Collin County
Collin County Engineering Department
CountyMS4 Phase IIVerified 2026-03
Local Permit / Authorization
- Permit Required
- Yes
- Permit Name
- Drainage / Land Disturbance Permit
- Submit To
- Collin County Engineering Department
- Lead Time
- 10–15 business days typical
- Application Method
- Submit application, drainage study, and grading plan to Collin County Engineering Department at 2300 Bloomdale Rd., Suite 3100, McKinney, TX 75071
- Fee
- Contact agency for current fee schedule
Water Quality Standards
- Impervious Cover Limit
- No county-wide impervious cover cap for unincorporated areas; post-construction controls required per TCEQ CGP for sites ≥1 acre
- On-Site Treatment Required
- Yes
- Detention Required
- Yes
- Detention Standard
- Post-development peak discharge must not exceed pre-development rates for 2-, 10-, and 100-year storm events per Collin County Criteria Manual for the Design of Flood Control and Drainage Facilities; detention facility must be maintained under a recorded maintenance agreement
- Turbidity Standard
- Comply with TCEQ TXR150000 construction effluent limits; no separate county numeric turbidity standard beyond TCEQ requirements
Local SWPPP / Drainage Plan
- Local Plan Required
- No
- PE Stamp Required
- No
Collin County does not require a separate local SWPPP beyond TCEQ TXR150000. However, drainage studies and engineering plans submitted with the county drainage permit must be prepared and stamped by a licensed Texas PE. Permit holders must maintain TCEQ SWPPP records on site throughout construction.
Local Inspection Requirements
- Requirements
- Collin County Engineering Department may conduct inspections to verify compliance with approved drainage plans and stormwater controls. Final inspection required prior to permit closeout and acceptance of public drainage infrastructure.
- Inspector Qualification
- TCEQ-qualified inspector required per CGP; county does not impose additional local inspector certification requirements
Special Overlay Zones
FEMA Special Flood Hazard Area (SFHA)
Trigger: Any development within the mapped 100-year floodplain
Restriction: Floodplain development permit required from Collin County; no net fill without compensatory storage; finished floor elevation requirements apply
Lake Lavon Watershed
Trigger: Development within the drainage basin contributing to Lake Lavon (USACE reservoir)
Restriction: USACE may assert jurisdiction over wetlands and waterways; additional Section 404/401 permits may be required; coordinate with USACE Fort Worth District
East Fork Trinity River Corridor
Trigger: Development adjacent to or within the East Fork Trinity River floodplain
Restriction: Enhanced flood control and erosion protection requirements; coordinate with North Texas Municipal Water District (NTMWD) for regional drainage impacts
Design Manual
- Manual Name
- Collin County Criteria Manual for the Design of Flood Control and Drainage Facilities
Official Resources
Jurisdiction Notes
Collin County is one of the fastest-growing counties in the United States. County regulations apply only to unincorporated areas; incorporated cities (Plano, McKinney, Frisco, Allen, etc.) have their own stormwater programs. Projects in ETJs should confirm applicable jurisdiction. The North Texas Municipal Water District (NTMWD) manages regional water supply infrastructure across the county.
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 Collin County Engineering Department and the agency website before beginning construction.