Yorba Linda Water District's drinking water comes from two sources: local groundwater and "imported water". Approximately 70% comes from local groundwater and 30% comes from "imported water" from the Colorado River via the Colorado River Aqueduct and from Northern California via the State Water Project. The blending of these sources varies according to your geographic location within the District.

YLWD currently operates 10 wells within our service area that draw upon the Orange County Groundwater Basin. The basin, itself, began forming millions of years ago as mountains eroded and ocean sediments filled a deep valley, trapping Santa Ana River water between the layers of accumulated sand and gravel. It holds between 10 million and 40 million acre-feet of water, of which 1.25 million to 1.5 million acre-feet, or approximately half a billion gallons, is usable. The groundwater basin is managed by the Orange County Water District (OCWD), who allows more than 20 cities and water agencies, including YLWD, to withdraw water from the basin, via wells, at a cost of approximately $294 per acre-foot. Unfortunately, even for agencies that have access to the groundwater basin, there is a maximum percentage of water that can be pumped. In the past few years, that number has been between 62% and 70% of an agency's total water portfolio.

The remainder of YLWD's drinking water is "imported" water, purchased through the Municipal Water District of Orange County (MWDOC). MWDOC, in turn, purchases water from the State Water Project and the Colorado River Aqueduct, as part of a consortium of 26 agencies, through the Metropolitan Water District of Southern California (Metropolitan). MWDOC then delivers this water to its own 28 client agencies throughout Orange County, including YLWD, who provide retail water services to the public. The cost of imported water to the retail agencies, such as YLWD, is almost four times the cost of pumping out of the groundwater basin.

The majority of YLWD's operating expenses are variable water costs, which include purchasing water from both OCWD and MWDOC, as well as electricity costs to pump water up to the highest elevations. For fiscal year 2014/15, the variable water costs are approximately $14.9 million, more than 54% of the total budget.