Navigating storm water quality regulations in Houston can often be a nebulous process, especially when you are juggling other permitting requirements simultaneously. Let’s take a look at how storm water quality is managed and regulated by the City of Houston.

Rainfall and its Impact

Municipalities and counties in south Texas are quite concerned about what happens when it rains – and for good reason. Just take a look at the last major rain events we’ve had in the Houston metro area over the past few years. Hurricane Harvey, as well as the Tax Day and Memorial Day floods in 2016 and 2015, have forced our public works advocates and property owners to reconsider the true impact of rain. Storm water is obviously a big deal in Houston and Harris County.

The City of Houston and Harris County hold a developer and their designers responsible for the stormwater that leaves a private site. These agencies are often primarily concerned with the quantity or volume of the stormwater discharge, but they also expect a certain quality or characteristic of the water that enters into the MS4, or municipal separate storm sewer system. Enter Storm Water Quality (SWQ) guidelines.

What are the SWQ guidelines for my development?

For general commercial construction and property development, the Environmental Protection Agency (EPA) and its National Pollutant Discharge Elimination System (NPDES) permit program regulates point pollutant sources (i.e. storm water runoff from your property). In the State of Texas, the NPDES program is implemented by the Texas Commission on Environmental Quality (TCEQ) and is referred to as the Texas Pollutant Discharge Elimination System (TPDES). This program also governs wastewater treatment and its treated discharge into public waters.

In the Houston metro area, three agencies coordinate together to issue additional Storm Water Quality guidance as the Storm Water Quality Joint Task Force. The City of Houston, Harris County, and Harris County Flood Control together produce the Storm Water Quality Management Guidance Manual and Storm Water Management Handbook for Construction Activities which all agencies enforce within their ordinance.

The TPDES has general regulations governing rainwater runoff into an MS4 from a property while it is under construction. This guidance can be found in the TPDES Construction General Permit and is used for any development disturbing greater than one acre of land. The Construction General Permit will become a part of your development’s Storm Water Pollution Prevention Plan (SWPPP, SW3P, or SWP3).

Who needs an SWPPP?

The SWPPP will outline your civil or environmental engineer’s professional guidance on how to manage point pollution sources from leaving the site during construction. It utilizes what the industry calls Best Management Practices (BMP) to reduce or eliminate the potential for pollution to enter the MS4. BMPs are defined by the City of Houston as “schedules of activities, prohibitions of practices, maintenance procedures, and other management practices to prevent or reduce the pollution of waters of the United States”.

The SWPPP is required if your site disturbs more than 1 acre during its construction and will include a narrative report and site map that is typically included within the permitted construction documents. The SWPPP differs from the Storm Water Quality Management Plan (SWQMP).

Who needs an SWQ permit?

The SWQMP provides a post-construction narrative of storm water quality management for your property. In real terms, it outlines the operation and maintenance of the long-term structural and non-structural BMPs that mitigate identified sources of pollution on the site during its typical operation and lifecycle.

While your development is in the permitting process at the City of Houston, you may need to also secure and continuously maintain a Stormwater Quality (SWQ) Permit for your property which authorizes the SWQMP on an annual basis. How can you determine whether your development will need an SWQ permit? In the City of Houston, it’s simple — if you are developing a new property that is 1 acre or greater, or you are redeveloping an existing property that is greater than 1 acre and is modifying 0.2 acre or more, you will be required to produce an SWQMP and maintain an SWQ permit with the City of Houston. This permit must include an engineer’s certification and be renewed on an annual basis.

Industrial Activity Certification

If your development includes industrial equipment and material or may be classified as a high-risk commercial development, you may be required to follow additional storm water quality criteria and inspections as outlined in the in the City of Houston code of ordinances and as guided in the TPDES General Permit for Storm Water Discharges Associated with Industrial Activity.

Do you have Storm water quality questions specific to your development or need to fulfill SWQ permitting requirements? If you need guidance, I or one of our consultants at LJA Engineering would love to walk you through your current property and development. I encourage you to call me at 713-580-4149 or email me at

Cover photo credit: Tom Woodward @ Flickr