Check Permit Requirements for Your Harris County Property
Harris County contains incorporated cities — including Houston — large unincorporated areas, and extraterritorial jurisdictions where review can fall to Harris County Engineering or to a city depending on the exact location and scope. Drainage criteria, floodplain rules, and permit portals differ between the county and the cities within it. ALFAP TX checks the verified address to identify the likely reviewing authority and the engineering considerations that may apply to a Harris County property.
Preliminary guidance only. ALFAP TX is an informational screening tool. Results are not an official agency determination, FEMA determination, permitting authority confirmation, survey, legal opinion, engineering opinion, inspection, signed or sealed engineering report, or guarantee of approval. Requirements must be confirmed with the applicable authority and, when appropriate, a licensed Professional Engineer.
What this check reviews
County vs city review
Whether the property appears in unincorporated Harris County (county review), inside a city such as Houston, or in an ETJ, labeled as likely until confirmed.
Flood and drainage considerations
The mapped FEMA flood zone and whether drainage or detention considerations appear relevant, since much of Harris County is low-lying and flood-prone.
Windstorm applicability
Whether the property appears within the TDI designated windstorm area, which can include parts of Harris County.
Understanding your result
Harris County Engineering likely
For unincorporated areas, Harris County Engineering commonly reviews permits and applies county drainage criteria. Confirm the reviewer with the county before submitting, because ETJ rules can shift authority to a city.
Inside a city
If the site is inside Houston or another Harris County city, that city's building department and rules — such as Houston's Infrastructure Design Manual — likely apply. ALFAP TX points you to the Houston permit check for city-specific guidance.
Flood and drainage matter
Much of Harris County is in mapped flood zones with flat terrain and clay soils, so drainage and detention are frequently relevant. A Texas civil engineer evaluates the site against the applicable county or city criteria.
When you may need an engineer
- Your property is in unincorporated Harris County and the county requires civil, drainage, or structural documents.
- The site is in a mapped flood zone and a floodplain development permit or drainage analysis may be needed.
- You need detention or grading plans that meet Harris County drainage criteria.
- You want to confirm whether the county or a city reviews your project before preparing the submittal.
Frequently asked questions
Who issues building permits for unincorporated Harris County, Texas?
Permits for property in unincorporated Harris County are commonly reviewed by Harris County Engineering, while property inside a city such as Houston is reviewed by that city. ETJ areas can shift authority depending on the work. ALFAP TX identifies the likely reviewer from the verified address, but confirm the authority with the county or city directly.
How are Harris County drainage rules different from Houston's?
Houston applies the Infrastructure Design Manual through Houston Public Works, while unincorporated areas follow Harris County Engineering drainage criteria. Both address detention, runoff, and stormwater, but the thresholds and methods differ. A Texas civil engineer identifies and designs to the criteria that apply at your site.
Is my Harris County property in a FEMA flood zone?
Much of Harris County is low-lying with mapped flood zones, but flood status varies by exact location. ALFAP TX looks up the mapped FEMA flood zone at the verified address and reports the source and retrieval date. Confirm official flood status with FEMA and the local floodplain administrator.
Does TDI windstorm apply in Harris County?
Parts of Harris County can fall within the TDI designated windstorm area. ALFAP TX checks the property location rather than the county name alone and reports whether windstorm requirements may apply. TDI confirms final applicability and issues certificates of compliance.
What engineering might a Harris County project need?
Depending on the site and scope, a Harris County project may need civil and drainage plans, detention design, grading plans, floodplain documentation, or structural engineering. ALFAP TX flags which services may be relevant; a Texas-licensed Professional Engineer confirms the actual scope for your project.
Other ALFAP TX preliminary checks
Related Alfa Engineering services
When your result suggests engineering may be relevant, these Alfa Engineering services may apply. A Texas-licensed Professional Engineer confirms the actual scope for your project.