SLO's water use didn't jump 26 percent after all, officials say

A sign directs visitors to downtown San Luis Obispo.
A sign directs visitors to downtown San Luis Obispo. jjohnston@thetribunenews.com

A clerical error by the city of San Luis Obispo led to an inaccurate report by the state that the city’s water use surged 26 percent in August compared to the same month last year, city officials say, noting that usage actually declined by 9 percent that month.

Water use also declined in September by 8 percent year over year, according to the city.

And for the first six months of the year, water usage declined 1.7 percent compared to the same period in 2013 — instead of the 8 percent increase the city previously reported to The Tribune. The decline is mostly due to conservation efforts by Cal Poly.

The errors were discovered after San Luis Obispo’s huge August increase in water usage generated negative publicity statewide while other water suppliers in California were commended for reducing their use during the worst drought in state history.

“There were some people that were angry or confused at first,” said Ron Munds, utilities service manager for the city, referring to the recent state report. “In their hearts everyone knew that they were doing their share to conserve. It was an unfortunate data error — we are only human.”

Munds filed an amended report with the state Tuesday.

In reviewing all the statistics, the city also found that it had been erroneously tracking its water usage for most of the year, not just in August, and is now working to correct those numbers.

Water Division Manager Wade Horton said that error happened because water use by Cal Poly agriculture was mistakenly omitted in the first six months of 2013 and 2014. Once Cal Poly was included, it became clear that conservation efforts by the university in 2014 accounted for most of the decline in water usage.

Horton said the error was discovered as staff was working to find where the latest error happened when reporting the August water use to the state.

The city’s decline in water usage can be attributed to residents’ heightened awareness of the drought, Munds said.

City officials have long said the city has cut water use over several years and is already meeting a 2009 state mandate to reduce water use.

The Water Conservation Act of 2009 required an increase in water use efficiency and sets goals of reducing per capita urban water use by 20 percent by 2020.

The city’s interim goal was 120 gallons per capita per day in 2015 and 117 gallons per capita in 2020. In 2013, the city use was down to 116 gallons per capita, already exceeding 2020 target, said Munds.

San Luis Obispo has three water sources: the Salinas and Whale Rock reservoirs and Nacimiento Lake. The city also uses recycled water for irrigation and construction — which is not included in the figures reported to the state.

In August the city used 499 acre-feet of potable water, a decline of nearly 9 percent from the 547 acre-feet used in August 2013, according to Munds.

The city’s water use also declined in September by about 8 percent. Those numbers were recently reported to the state Water Resources Control Board.

In September the city used about 481 acre-feet of water, compared to 523 acre-feet during the same month a year ago.

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