South Pasadena Water Supply Remains Tight, But Adequate

South Pasadena Water Tower (File Photo)

Under cloudless skies, South Pasadena faces continuing pressure to conserve water.

By William J. Kelly

South Pasadena remains under a moderate water supply shortage, with restrictions on outdoor water use. Yet, a South Pasadena Public Works Department report issued earlier this fall shows that with continued conservation the city’s four wells alone in the San Gabriel Valley may supply enough water to meet demand without buying expensive imported water from the Metropolitan Water District. That’s partly because the San Gabriel Valley aquifer has risen the past two years from a historic low of 169 feet in 2018 to 199 feet on Nov. 30, 2020, according to the Main San Gabriel Basin Watermaster, the agency that manages the valley’s groundwater. The historic high of the aquifer—which is fed by rain and snow in the San Gabriel Mountains—was 295 feet in 1983.

Residents and businesses are using less water

The other reason city wells alone might be enough to meet South Pasadena’s needs is that residents and businesses use less water than they did a decade ago. From the mid-1990s until 2010 South Pasadena’s water usage hovered around 5,000 acre feet a year. Conservation efforts have reduced that to around 3,500 acre feet a year, about a 30 percent reduction despite modest population growth. And for now, under the Watermaster’s current allocation, South Pasadena can pump as much as 3,568-acre feet in the coming year from its wells without buying imported water or paying the Watermaster to replace water for over pumping.

However, while the city’s groundwater supply looks adequate over the next year, Watermaster Executive Director Anthony Zampiello warns that the area receives ample rainfall some years, but those years “are becoming less frequent, and the periods between are expected to grow longer, drier, and hotter over time.”

The good news for South Pasadena and other cities that depend on the San Gabriel Valley Basin is that recycled water is on the way.

Recycled Water

South Pasadena Mayor Diana Mahmud noted late last month that a recycled water project the Los Angeles County Sanitation District is developing could in coming years pipe cleaned up water from its sewage treatment plant in Carson to the San Gabriel Valley Basin spreading fields, where it would percolate into the ground. The Watermaster expects the project, coupled with other efforts, could supply 60,000 to 80,000 acre feet a year of additional water to the valley’s aquifer. Mahmud said that would effectively eliminate any future need for South Pasadena to buy imported water, which becomes limited and expensive in dry years.