Frequently Asked Questions for Professionals

When Is a Stormwater Quality Management Plan (SWQMP) Required?

See the Regulations of Harris County for stormwater Quality for specific requirements.

Generally, a SWQMP is required for new development of a 5-acre or larger parcel of land regardless of the amount actually being disturbed. A SWQMP is required for re-development of a 5-acre or larger parcel where 1 acre or more of impervious surface is being added.

Two common exemptions from developing a SWQMP are grandfathering by an existing storm sewer line (pipe) or by filing an Industrial Activities Certificate.

What Is The Stormwater Quality Program?

The Harris County stormwater Quality program was established in compliance with federal (NPDES), and state (TPDES) permitting requirements. The program is responsible for minimizing the impact of potential pollutants to stormwater by comprehensive plan review, followed by inspections of projects before, during, and at completion. Permits are issued, and sites are monitored for compliance within the regulations.

When Are Filter Fabric, Rock Filter Dams, and Reinforced Filter Fabric Fence Used For The Construction Phase?

All pertinent controls must be properly installed before you begin soil-disturbing activities. Consult the SWPPP for the project for additional information.

Do I Need a Notice of Intent (NOI)?

If your site is five acres or larger or part of a larger common plan of development or sale that could potentially disturb five acres or more, you will need an NOI.

Where Do I Post The TCEQ Permit/NOI?

Post the documents at each entrance to the construction site so that the public can readily view the notice: either at every lot or every entrance (for residential subdivisions). Post the NOI in a conspicuous location near the construction entrance for other construction projects.

What Documents Are Required When Renewing a Stormwater Quality Permit Application?

  • Stormwater Quality Permit Application (Renewal)
  • Annual Professional Engineer Inspection Certification
  • Annual Permittee Certification of Proper Operation
  • A $150.00 check or money order made payable to Harris County

What Is The Difference Between The SWPPP and The SWQMP?

These are both booklets that will accompany the drawings at plan submittal. The SWPPP (stormwater Pollution Prevention Plan) is designed to address the pollutants that result from construction phase activities. The SWQMP (stormwater Quality Management Plan) is designed to address the treatment of storm-water run-off after construction is complete.

When applicable, the drawing set should include a SWPPP site plan sheet and associated details. When applicable, the drawing set should include a SWQMP site plan sheet and associated details and calculations. Example SWPPP and SWQMP formats can be found at

If I Receive a Notice Of Inspection, How Much Time Do I Have To Correct The Deficiencies Noted At My Site?

All deficiencies must be collected within 72 hours.

Whom Should I Contact With Permit, Design, or Inspection Questions Related To Stormwater Quality?

For permit/plan review questions: 713-274-3855. For stormwater inspections: 713-274-3861.

How Do I Obtain An NOI?

An NOI can be obtained from the Texas Commission on Environmental Quality (TCEQ). A copy of an NOI can be downloaded from their website at

When Do I Need To Obtain The Harris County Stormwater Quality Permit?

If a SWQMP is required, a Harris County stormwater Quality Permit must be obtained prior to beginning construction activities.

When Is a Stormwater Pollution Prevention Plan (SWPPP) Required?

Harris County requires a SWPPP for all projects that disturb a parcel 5 acres or larger in size. However, please note that TCEQ requires a SWPPP be prepared and be on-site for all projects of one-acre or larger.

When Designing My Stormwater Quality Basin, Do I Require a 24 or 48 Hour Draw Down Time?

The average draw down time should be 24 hours. As an example, the first drop of stormwater run-off should leave immediately and the last drop 48 hours later.

How Can a Project Be Grandfathered?

After October 1, 2003, a project can only be grandfathered if there is an existing storm sewer line (trunk line) sized to serve the development. For this exemption, there can be no detention requirement and the following documentation is required:

  • Original drainage area map
  • Drainage table (calculations)
  • The sheet from an approved set of drawings showing sized pipe
  • Proof that the trunk line was installed prior to October 1, 2003

How Do I Obtain a Certificate Of Compliance (COC)?

Once construction of the permitted feature is complete, an engineer licensed in the state of Texas must submit an As-Built Certificate. We will then conduct a final inspection of the feature and issue the COC. A COC will not be issued until the feature has been cleaned of all sediment and debris that may have accumulated during construction and is completely stabilized. It is a violation of the regulations to operate the feature prior to receiving a COC.

Can I Start Clearing and Grubbing Without a TPDES Construction General Permit?

You must obtain your NOI within 48 hours of beginning construction activities.

How Long The NOI Should Be Posted?

A Notice of Inspection should be posted until a Notice of Termination (NOT) is filed. A Notice of Termination should be filed with the TCEQ when either:

  • Final stabilization has occurred for the portions of the development that are your responsibility; or
  • Another permitted operator has taken control over all areas of the site that have not been finally stabilized; or
  • Silt fences or other temporary erosion controls have been removed, or are scheduled for removal as defined in the SWPPP, or transferred to a new operator if the new operator has sought permit coverage.

How Do I Obtain a Harris County Stormwater Quality Permit?

After the County Engineer has approved your plans you may submit an application. You will be required to provide the application, two (2) copies of the approved plans, an Affidavit from the property owner, a letter from the Municipal Utility District (MUD) or Homeowner’s Association (HOA) (where applicable), a copy of the signed NOI, and two (2) checks. (See the "Guide to Obtaining a Harris County stormwater Quality Permit" for complete instructions.)

When Does The One Year Period For Permit Renewal Begin?

The one-year period begins on the date the Certificate of Compliance is issued.