Integrated Regional Water Management Plan (IRWMP)

Within Orange County, water resource management has been structured into three (3) primary Watershed Management Areas (WMA):
  1. North Orange County Watershed Management Area
  2. Central Orange County WMA
  3. South Orange County WMA
The 11 watersheds in Orange County were grouped by similar characteristics into these three WMAs. The City is an active participating member of the Central and South Orange County WMAs.
At its essence, the Watershed Management Area is a collaborative framework for municipalities and special purpose agencies to work collaboratively and find synergies across water resource disciplines. Its purpose is to bring together a wide variety of water resource managers in order to achieve more comprehensive and cost effective solutions to Orange County’s water resources needs. Member agencies voluntarily enter into a cooperative agreement that forms the WMA.

Governance includes a policy committee of elected officials, the Executive Committee, to oversee each Watershed Management Area. Senior staff from each member organization form a Management Committee to develop a joint work plan and oversee its implementation. Regular stakeholder forums are held to involve the public and share information across organizations within each Watershed Management Area.
These WMA groups and respective committees meet together on a regular basis to collaborate on water resource issues, including water supply, surface water quality, flood management, wastewater, and natural resource protection. Integrated Regional Water Management Plans (IRWMPs) have been completed for each WMA. Goals and solutions specific to each Watershed Management Area are formulated through consensus with participating stakeholders. Likewise, a custom slate of projects and programs is developed to address the water resource needs of each WMA. The Central and South Orange County WMAs have existing cooperative agreements in place.
Benefits of developing and implementing an IRWMP are:
  • Enhanced collaboration across agencies and stakeholders.
  • Improved responsiveness to regional needs and priorities.
  • Increased efficiency and effectiveness for regional projects.
  • State statute and guidelines require that before IRWM grant funds will be provided that governing boards of participating agencies must adopt the IRWM Plan.
On July 18, 2013, the South Orange County Executive Committee approved an updated 2013 South Orange County IRWMP. The City Council for the City of Lake Forest will consider adoption of the 2013 South Orange County IRWMP at the regularly scheduled meeting on September 3, 2013. Review a copy of the 2013 South Orange County IRWMP (PDF).
More information on the Central Orange County IRWMP may be found at