SW

Stormwater Directory

City of McAllen

City of McAllen Public Works / Engineering Department

CityMS4 Phase IIVerified 2026-03

Local Permit / Authorization

Permit Required
Yes
Permit Name
Drainage / Grading Permit
Submit To
City of McAllen Public Works / Engineering Department
Lead Time
Plan review typically 2–4 weeks
Application Method
Submit via City of McAllen permitting portal or in person at 1300 Houston Ave., McAllen, TX 78501
Fee
Contact agency for current fee schedule

Water Quality Standards

Impervious Cover Limit
No citywide impervious cover cap; drainage infrastructure must accommodate design storm flows; FEMA floodplain areas impose elevation and fill restrictions
On-Site Treatment Required
No
Detention Required
Yes
Detention Standard
Detention required to attenuate post-development peak flows to pre-development levels for 2-, 10-, 25-, and 100-year storms per McAllen Drainage Criteria Manual; flat Rio Grande Valley topography requires careful hydraulic routing
Turbidity Standard
No numeric NTU limit; discharges must comply with TCEQ TXR150000 and not degrade Rio Grande or Arroyo Colorado water quality

Local SWPPP / Drainage Plan

Local Plan Required
Yes
Plan Name
SWPPP per TCEQ TXR150000; drainage report required for local permit
PE Stamp Required
Yes
Drainage study prepared by a Texas PE required for sites ≥1 acre. The Rio Grande Valley's subtropical climate produces intense rainfall events, particularly during hurricane season (June–November) and spring convective storms. BMPs must be designed for high-volume, high-velocity runoff events.

Local Inspection Requirements

Requirements
City of McAllen Engineering Department inspects grading permits at key milestones. Hurricane season requires heightened BMP maintenance. Final stabilization inspection required before permit closeout.
Inspector Qualification
No city-specific certification required beyond TCEQ SWPPP requirements

Special Overlay Zones

FEMA Special Flood Hazard Area — Rio Grande and Arroyo Colorado Floodplains
Trigger: Development within FEMA-mapped 100-year floodplain along Rio Grande, Arroyo Colorado, and tributary drains
Restriction: Floodplain development permit required; no net fill without compensatory storage; elevation certificate required; IBWC coordination may be required for projects near Rio Grande
International Boundary Zone (Rio Grande)
Trigger: Projects within the International Boundary and Water Commission (IBWC) jurisdiction near the Rio Grande
Restriction: IBWC coordination required for projects potentially affecting Rio Grande flow or flood risk; no discharge that increases flood risk to Mexico
Arroyo Colorado / South Texas Water Supply Zone
Trigger: Development draining to the Arroyo Colorado, a primary irrigation water supply for the Lower Rio Grande Valley
Restriction: Enhanced water quality controls required; Arroyo Colorado is impaired for bacteria and nutrients; projects must demonstrate no net increase in pollutant loading

Design Manual

Manual Name
City of McAllen Drainage Criteria Manual

Jurisdiction Notes

McAllen and the broader Rio Grande Valley (RGV) represent one of the fastest-growing regions in Texas, driven by cross-border trade and population growth. The flat terrain, subtropical climate, and proximity to the Rio Grande create unique stormwater challenges. Drainage infrastructure capacity is frequently stressed during major rain events. The International Boundary and Water Commission (IBWC) exercises jurisdiction over the Rio Grande and associated infrastructure.

Remember: These local requirements are in addition to the TCEQ state construction permit. Both must be satisfied before breaking ground.
Disclaimer: This information is provided for general reference only. Always verify requirements directly with City of McAllen Public Works / Engineering Department and the agency website before beginning construction.