SW

Stormwater Directory

City of Allen

City of Allen Development Services

CityMS4 Phase IIVerified 2026-03

Local Permit / Authorization

Permit Required
Yes
Permit Name
Grading / Drainage Permit
Submit To
City of Allen Development Services
Lead Time
Plan review typically 2–4 weeks
Application Method
Submit via City of Allen Development Services at 305 Century Pkwy., Allen, TX 75013 or online portal at cityofallen.org
Fee
Contact agency for current fee schedule

Water Quality Standards

Impervious Cover Limit
No citywide impervious cover cap; drainage systems must accommodate design storm flows per City of Allen Design and Construction Standards
On-Site Treatment Required
No
Detention Required
Yes
Detention Standard
Detention required to limit post-development peak flows to pre-development levels for 2-, 10-, and 100-year storms per City of Allen Engineering Standards; Collin County overlay applies for county-maintained channels
Turbidity Standard
No numeric NTU limit; discharges must comply with TCEQ TXR150000 and not degrade East Fork Trinity River, Cottonwood Creek, or Lake Lavon

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 grading permits. Allen is in Collin County and adjacent to Plano and McKinney — large projects may span city boundaries. The East Fork Trinity drains to Lake Lavon, a regional water supply reservoir managed by the North Texas Municipal Water District (NTMWD).

Local Inspection Requirements

Requirements
City of Allen Development Services inspects grading permits at rough grading and final stabilization.
Inspector Qualification
No city-specific certification required beyond TCEQ SWPPP requirements

Special Overlay Zones

East Fork Trinity / Lake Lavon Watershed
Trigger: Development draining to the East Fork Trinity River and Lake Lavon (North Texas Municipal Water District supply reservoir)
Restriction: Enhanced water quality BMPs recommended; coordinate with NTMWD for projects with significant watershed impact on Lake Lavon
FEMA Special Flood Hazard Area
Trigger: Development within FEMA-mapped 100-year floodplain along Cottonwood Creek and East Fork Trinity tributaries
Restriction: Floodplain development permit required from City of Allen Floodplain Administrator; no net fill without compensatory storage

Design Manual

Manual Name
City of Allen Design and Construction Standards

Jurisdiction Notes

Allen is a high-income suburb in Collin County with an affluent, highly educated population and strong corporate presence along the US-75 (Central Expressway) corridor. The city is largely built out in its central areas but continues to develop in its eastern portions. Allen borders Plano to the south and McKinney to the north — large developments near these borders require coordination. The city has a proactive stormwater program and high community expectations for water quality and erosion prevention.

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 Allen Development Services and the agency website before beginning construction.