Buying Land in Hidalgo County, Texas

Colonias: the largest concentration in Texas, and a county that changed its own rules

Hidalgo County's colonias story is not a footnote here the way it can be for a border county with a handful of documented settlements -- Hidalgo has more colonias, and more people living in them, than any other county in Texas. A widely cited 2014 assessment from the Texas Secretary of State's Colonia Initiatives Program found that the six counties with the largest colonia populations (El Paso, Maverick, Webb, Starr, Hidalgo, and Cameron) together held 1,854 colonias and 369,482 residents; Hidalgo's own share of that total is large enough that county commissioners and advocacy groups treat it as the defining land-use issue for unincorporated Hidalgo County, not a secondary concern. Like Cameron, El Paso, and Webb Counties, Hidalgo is one of the four Texas counties named directly in Local Government Code Chapter 232, Subchapter E's colonia-prevention platting law, which requires water, sewer, road, and drainage infrastructure before or concurrent with new residential lot sales in the border area.

What sets Hidalgo apart is what the county did on top of that statewide framework. After years of organizing by residents and groups including Texas Housers and ARISE, the Hidalgo County Commissioners Court in October 2018 amended its own Model Subdivision Rules to close a gap that had persisted even under the colonia-prevention statute: new unincorporated subdivisions had not been required to install street lighting, and drainage design standards hadn't kept pace with increasingly severe storm events. The amended rules now require streetlights at every intersection, at cul-de-sacs, and at least every 250 feet along internal streets, funded through a developer escrow of no less than $180 per streetlight per year, alongside upgraded drainage design standards. This is a distinctly Hidalgo County outcome -- confirmed against the county's own posted rulebook rather than the border-wide statute alone -- and it means a new subdivision here faces real, specific infrastructure requirements beyond the generic colonia-prevention baseline.

Hidalgo County Drainage District No. 1: a special district runs drainage and hosts the subdivision rules

Subdivision and drainage review in unincorporated Hidalgo County runs through an institutional structure a buyer coming from most other Texas counties won't expect: Hidalgo County Drainage District No. 1 (HCDD1), a conservation-and-reclamation special district created under Article XVI, Section 59 of the Texas Constitution, not a county department. HCDD1 has financed, built, and now operates and maintains the major drainage channels that move flood and storm water out of the district toward the Gulf of Mexico, and it hosts the county's own subdivision rulebook on its website -- a signal of how central drainage adequacy is to the platting process here. HCDD1 does not itself own or operate sanitary sewer systems or treatment plants, but it does permit connections from wastewater treatment plant effluent, and its boundary gets updated through annexations, typically carried out during the subdivision process for new developments. A buyer planning to subdivide or plat land in unincorporated Hidalgo County should expect HCDD1 involvement as a normal, expected part of that process, not an unusual extra step.

Water: Red Sands GCD in part of the county, Rio Grande irrigation districts elsewhere

Hidalgo County's water picture is genuinely split by geography and use, and it does not match the Rio Grande Valley border counties covered in earlier research. Part of the county -- the Red Sands Groundwater Conservation District's territory in north-central Hidalgo County and along the Hidalgo/Willacy County border -- has real, active local well regulation: Red Sands adopted its current Groundwater Management Plan in September 2023 and has been working to register all wells within its boundary, issue permits, and plug inactive wells as part of its conservation goals. That's a meaningfully different situation from Cameron, El Paso, and Hudspeth Counties, none of which this research found to have a comparable groundwater district covering them -- so a Hidalgo County parcel's well-permitting status genuinely depends on whether it falls inside Red Sands' boundary or not, and that boundary should be confirmed directly with the district.

Outside Red Sands' territory, and for most of the county's irrigated agricultural land, water instead comes from the Rio Grande through a network of Hidalgo County Irrigation Districts -- including District No. 1 and District No. 6, among others -- each holding its own TCEQ certificate of adjudication specifying how much water it may divert for irrigation and, in some cases, municipal use. Hidalgo County Irrigation District No. 1, for example, is certificated to divert up to roughly 85,865 acre-feet a year for irrigation and 1,220 acre-feet for municipal purposes, drawing 100% of that water from the Rio Grande. This is a prior-appropriation, allocation-based water-rights system, not a well or the statewide rule of capture -- a specific tract's water-righted status and current allocation should be confirmed directly with the relevant irrigation district rather than assumed from proximity to the river.

Zoning and septic in unincorporated Hidalgo County

Consistent with the statewide default, Hidalgo County itself has no general zoning authority over unincorporated land -- McAllen, Edinburg, Pharr, Mission, and the county's other incorporated cities each run their own separate zoning codes, and a parcel's status inside or outside those city limits (and any ETJ) should be confirmed before assuming which rules apply. Hidalgo County's Environmental Health Department serves as the TCEQ authorized agent for OSSF (septic) permitting, handling applications, site evaluations, and inspections directly rather than routing them to a TCEQ regional office. Confirm current subdivision, drainage, and septic requirements directly with the relevant office before planning a land split, new subdivision, or septic installation.