Harris County, TX Environmental Rules: Stormwater Management (2026)
Key Facts
- Permit required
- SWQ Permit before new development
- Applies to
- Unincorporated Harris County only
- Triggers when
- Project drains into county MS4
- Small-project exemption
- Under 1 acre impervious surface
- Permit term
- Expires 1 year, renewal required
Summary
Unincorporated Harris County requires a Stormwater Quality (SWQ) Permit for new development and significant redevelopment before construction, administered by the County Engineer under the county's NPDES stormwater regulations.
All new development and significant redevelopment within the unincorporated areas of Harris County, Texas without first securing a SWQ Permit, or submitting an Industrial Activity Certification in accordance with Part B, Section 1.05 is prohibited. If any portion of a project drains directly into a Municipal Separate Storm Sewer System owned by Harris County or the Harris County Flood Control District within the unincorporated areas of Harris County, that project must have a SWQ Permit issued by Harris County.
Full Breakdown
Harris County Code of Ordinances Chapter 36, Part B requires anyone doing new development or significant redevelopment in the unincorporated county to obtain a Stormwater Quality (SWQ) Permit before construction, or file an Industrial Activity Certification instead. The rule applies whenever any part of a project drains into a Municipal Separate Storm Sewer System owned by Harris County or the Flood Control District. A handful of exemptions exist, including small linear utility or drainage projects with less than one acre of resulting impervious surface. Permits are administered by the County Engineer and expire one year after final approval, requiring renewal.
Violations & Fines
Building or developing in unincorporated Harris County without a required SWQ Permit is prohibited; Harris County Pollution Control Services and the County Engineer can inspect sites and pursue civil or criminal enforcement.
Frequently Asked Questions
Does this stormwater permit apply inside Houston?
Who administers Harris County's stormwater quality permits?
Sources & Official References
Other rules in Harris County
Texas rules heatmap·Compare Harris County to another location·View the Texas environmental rules overview
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