Last Updated 07/27/2026
Excerpt from Regulations of Harris County, Texas for Stormwater Quality Management
PART B POST-CONSTRUCTION CONTROLS ON NEW DEVELOPMENT AND SIGNIFICANT REDEVELOPMENT
Section 3 – Ownership and Maintenance of the Stormwater Quality Features
Ownership and maintenance of the Stormwater Quality Features designed and built pursuant to Part B, Section 2.02 of these Regulations shall be according to the following:
The Stormwater Quality Feature shall remain the responsibility of the property owner unless there is a transfer pursuant to Part B, Section 4.04.
Excerpt from the stormwater quality management guidance manual
3.0 STORM WATER QUALITY MANAGEMENT PLANS (SWQMPs)
As required by the NPDES permit, the City of Houston prepared the Proposed Comprehensive Master Plan for New Development and Significant Redevelopment in the City of Houston (the “Master Plan” for the City of Houston), and Harris County/Harris County Flood Control prepared the Proposed Comprehensive Master Plan for New Development and Significant Redevelopment in Harris County (Unincorporated Areas), (the “Master Plan” for Harris County). The master plans were the basis for the City of Houston ordinance and Harris County regulations. The ordinance and regulations require controls to reduce pollutants in discharges to the municipal separate storm sewer system (MS4) after the construction of a development is completed.
Under the ordinance and regulations, proposed new development and significant redevelopment of 5 or more acres will be required to submit Storm Water Quality Management Plans (SWQMPs) that propose structural, non-structural or vegetative controls to reduce pollutants in storm water runoff. The overall goal of the ordinance and regulations and the goal of SWQMPs is to reduce the discharge of pollutants into the municipal separate storm sewer system to the Maximum Extent Practicable (MEP). This manual is intended to provide guidance on the preparation of SWQMPs.
This section describes general planning and implementation procedures for SWQMPs for residential development, commercial development, light industrial development, public facility development, and significant redevelopment of five or more acres. These are general guidelines, and specific site conditions may require additional or modified measures or approaches. The SWQMP requirements discussed here address pollution arising from post-construction activities. The intended function of an SWQMP is to improve storm water quality from the normal daily operating activities of a site for the life of the development. The preparation of Storm Water Pollution Prevention Plans (SWPPPs) for storm water pollution prevention during construction is addressed in a separate guidance document, the Storm Water Management Handbook for Construction Activities. Other types of development/redevelopment projects for facilities that are regulated by EPA’s industrial storm water permitting program should provide storm water quality control measures as required by the EPA.
3.1 Storm Water Quality Management Plan Requirements
The SWQMP functions as a mitigation plan for the potential impacts of pollution from storm water discharge from the normal operating activities of a site for the life of the development. The SWQMP should contain a site description, planned controls, and procedures for maintenance and inspection. The contents of an SWQMP are described below.
3.1.1 Site Description
- Site location.
- Names, addresses and phone numbers of owner and contact person.
- Type of development or redevelopment.
- Nature of activities (Including Standard Industrial Classification Codes).
- Give any existing NPDES storm water permit numbers or provide a copy of the General Permit Notice of Intent (NOI) or NPDES permit application. If the NPDES permit application or NOI is not available, a statement of intent to file an NOI or NPDES permit application should be provided, and a copy of the NPDES permit or NOI, when it is available, should be submitted.
- Estimates of the total site area and the total area affected by the development.
- Site map(s).
- Vicinity map.
- Areas of development.
- Areas not to be developed.
- Drainage areas and their acreage, patterns and approximate slopes anticipated after development.
- Wetlands and surface waters.
- Locations and listing of activities which may generate pollutants and potential discharge, including hazardous materials treatment, storage or disposal facilities, parking areas, loading areas, etc.
- Locations and listing of structural controls, and non-structural controls as applicable, that are identified in the plan.
- Locations where storm water is discharged to the MS4 and the name of the MS4 operator.
3.1.2 Controls
A. Non-Structural Controls
Describe non-structural best management practices (BMPs) and how they will be used at the site.
B. Structural Controls
Structural BMPs should be shown on construction drawings. Supporting data (e.g., specifications, calculations, etc.) should be provided upon request.
3.1.3 Maintenance
Describe procedures and qualified personnel to assure the timely maintenance of control measures.
3.1.4 Inspections
Describe inspection reporting and procedures.
View State Page
Resources
Frequently Asked Questions
What is stormwater compliance in Houston and Harris County?
Stormwater quality compliance in the Houston area is governed by two parallel regulatory frameworks: a City of Houston ordinance that applies within city limits, and Harris County regulations that apply to unincorporated areas of the county. Both were developed from comprehensive master plans prepared under the NPDES permit program and share the same underlying goal of reducing pollutants discharged to the municipal storm sewer system to the maximum extent practicable.
For new development and significant redevelopment of five or more acres, both frameworks require a Storm Water Quality Management Plan (SWQMP) that identifies how stormwater pollution from normal operating activities will be controlled for the life of the development. The SWQMP is not a one time construction document — it governs ongoing maintenance and inspection obligations after the project is complete.
Does my Houston or Harris County project require a Storm Water Quality Management Plan?
If your new development or significant redevelopment project involves five or more acres, a Storm Water Quality Management Plan is required under both the City of Houston ordinance and Harris County regulations. This applies to residential, commercial, light industrial, and public facility development, as well as significant redevelopment of qualifying sites.
Projects regulated under EPA’s industrial stormwater permitting program must also provide stormwater quality controls, but those requirements are addressed under the applicable industrial general permit rather than through the SWQMP process.
If you are unsure whether your project meets the five acre threshold or how it is calculated, AQUALIS can review your plans and help you determine what is required before permitting begins.
What must a Storm Water Quality Management Plan include?
The Houston Storm Water Quality Management Guidance Manual sets out specific content requirements for every SWQMP. At minimum, the plan must include the following.
Site description covering the project location, owner contact information, type of development, nature of activities, any existing NPDES permit numbers, total site area, and site maps showing drainage patterns, wetlands and surface waters, areas that may generate pollutants, locations of structural and nonstructural controls, and where stormwater discharges to the MS4.
Controls describing both nonstructural BMPs and structural BMPs. Structural BMPs must be shown on construction drawings, with supporting data available upon request.
Maintenance procedures describing how and by whom control measures will be maintained in a timely manner.
Inspection reporting and procedures describing how the facility will be monitored to confirm controls remain effective.
AQUALIS can help prepare a compliant SWQMP and develop the maintenance and inspection program your plan requires.
How do I know if my Houston or Harris County stormwater system is at risk of failure or safety violation?
Watch for these warning signs.
Your project was five or more acres and no SWQMP was prepared or submitted. Both the City of Houston ordinance and Harris County regulations require a SWQMP for qualifying projects. If one was not prepared at the time of development, that is an active compliance gap.
Your stormwater quality features are not being maintained per the SWQMP. The Harris County regulations place ongoing maintenance responsibility on the property owner unless the feature has been formally transferred. If the plan calls for inspection and maintenance activities that are not occurring, your facility is out of compliance with the terms of the plan.
Your SWQMP does not reflect current site conditions. The SWQMP is intended to govern operations for the life of the development. If site activities, land use, or stormwater controls have changed since the plan was prepared, the plan may no longer be accurate and may need to be updated.
Recent property purchase. Stormwater quality features and the SWQMP obligations that govern them remain the responsibility of the property owner. If you recently acquired a qualifying development and did not receive the SWQMP or any maintenance records, AQUALIS can assess the current condition of stormwater controls and help you understand your ongoing obligations.
The information on this page is provided for general informational purposes only and is not legal advice. Regulations change frequently — AQUALIS makes no warranty as to the accuracy or completeness of this content, and any reliance on it is at your own risk. Consult a qualified professional or your local regulatory authority to confirm requirements applicable to your specific property.
