Larimer County have adopted the Larimer County Stormwater Design Standards, effective September 1, 2023 . These standards apply to the design and construction of stormwater facilities within unincorporated Larimer County.

The Board of County Commissioners adopted the new Standards on August 14, 2023.

Larimer County Stormwater Design Standards (2023)




Mile High Flood District (MHFD) Manual

MHFD Manual, Volume 1: Management, Hydrology, and Hydraulics

MHFD Manual, Volume 2: Structures, Storage, and Recreation

MHFD Manual, Volume 3: Stormwater Best Management Practices (BMPs)


Larimer County Stormwater Design Standards By Section


*CSM = Construction Stormwater Management

Previous Versions



Americans With Disabilities Act (ADA)
Per the Americans with Disabilities Act (ADA), Larimer County will provide a reasonable accommodation to qualified individuals with a disability who need assistance. Services can be arranged with at least seven business days' notice. Please email us at or by calling (970) 498-5700 or Relay Colorado 711. "Walk-in" requests for auxiliary aids and services will be honored to the extent possible but may be unavailable if advance notice is not provided.



Larimer County Engineering Department

Larimer County Engineering Department
200 West Oak Street, Suite 3000
P.O. Box 1190
Fort Collins, CO 80522-1190

(970) 498-5700
Fax: (970) 498-7986

Hours: 8am to 4:30pm, Monday - Friday