Manteca is positioned to withstand five consecutive dry years when it comes to water supplies through 2040.

That’s the assumption of an urban water management report the City Council adopted earlier this month.

It is based on the city:

*Not easing up on water conservation measures and taking steps to further promote wise water use.

*Having additional surface water allocation they can take from the South San Joaquin Irrigation District surface water treatment plant.

*Adequate groundwater.

The management report, however, doesn’t factor in actions by the state that could compromise the SSJID’s ability to provide full water delivery to Manteca, Lathrop, Tracy, and farmers.

Nor does it take into account whether the groundwater basin that Manteca draws from once a management plan is put in place to meet state law is being replenished with an amount equivalent in a year that is taken out.

Other concerns have “straws” in the same aquifer Manteca uses including farming operations.

The consulting firm of West Yost stated in the executive summary that “The City is well-positioned to withstand the effects of a single dry year and a five-consecutive dry year drought for any period between 2025 and 2045, even without additional water conservation measures. The City’s drought risk was specifically assessed between 2021 and 2025, assuming that the next five years are dry years.”

The report noted Manteca’s per capita water consumption in 2020 was 164 gallons. The target for water use reduction per capita was established at 179 gallons for 2020 back in 2015.

The plan notes Manteca — at current usage rate and anticipated growth — will be using 30 percent more water in 2040 than it does currently.

That projection  is based on a population of 99,310 in 2040 — roughly 10.000 more residents than  the city has today.

The consultants study placed Manteca’s 2020 population at 83,470. Based on housing growth in 2020, 2021, 2022, and 2023 Manteca has added more than 6,000 residents since then.

The same projection in the study puts Manteca’s population at 87,173 in 2025 — roughly 1,700  less than it has today based on the most recent state Department of Finance estimate of 88,803 issued three months ago

The census count was taken on April 1, 2020.

Besides having allocation remaining in the first phase of the SSJID treatment plant, the city also has water set aside in a future expansion expected to take place around 2040.

To contact Dennis Wyatt, email dwyatt@mantecabulletin.com