Frequently Asked Questions

Q: How can a project be grandfathered?
A: After 10/01/03, a project will only be grandfathered if there are no detention requirements and the project connects to an existing storm sewer line (Trunk Line) sized to serve the development. For this exemption, the following documentation will be required:
1. Original drainage area map (prior to10/01/2001)
2. Drainage table (calculations)
3. Plan sheet showing sized pipe
4. Trunk line installed prior to 10/01/2003

Q: What is the difference between the SWPPP and the SWQMP?
A: These are both booklets that will accompany the drawings at the 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 stormwater run-off after construction is complete.
The drawing set should include an SWPPP site plan sheet and associated details when applicable. When applicable, the Drawing set should include an SWQMP site plan sheet and associated details and calculations. Example SWPPP and SWQMP formats can be found at

Q: When is a Stormwater Pollution Prevention Plan (SWPPP) required?
A: An SWPPP is required for all projects that could disturb a one-acre or larger parcel. The SWPPP must describe and ensure the implementation of practices that will be used to reduce the pollutants in stormwater discharges associated with construction activity at the site and assure compliance with the terms and conditions of the TPDES permit.

Q: When is an SWQMP and SWQ Permit required?
A: See the Regulations of Harris County for Storm Water Quality for specific requirements. Generally, an SWQMP is required for the New Development of a 5-acre or larger parcel of land regardless of the amount actually being disturbed. An SWQMP is required for the re-development of a 5-acre or larger parcel where 1 acre or more impervious surface is added. Two common exemptions from developing an SWQMP are Grandfathering by an existing storm sewer line (pipe) or by filing an Industrial Activities Certificate.

Q: Can we come in and visit/review drawings with you?
A: It Is typically more beneficial to meet after one or more plan reviews or at the beginning stages of a Low Impact Development Project (which requires a pre-project meeting for the approval of plans). 

Q: When are Filter Fabric, Rock Filter Damns, and Reinforced Filter Fabric fences used for the construction phase?
A: All pertinent controls should be installed before you begin soil-disturbing activities.

Q: Do I need a Notice of Intent (NOI)?
A: 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.

Q: How do I obtain an NOI?
A: From the Texas Commission on Environmental Quality (TCEQ). A copy can be downloaded from their website:

Q: Where do I post the TCEQ Permit/NOI?
A: Post 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.

Q: How long should the NOI be posted?
A: A Notice of Termination (NOT) should be filed with the TCEQ when either,
Final Stabilization of portions that are your responsibility,
Another permitted operator has taken control over all areas of the site that have not been finally stabilized
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.

Q: If I receive an inspection notice, how much time do I have to correct the deficiencies noted at my site?
A: You have 72 hours.

Q: When can I submit an application?
A: After the Harris County Engineer has approved your plans, you may submit an application. You will be required to provide: the application, an Affidavit from the property owner, a letter from the MUD or HOA (where applicable), and two checks: $500 (permit fee) and $16 (affidavit filing fee).
(See the Guide to Obtaining a Harris County Storm Water Quality Permit at here for complete instructions.)

Q: If required, when should I obtain my Harris County Stormwater Quality Permit?
A: Prior to beginning construction activities

Q: How do I obtain a Certificate of Compliance (COC)?
A: 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 to operate prior to receiving a COC.

Q: When does the one-year period for permit renewal begin?
A: On the Certificate of Compliance issue date.

Q: Can I start clearing and grubbing without a TPDES Construction General Permit?
A: You must obtain your NOI within 48 hours of beginning construction activities.

Q: What is the Stormwater Quality Program about?
A: To provide land use controls necessary to comply with the Federal NPDES regulations and State TPDES permit No. WQ0004685000 as amended, to protect human life and health and to avoid increasing pollutant levels associated with stormwater.

Q: Where can I get the most up-to-date information from Harris County Permits?

Q: How long does it take to get a Permit approved?
A: We typically shoot for one week.

Q: When designing my Stormwater Quality basin, do I require a 24 or 48-hour draw-down time?
A: The average draw-down time should be 24 hours. So, the first drop of run-off should leave immediately, and the last drop 48 hours later.

Q: Where can I call for inspection questions?
A: James Walls  713-274-3861

Q: Where can I call for Design or Permit questions?
A: Design - Donald Thompson  713-274-3855