LACSD utilizes multiple sources of water for its supply: surface water, groundwater, imported water and recycled water. Developing a mixed water portfolio has helped LACSD improve its water reliability. In 2002, the District relied entirely on Lake Arrowhead for its supply. Since that time, LACSD has added two additional potable supplies and developed a recycled water program to meet the needs of its water service area. Potable water comes mostly from local sources and is supplemented by imported water. Local water consists of treated surface water from Lake Arrowhead and groundwater from nearby groundwater wells. Imported water consists of water supplied by the State Water Project through agreements with the Crestline Lake Arrowhead Water Agency (CLAWA).
Lake Arrowhead provides the highest quality water at the lowest cost. LACSD can draw a maximum of 1,566 acre-feet of water per year from the lake. This source is completely supplied through precipitation.
LACSD has two intakes with piping that extend out into the lake. Water is pumped to large booster pumps that convey the water to the treatment facility. Chemicals such as alum and polymer are added to the water to help remove impurities and destroy any bad taste and color. The water is mixed with a static-mixer to distribute the chemicals evenly. The water is then processed through an adsorption clarifier and a small amount of chlorine is added to remove any bacteria. Finally, the water is filtered through layers of sand, gravel and coal before being pumped into storage tanks and delivered to customers.
Click here to see a graphic representation of the surface water treatment process.
The District operates five groundwater wells in the Grass Valley Basin that provide approximately 150-250 acre feet of groundwater per year. This water is pumped to the treatment plant where it is blended with lake water to reduce hardness. The Lake Arrowhead area is comprised of mostly dense, fractured and jointed granite which is not ideal for groundwater wells. Nevertheless, the District continues to identify additional sites for further review and possible development.
The District currently has an agreement to purchase State Water Project water from the San Bernardino Valley Municipal Water District through the Crestline Lake Arrowhead Water Agency (CLAWA). This agreement allows the District to supplement its water supply as necessary.
LACSD developed a recycled water program using membrane filtration and ultraviolet disinfection. This water is used by the Lake Arrowhead Country Club for golf course irrigation.
For more information about the District’s water supply, see the Urban Water Management Plan here.