State officials on Tuesday reported the largest monthly decline in water use this year as the severity of California's drought hits home, with community wells running dry, farm fields turning to dust and key reservoirs at a fraction of their capacity.Water suppliers reported that consumption fell 11.5 percent in August compared with the year before. That was the first full month of mandatory restrictions and fines for water-wasters imposed by the State Water Resources Control Board in July.Santa Cruz residents conserved far more than the state average as Santa Cruzans cut water use by 28 percent."The trend here is very good," said Felicia Marcus, chairwoman of the board. "It appears the audience is listening, and folks have shifted into gear since we took action."The data is self-reported by water agencies with 3,000 or more customers. Together, the reporting agencies serve 33.5 million Californians, or roughly 87 percent of the state's population.VIDEO: Santa Cruz calls for more water conservationGov. Jerry Brown called on Californians to reduce water use by 20 percent when he declared a drought emergency in January. Californians could face further restrictions if the drought worsens and the coming winter fails to produce adequate snow and rainfall.Marcus says the board is focused on pushing hesitant cities to conserve as much as they can for worse-case-scenarios, rather than achieving an across-the-board 20 percent cut in water use.A similar voluntary survey showed water use actually increased by 1 percent in May. Since then, mandatory reporting shows monthly water use has declined - by 4.4 percent in June and 7.5 percent in July.Of large suppliers serving 40,000 or more customers, the city of Tracy in Northern California had the largest percentage decrease in August water consumption, at 41 percent. Ten actually increased their water use.The figures include residential and business users but do not show per-capita water use. As a result, it's easier for cities such as Sacramento and Fresno that have lacked meters and guzzled water to cut back compared with communities that have long conserved.Take San Luis Obispo, which reported the largest jump in August water use, 26 percent. Ron Munds, the city utilities services manager, said years of conservation brought water use down from 180 gallons per day, per person to about 100 in the last two decades, which helped boost supplies to last seven years of drought."We haven't been pounding the water conservation message out there probably like other cities, but at the same time we are not in a panic situation," he said.Water agencies will start reporting per-capita consumption estimates this month."It allows us to identify those areas that maybe aren't doing as much as they could and leaving alone the folks already squeezing blood from turnip," said Marcus.--- Biggest increases, decreases in August water use ---Water suppliers serving more than 3,000 customers must submit monthly production numbers to the State Water Resources Control Board, which imposed statewide water restrictions in July. The following is from the state water board consumption survey for August.These large suppliers (serving more than 40,000 people) reported the largest decreases in water use among the 394 respondents compared to the previous year:- City of Tracy (San Joaquin County), 41 percent.- California Water Service Company Livermore (Alameda County), 37 percent.- Dublin-San Ramon Services District (Alameda County), 36 percent.- City of Pleasanton (Alameda County), 33 percent.- City of West Sacramento (Yolo County), 28 percent.- City of Santa Cruz (Santa Cruz County), 28 percent.- City of Santa Barbara (Santa Barbara County), 26 percent.- California American Water Company-Sacramento (Sacramento County), 25 percent.- East Valley Water District (San Bernardino County), 24 percent.- Placer County Water Agency, 24 percent.- City of Sacramento (Sacramento County), 24 percent.- Alameda County Water District, 24 percent.___These large suppliers were the only ones to report increases in August water use:- City of San Luis Obispo (San Luis Obispo County), 26 percent.- City of Compton (Los Angeles County), 10 percent.- City of Colton (San Bernardino County), 9 percent.- City of Coachella (Riverside County), 9 percent.- City of Hawthorne (Los Angeles County), 8 percent.- City of San Clemente (Orange County), 4 percent.- City of La Habra (Orange County), 3 percent.- City of San Juan Capistrano (Orange County), 3 percent.- City of South Gate (Los Angeles County), 2 percent.- City of Brea (Orange County), 1 percent.