Central OC Watershed Management Area

Efforts to develop a combined Integrated Regional Water Management (IRWM) Plan for the North and Central OC Watershed Management Areas began in February 2017.  The comment period for the draft plan (The OC Plan) closed on December 22, 2017.  Responses to the comments are being prepared and the final draft plan will be completed by the end of February 2018. 

The Call for Projects to build the IRWM Project List is now open through February 21stProjects can be submitted via the new North/Central IRWM website/Data Management System (DMS); instructions for submitting projects are provided below.  To provide agencies and stakeholders additional guidance on submitting projects using the website/DMS, two technical assistance workshops have been scheduled for the following:

  • January 16, 2018, 2:30-3:30 pm
  • February 6, 2018, 2:30-3:30 pm

Both workshops will be held at Orange County Public Works, 2301 North Glassell Street in Orange - Conference Room 2A.  The project team will demonstrate how to submit projects using the website/DMS, assist with project submittal, and answer questions for those needing assistance. 

Project Submittal Process

  1. Download the IRWM Project Solicitation Excel Score Sheet from the Project Submittal page of the website/DMS.
  2. Complete the IRWM Project Solicitation Excel Score Sheet and save locally using the designated file nomenclature ("NCWMA_OrgName_ProjectName").
  3. Drag and drop saved IRWM Project Solicitation Excel Score Sheet into web submission box on the left-hand side of the Project Submittal page of the website/DMS.  (If you would like to add more information about an existing, previously funded project, please also use this process to submit photos, data, reports, etc.).
  4. Complete the "Project Submittal Form" online through the Project Submittal page of the website/DMS, including geospatial project location (dropped pin, lat/lon, or address), and click "Submit Entry" button.
  5. County staff will receive both the Project Submittal Form entry and associated geospatial data as well as the IRWM Project Solicitation Excel Score Sheet; after these are reviewed briefly for completeness, they will be added to the IRWM Project Data Explorer map on the website/DMS and the IRWM Project List.  County staff will strive to have all projects uploaded within three business days of submittal, barring any technical issues.

If you have additional questions regarding the development of The OC Plan and associated Call for Projects process, please refer to the list of North/Central IRWM Plan FAQ.


The Central Orange County (COC) Watershed Management Area (WMA) encompasses the Newport Bay Watershed with an area of approximately 154 square miles. Cities within the WMA include Irvine, Newport Beach, Tustin, and portions of Costa Mesa, Laguna Hills, Laguna Woods, Lake Forest, Orange, and Santa Ana. San Diego Creek and Santa Ana-Delhi Channel are the major inputs into the Newport Bay Watershed. The COC WMA includes three Critical Coastal Areas (CCAs), two Areas of Special Biological Significance(ASBS), nine miles of coastline, and a functioning estuary designated as a State Ecological Reserve. The entire area within the WMA drains to the CCAs and ASBS, which means conditions in the WMA significantly impact the coastal ecosystem. Water supplies are diverse including groundwater, desalted groundwater, recycled water, and imported water.

Integrated Regional Watershed Management Plan (IRWMP) Efforts

Phase I

In, 2007, the County of Orange led development of this IRWMP to meet Proposition 50 guidelines. 
Click link Phase I Central Orange County Integrated Regional and Coastal Watershed Management Plan

Phase II

The City of Newport Beach was awarded a planning grant to prepare an Integrated Regional Coastal Watershed Management Plan.
 Click link Phase II Integrated Regional and Coastal Watershed Management Plan

Central OC WMA

Phase III

In 2012, the County of Orange completed the third phase of the COC WMA IRWMP. This Phase III IRWMP was developed to meet proposition 84 guidelines and priorities. 

IRWM Plan can be accessed by Section:

Executive Summary, Table of Contents, Acronyms 

  1. Introduction 
  2. Governance 
  3. Regional Description 
  4. Objectives 
  5. Resource Management Strategies 
  6. Projects 
  7. Data Management 
  8. Finance 
  9. Technical Analysis 
  10. Coordination with Existing Local/Regional Plans 
  11. Stakeholder Involvement 
  12. Climate Change

    Appendix A-Projects