We're once again going to be having conversations this summer about water use, and hearing about ever more strict mandates coming down from counties and the state about what we use water for. But is San Francisco's household water use really the problem?

The drought is bad, and it's getting worse. A big swath of the Bay Area was just put in the "exceptional" drought tier last week by the U.S. Drought Monitor, and the rest of the Bay Area is in the second-worst or "extreme" drought category, along with about three-quarters of California.

A new piece in the Chronicle based on some outdated data from the California Department of Water Resources and some comments from experts reminds us, once again, how agriculture is far and away the biggest user of water in the state. And when it comes to per capita water usage in the Bay Area, San Francisco uses the least, and Contra Costa and Santa Clara counties use the most.

Despite the city's ten golf courses, San Francisco used the least water per capita in the region to irrigate large landscapes in 2016 — which is the last year for which this data is available. Being a big and largely arid county, Santa Clara County was tops when it comes to commercial water use by offices and businesses. And with its small population and large amount of agriculture, Napa County comes in a very close third in terms of per capita water use, which is almost evenly split between residential interior use, residential exterior use, commercial, and large landscape watering.

While residential interior use likely shot up in all Bay Area counties last year during shelter-in-place orders, and commercial use likely went down, the overall trend in California has been downward for water use since the last drought, according to experts.

Ellen Hanak, director of the Public Policy Institute of California’s Water Policy Center, tells the Chronicle that despite some rebound in water use during the more recent wet years, California has not rebounded to pre-drought levels of usage. This is thanks, in part, to the public responding to calls to buy water-efficient appliances, get rid of lawns, and plant drought-tolerant plants in their yards.

"We’re shifting toward a future where we’re going to be using water more judiciously and having to manage it in a way that still makes it more available during the drought," Hanak said, in comments to the Chronicle.

So, aside from encouraging our suburban friends to plant some agave and cacti and try to go without washing our cars, what can San Franciscans do to help the drought situation at home?

Mandatory water-use restrictions are not likely in our future, at least this year. The Hetch Hetchy Reservoir, which supplies much of San Francisco's water along with providing water to Alameda, San Mateo, and Santa Clara counties along its 160-mile delivery system, is expected to reach full capacity in the coming weeks. The water level continues to rise from snow melt, as KTVU reports, despite the relatively slim snowfall during the winter, and the reservoir is expected to meet the needs of all its customers.

While it won't fill up three times over the way it would in a normal year, it will reach its 117 billion gallon capacity — more than 30 billion gallons more than the level it was at in the height of the last drought in 2015.

Currently, there are voluntary water-use restrictions being called for in San Francisco for 1,600 irrigation customers — primarily golf courses and parks. But water customers are not being asked to take shorter showers, etc., like we were in the last drought.

Still, curbing those lengthy showers, and being judicious in how you water your gardens won't hurt. And if next winter doesn't bring a ton of rain, we may be looking at more restrictions next summer.

In Marin County, where water supplies are in much worse shape already, mandatory restrictions on residential water use took effect on May 1. These include no washing cars at home, watering lawns only once a week, and refraining from refilling backyard pools.

Photo: Andre Tan