that these ancient humans initiated the first attempts to manage their environment, including the water supply. Richard Carrico, professor in American Indian studies at San Diego State University, had this to say in his book, Strangers in a Stolen Land: Indians of San Diego County from Prehistory to the New Deal:

“At several of these semi-permanent settlements, archaeological investigations have clearly documented stone retaining walls for holding back soils, dams and weirs to control water in the interior valleys, rock bases for large willow storage vessels, and other man-made features of the land.”

Carrico and other researchers have estimated that the Indigenous population for all of San Diego County at the time of first contact with Europeans in 1769 was roughly 20,000. Compared to today’s population of 3.3 million, securing a safe and reliable supply of water has been a crucial element in supporting the needs of the region.

“Developing water” and “water management” are prominent phrases reiterated by the San Diego County Water Authority and other agencies involved in the “water industry.”

Up until the mid-19th century, county farmers and ranchers practiced water management by digging wells, creating earthen dams to form local reservoirs, and keeping careful track of rainfall.

The last half of the century saw growing collective action within and between individual communities and at the county and state levels to promote irrigation and other conservation programs.

The city of San Diego’s first water company was formed in 1873. Other water companies and irrigation districts were created throughout the county, like the Escondido Mutual Water Company and the Vista Irrigation District, formed in 1904 and 1923 respectively.

Local, county, and state water management efforts became more intertwined with the creation of the Metropolitan Water District (MWD) of Southern California in 1928 and the California State Water Project (SWP) in 1960.

The MWD brought a steady supply of Colorado River water to San Diego County, while the SWP linked our water systems to the reservoirs of northern California.

These efforts reflected the increased water needs created by the explosive growth in San Diego County, especially during World War II and its immediate aftermath, which saw the population practically double in only six years.

It was in the midst of World War II, in 1944, that the first countywide water agency, the San Diego County Water Authority (SDCWA), was created “to administer the region’s Colorado River water rights.” This language underscores the dominant role played by “imported water” in the life of the county.

The SDCWA also became a wholesaler of, and coordinator among, a growing number of local water districts across San Diego County seeking to manage this essential resource on the local and regional level.

At the water authority’s founding, it was working with nine member agencies. Today it works with 24. These agencies include those of six cities (including San Diego, Poway, National City, and Oceanside) plus utility and irrigation districts representing unincorporated municipalities and regions (including Fallbrook, Helix, San Dieguito, and Sweetwater).

To an outside observer, looking at the state of water management and development in our county today, one word that seems to stand out is “interdependence.”

The overlap in usage of local water sources becomes evident when looking at the websites of, and talking to officials in, what is referred to as “the water world” or “the water industry.”

For example, talking about “local water” may actually mean water from a reservoir miles away from a particular community.

“We own nine reservoirs in different parts of the county,” says Brent Eidson, deputy director of internal affairs for the city of San Diego’s Public Utilities Department clarifying that ownership refers to the city having “jurisdiction and responsibilities over certain aquifers.”

The geographical overlap in local water management is evident when one looks into the treatment of wastewater, the water that flows out of our homes, workplaces, and farm fields after usage.

The facilities of San Diego’s Public Utilities Department not only treat the city’s wastewater, but also that of 15 other cities and districts, including Chula Vista, Coronado, El Cajon, Poway, Lakeside, Lemon Grove, and Alpine.

Treated wastewater, also known as recycled or reclaimed water, has been used in urban areas for the irrigation of lawns and parks. The possibilities of more advanced water treatment for use in agricultural irrigation is also on the agenda in the county, but it will require time since it involves some major infrastructure upgrades.

In the meantime, “Farmers are irrigating with perfectly potable drinking water,” according to Eric Larson, executive director of the San Diego County Farm Bureau.

In Escondido, the city’s Hale Avenue Sewage Treatment Plant treats and recycles a portion of the city’s wastewater so it’s suitable for irrigation for use in public spaces like parks and medians. But that water “can’t be used for croplands because of its salinity, especially for crops like avocados,” says Christopher McKinney, director of utilities for the city of Escondido.

The city is planning to remedy that with “a series of pipeline projects, a tank project, and an MFRO (Micro-Filtration and Reverse Osmosis) project,” McKinney says.

Reverse osmosis is the process by which the recycled water’s salinity can be reduced “down to a point where it’s usable for farmers,” says Larson.

McKinney says the pipeline phase of the project is currently under construction, and that the construction of the new tank and the MFRO will begin later this year.

Construction of the distribution system for the desalinated water is expected to get underway next year. When the upgraded system goes online in 2021, McKinney adds that “the bulk of the water used for agricultural purposes [in Escondido] will be recycled water.”

The city of San Diego has similar plans as part of its Pure Water Program. This program and other such efforts, like Oceanside’s desalination plant, are important stories regarding water conservation, which in turn means conserving our local aquifers.

In the interim, Eidson says, “We’re poised with our nine reservoirs to capture more of the local runoff. Last year’s rainfall helped.” He adds that they are hoping for more sustained rainfall before this year’s rainy season ends.

He also says his department is continuing to promote “a pretty robust conservation ethics program” which resulted in a 13–14% reduction in water usage since 2013—a number attributed to customers taking steps at home or in their businesses to use water more efficiently.

Officials talk of the differences in definitions and interpretations between the “water world” and the “wastewater world.” One “world” speaks in “acre-feet,” another in “gallons per day.”

And then there’s the matter of what water-wise initiatives will cost to farmers and residential users. There are also discussions, apparently just beginning, about how to “recharge” local aquifers.

Exploring the many aspects and sustainable solutions for the region’s water table will have to be an ongoing story.