Water, Recycled Water & Wastewater Operations

Learn About Moulton Niguel’s Water Management Plans and Programs

Our Water Supply

Moulton Niguel Water District’s service area encompasses approximately 37 square miles, serving over 170,000 in population within the cities of Laguna Niguel, Aliso Viejo, Laguna Hills, Mission Viejo, Dana Point and San Juan Capistrano.

Where Does Our Water Come From?

The District imports all of its potable water from the Metropolitan Water District of Southern California (MET) through its member agency, the Municipal Water District of Orange County (MWDOC), a wholesale importer of water from MET. The District is a customer agency of MWDOC and, as such, receives water from available sources of MET. MET’s sources of water primarily include water imported from the Colorado River and from the State Water Project.

All of the District’s potable water is treated at the Diemer Filtration Plant in Yorba Linda, California, along with the Baker Water Treatment Plant in Lake Forest, California, which is then delivered through three major transmission facilities: the South County Pipeline (SCP), East Orange County Feeder #2 (EOCF#2), and the Allen‐McColloch Pipeline (AMP). The Baker Water Treatment Plant (WTP) will provide approximately one‐third of the treated potable water to the District, and a secondary treatment plant that will treat imported MET water and improve local water reliability.

  • 656 miles of domestic water distribution pipelines
  • 26 steel and 2 pre‐stressed concrete operational storage reservoirs
  • 173 million gallons of total potable water storage capacity
  • 30 pump stations to pump water from lower pressure zones to the higher pressure zones
  • 20 pressure reducing stations and flow control facilities to convey water from high to low zones

The District owns capacity rights in several adjoining water agencies’ reservoirs and pipelines, such as El Toro Water District R‐6 ii reservoir, the Santa Margarita Water District Upper Chiquita Reservoir, the Joint Transmission Main (a joint powers agreement between the District and other water agencies), Eastern Transmission Main jointly owned by the District and the City of San Juan Capistrano, the South County Pipeline, which conveys water from the Allen McColloch Pipeline to several south county water agencies, and the Irvine Ranch Water District Interconnection jointly owned with Irvine Ranch Water District.

The District participates in the South Orange County Wastewater Authority (SOCWA), a joint powers agency comprised of ten governmental agencies, which owns and operates three regional treatment plants and two ocean outfalls. The District also shares treatment capacity with Santa Margarita Water District at a fourth wastewater treatment plant, Plant 3A, which Moulton Niguel owns, operates and maintains.

Moulton Niguel’s wastewater operations include:

  • 501 miles of wastewater pipelines
  • 19 lift stations that pump wastewater over the ridge lines to the various treatment plants for disposal or recycling

Sewer System Management Plan

As required by the State Water Resources Control Board No. 2006-0003-DWQ (WDR Order), Moulton Niguel Water District has developed and implemented a Sewer System Management Plan (SSMP). Moulton Niguel has incorporated and updated the District’s Sanitary Sewer Overflow Prevention Plan and Sanitary Sewer Overflow Response Plan along with existing pre-treatment and engineering programs to complete the remaining SSMP requirements. The SSMP has been developed to facilitate proper funding and management of the District’s sanitary sewer system.

Click here for Moulton Niguel’s Sewer System Management Plan (SSMP)

Click here to view the Resolution of the Board of Directors of the Moulton Niguel Water District adopting and certifying District’s Sewer System Management Plan (SSMP)

Plant 3 A

The District promotes the use of recycled water to reduce dependence on imported water and maximize the reuse of available resources. The District serves recycled water throughout much of its service are via its recycled water distribution system.

  • 25% of the District’s total water demand is met by recycled water
  • 142 miles of recycled water distribution pipelines with 5 pre‐stressed concrete and 6 steel storage reservoirs to service the recycled water system
  • 1,000 acre‐feet of capacity rights in the Upper Oso recycled water reservoir owned by the Santa Margarita Water District
  • 13 recycled‐water pump stations
  • 2 Advanced Wastewater Treatment facilities providing recycled water to landscaped areas in the District
  • 8,000 acre-feet per year of the projected annual demand of the recycled water system

Click here to read the Rules and Regulations for Recycled Water

Learn more about Moulton Niguel’s Recycled Water Retrofit Rebates & Incentives