Buying Land in Harris County, Texas

Houston Covers About a Third of the County -- the Rest Isn't Empty, It's Suburban and Exurban

Case-by-case / verify locally

Harris County spans roughly 1,707 square miles of land; the City of Houston itself accounts for only around 579 of those square miles -- about a third. The remainder splits between dozens of other incorporated cities and suburbs and a large unincorporated area whose population has grown so quickly that it passed the population of Houston-within-Harris-County around 2020 and was on track to become the single largest population component countywide by 2025. That growth is subdivisions, MUDs, and exurban development, not open rural land -- treat any acreage listing here as a candidate for near-term development pressure, not a stable long-term rural holding, and confirm current city-limit and ETJ status with the nearest municipality before assuming county-only rules apply.

Post-Harvey Floodplain Rules Are a Real, Dated Regulatory Shift

Case-by-case / verify locally

Following Hurricane Harvey and the 2018 release of NOAA's Atlas 14 rainfall study (which raised the Houston area's 100-year, 24-hour rainfall estimate from roughly 13 inches to as much as 18), Harris County adopted new floodplain-development rules requiring new construction in unincorporated areas to build to the FEMA 500-year flood elevation rather than the previous 100-year standard, expanded flood-restricted area by roughly 65% outside the City of Houston, and raised required stormwater detention on a tiered scale that can run from 0.20 up to a full 1.0 acre-foot per acre depending on tract size and imperviousness. See our dedicated flood-zones page for Harris County for the specifics -- this is one of the most consequential, and most specifically dated, land-use changes covered on this site.

Every Well Sits Inside the Original Harris-Galveston Subsidence District

Case-by-case / verify locally

Harris County is entirely within the Harris-Galveston Subsidence District (HGSD), created by the Texas Legislature in 1975 as the first district of its kind in the state, specifically to curb the land subsidence that has worsened flooding risk across the region. Most water wells here have required an HGSD permit since 1976; the only wells excluded are those with a casing diameter under 5 inches serving a single-family dwelling. Confirm a specific well or planned well's permit status directly with HGSD (281-486-1105) before counting on groundwater for anything beyond a single home.

The County Runs Its Own Septic Program Through the County Engineer, Not a Health Department

Generally favorable

Harris County holds TCEQ authorized-agent status for OSSF (septic) permitting, but unlike many counties, that program runs through the Office of the County Engineer's Watershed Protection division rather than a public health department -- permits are submitted through the county's ePermits system, and only a licensed installer can call in required inspections. If a parcel needs a septic system, expect a modern, largely online process with the county itself, not TCEQ directly.