Water Quality Management Plans

All projects requiring discretionary and some requiring ministerial City approval are required to prepare a Water Quality Management Plan (WQMP) in accordance with the Orange County Drainage Area Management Plan (DAMP) and City of Orange Local Implementation Plan (LIP). Chapter 7 of both documents contain information on the types of projects requiring WQMPs, which include new development and redevelopment projects in both the private and public sector.

The WQMP is intended to provide information related to the project's generation and mitigation of water quality pollutants and assessment of hydrological impacts. The WQMP contains project information related to site characteristics, expected pollutants, hydrology impacts, incorporation of structural and non-structural best management practices (BMPs), Low Impact Development (LID) design features, operation and maintenance, and public education and training. The collective information is intended to describe how the project will minimize water quality impacts to downstream water bodies.

Priority and Non-Priority Projects

Projects fall into one of two categories: Priority or Non-priority. The main difference between the two project types is the requirement for priority projects to implement Low Impact Development (LID) design features and for non-priority projects to consider LID where feasible. To determine if the project is a priority project, please check the table within Your Project and a WQMP (PDF).

Project Templates

Once the project has been determined to be priority or non-priority, a WQMP must be prepared using the City of Orange template. Project WQMPs submitted in any other format will not be accepted. To assist in completing the project WQMP, guidance documents have been developed and are being updated as needed.

Design Details Documents

Design Details

The County of Orange and various cities have worked together to create standard design details for use in BMP design. Several standard details are available and the plant palette for use within bioretention areas:


The following maps are also useful in completing the WQMP:

Submittal Process

All priority projects are required to submit Preliminary WQMPs for review by the Public Works Department Surface Water Quality Section along with the required Planning fee prior to submitting the project for review by the City’s Smart Multi-Disciplined Accelerated Review Team (SMART).

The Preliminary WQMP must;
  • Contain all proposed Low Impact Development Design BMP details and calculations,
  • Be approved prior to receiving a Public Works approval recommendation at SMART,
  • Be approved prior to the scheduling of a public hearing before the City Planning Commission or City Council.
Project applicants and WQMP preparers are encouraged to incorporate all water quality requirements at the earliest conceptual design stage of the project to aid in receiving early approval of the Preliminary WQMP, and to avoid potential project redesigns and delays during the formal review process.

Conditions of Approval for WQMPs

Prior to the issuance of any grading permits the applicant shall submit a Project WQMP for review and approval to the Public Works Department that:
  • Prioritizes the use of Low Impact Development principles as follows: preserves natural features; minimizes runoff and reduces impervious surfaces; and utilizes infiltration of runoff as the method of pollutant treatment. Infiltration BMPs to be considered include the use of permeable materials such as concrete and concrete pavers, infiltration trenches, infiltration planters, and other infiltration BMPs as applicable.
  • Incorporates the applicable Routine Source and Structural Control BMPs as defined in the Drainage Area Management Plan (DAMP)
  • Maintains the hydrologic characteristics of the site by matching time of concentration, runoff, velocity, volume and hydrograph for a 2-year storm event.
  • Minimizes the potential increase in downstream erosion and avoids downstream impacts to physical structures, aquatic and riparian habitat.
  • Generally describes the long-term operation and maintenance requirements for structural and Treatment Control BMPs
  • Identifies the entity or employees that will be responsible for long-term operation, maintenance, repair and or replacement of the structural and Treatment Control BMPs and the training that qualifies them to operate and maintain the BMPs
  • Describes the mechanism for funding the long-term operation and maintenance of all structural and Treatment Control BMPs.
  • A copy of the forms to be used in conducting maintenance and inspection activities
  • Recordkeeping requirements (forms to be kept for 5 years)
  • A copy of the form to be submitted annually by the project owner to the Public Works Department that certifies that the project’s structural and treatment BMPs are being inspected and maintained in accordance with the project’s WQMP.
Prior to the issuance of certificates for use of occupancy, the applicant shall demonstrate the following to the Public Works Department:
  • That all structural and treatment control best management practices (BMPs) described in the Project WQMP have been constructed and installed in conformance with the approved plans and specifications,
  • That applicant is prepared to implement all non-structural BMPs described in the Project WQMP,
  • That an adequate number of copies of the project’s approved final Project WQMP are available for the future occupiers.
Prior to the issuance of certificates for use of occupancy or final signoff by the Public Works Department, the applicant shall demonstrate to the satisfaction of Public Works, that the preparer of the WQMP has reviewed the BMP maintenance requirements in Section V of the WQMP with the responsible person and that a copy of the WQMP has been provided to that person. A certification letter from the WQMP preparer may be used to satisfy this condition.

The project applicant shall maintain all structural, treatment and low impact development BMPs at the frequency specified in the approved water quality management plan (WQMP). Upon transfer of ownership or management responsibilities for the project site, the applicant shall notify the City of Orange Public Works Department of the new person(s) or entity responsible for maintenance of the BMPs.

Projects in Hilly Areas

Drainage facilities discharging onto adjacent property shall be designed to imitate the manner in which runoff is currently produced from the project site. Alternatively, the project applicant may obtain a drainage acceptance and maintenance agreement, suitable for recordation, from the owner of said adjacent property.

For projects that will result in soil disturbance of one or more acres of land that will require coverage under the State’s General Construction Permit

Prior to the issuance of a grading permit (include grubbing, clearing, surface mining or paving permits as appropriate) the applicant shall demonstrate that coverage has been obtained under California’s General Permit for Stormwater Discharges Associated with Construction Activity (General Construction Permit) by providing a copy of the Notice of Intent (NOI) submitted to the State Water Resources Control Board and a copy of the subsequent notification of the issuance of a Waste Discharge Identification (WDID) Number or other proof of filing. A copy of the current SWPPP required by the General Permit shall be kept at the project site and be available for review by City representatives upon request.

For projects subject to coverage by the State’s General Industrial Permit as defined by the business’ Standard Industrial Classification (SIC) code

Prior to the issuance of certificates for use and occupancy, the applicant shall demonstrate that coverage under the State’s General Permit for Stormwater Discharges Associated with Industrial Activity (IGP) has been obtained by providing a copy of the Notice of Intent (NOI) submitted to the State Water Resources Control Board and a copy of the notification of the issuance of a Waste Discharge Identification (WDID) Number or other proof of filing.

Special Conditions

Prior to issuance of certificates of use and occupancy or building permits for individual tenant improvements or construction permits for a tank or pipeline, uses shall be identified and, for specified uses, the applicant shall propose plans and measures for chemical management (including, but not limited to, storage, emergency response, employee training, spill contingencies and disposal). The chemical management measures shall be incorporated as an element of a Project WQMP and shall be subject to the approval of the Public Works Department and other specified agencies such as the City of Orange Fire Department, the Orange County Health Care Agency and sewering agencies (as appropriate) to ensure implementation of each agency’s respective requirements. Certificates or permits may be ministerially withheld if features needed to properly manage chemicals cannot be incorporated into a previously completed building, center or complex.

Conditions for Condominiums, Apartments and other projects with CC&Rs

Prior to recording of the final map, a copy of the project’s Covenants, Conditions and Restrictions shall be provided to the Public Works Department for review and approval that includes requirements for maintenance and funding of the project’s structural and treatment water quality best management practices as approved by the City in the project’s WQMP.

Conditions for Coordination of Water Quality BMPs

  • Landscape Plans: Prior to City approval of the landscape plans, the applicant shall review the approved Water Quality Management Plan and ensure the proposed landscape plans are consistent with the project grading plans and show applicable Best Management Practices such as grass swales, detention basins, grass or vegetated buffers, filters, permeable pavers, etc.
  • Building Permits: Prior to issuance of building permits, the applicant shall review the approved Water Quality Management Plan (WQMP) and grading plan to ensure the structure’s downspouts or drainage outlet locations are consistent with those documents. Copies of the building or architectural plans showing the downspouts and drainage outlets shall be submitted to the Public Works Departments for review and approval.
  • Grease Interceptors: Prior to issuance of building permits the applicant shall identify the location of the grease interceptor and provide evidence to the Building Official that the design meets and is consistent with the City's latest adopted building codes.