The headline sounded a bit incredulous: “Manteca water use per capita drops 37.6% in 11 years.”

It appeared on a May 9, 2024 story in The Bulletin regarding Manteca’s municipal water use in April.

Several readers questioned the city’s numbers that led to the 27.6 percent drop.

The numbers were real.

But they deserve explanation.

While ongoing conservation efforts were a factor, the largest contributing factor to Manteca using almost 90 million gallons less water in April of this year as opposed to April of 2013 despite going from 71,890 residents to 91,000 has everything to do with penny pinching.

The city in 2012 started an effort to install shallow irrigation wells for municipal park. The initial wave started coming on line in the summer of 2013, several months after municipal water use hit a near per capita peak of 194 gallons in April of that year.

The main impetus wasn’t saving water.

It was to avoid using costly treated water to irrigate parks.

Irrigating lawns, watering gardens, and other outdoor uses account for just over 50 percent of water use in Central Valley cities like Manteca.

And the biggest water user is the City of Manteca with its parks and other recreational outdoor space that today has surpassed the 450-acre mark.

The city needs to treat water at the well heads of 15 municipal wells used to supply drinking water. In addition, the cost of treated surface water Manteca receives from the South San Joaquin Irrigation District plant near Woodward Reservoir is even higher as it employs much more sophisticated cutting edge treatment processes.

By October 2013, there were 12 parks representing roughly 125 acres on irrigation wells that require between three to four feet of water each year to keep green.

An acre foot of water is roughly enough to meet the needs of a typical Central Valley household of four people, according to the Department of Water Resources.

Altogether the wells in place in late 2013 meant the city could avoid using enough water annually to meet the needs of close to 2,000 people a year.

The City Council at the time, based on the success of the irrigation wells reducing the use of expensive treated water, authorized  moving forward with more irrigation wells at parks.

The wells are financed by the water-related fees assessed on growth since the project ultimately increase the capacity available to accommodate new homes, businesses, and employment centers.

A side benefit of the use of separate wells for park irrigation allowed a steady increase in water pressure in a number of neighborhoods.

That because park irrigation typically takes place during the early morning hours which is the highest peak period for water consumption in the city as people wake up and get ready for work as well as irrigate their own landscaping.

They also help to dewater areas where high water tables that can create problems for buildings, streets, and other structures.

Since the water comes from a lower depth it requires less electricity to pump to the surface which means lower PG&E-related cost needed to keep parks green.

The water at the higher levels is not suitable for drinking as many nitrates and such haven’t been filtered out  as what happens to water working its way down to  deeper water tables.

Since non-potable water such as used to irrigate parks is not included in water consumption data supplied to the state, the switch to shallower wells not connected with the city’s water system to irrigate parks is clearly the biggest factor in per consumption water use dropping.

The per capita use was 194 gallons per day in April 2013 compared to 121 gallons per day last month.

It represents a 37.6 per capita drop in April water use between 2013 and 2024.

As luck would have it, the state picking 2013 as a base year has helped it reduce per capita water growth significantly. Had 2015 been used when most existing parks had irrigation wells in place, the reduction from the baseline year would have been  significantly less per capita.

Manteca was one of the first cities to start converting municipal parks to separate wells.

While the mild weather and rain in  April of  this year helped to obtain a lower per capita use, water conservation measures are clearly working.

Going back a decade or so if it rained in April people would still water lawns despite there being no need to do so.

Also newer homes are more miserly with water use from low-flow shower heads to low-flush toilets.

At the same time washing machines have become more efficient and a number of existing homes have been retrofitted with water saving fixtures.

The city’s requirement for front yards of new homes to be limited to a maximum allowable percentage that can be planted in grass helped reduce the growth of water use.

At the same time the city’s turf program has helped reduce water in existing commercial and residential.

The Manteca turf replacement program dubbed “Lawn to Garden” pays an incentive of $1 per square foot — up to $650 — when a grass lawn is replaced with water-efficient landscaping suited to the area’s  semi-arid climate.

The need to replace lawns and other areas covered with grass that are not native to California is simple. In order to stay green such grass consumes an inordinate amount of water.

For non-native grass to look like what you’d see in the Midwest, South, Eastern Seaboard or even in select Bay Area locations where temperatures are lower and there is more moisture in the air, it requires a huge price with front and backyard lawn areas.

That price is almost 50 percent of all water consumed during the course of a year by a typical Manteca household.

It’s a fairly common water use in the Central Valley, especially with tract-style homes on larger lots.

Reducing water use when it comes to “eye candy” given that most front yards are for curb appeal and not used by neighborhood kids to play flag football, reduces the financial burden for all ratepayers.

The city’s rebate program only applies to front yards and parkways.

If you remove your grass lawn before your design is approved, you will not qualify for the rebate

Contact the city Water Division at 209 456-8468 or email waterconservation@manteca.city to discuss lawn to garden requirements before beginning project.