Weld County, CO Environmental Rules: Flood Elevation Requirements (2026)

Weld County's Floodplain Management Ordinance, Article XI of Chapter 23, is administered by a designated Floodplain Administrator inside the Department of Planning Services and applies countywide to every Special Flood Hazard Area shown on the county's FIRM maps. A requires that any new residential structure, including additions counted as substantial improvements, have its lowest floor, basement included, elevated a minimum of one foot above the base flood elevation. A Colorado-registered land surveyor must certify that finished elevation on FEMA's own Elevation Certificate form once construction is done.

Nonresidential buildings get a choice under Subsection B: elevate the lowest floor the same one foot above BFE, or dry-floodproof the structure so it is watertight to that same one-foot mark, with a licensed engineer or architect certifying the design. Subsection C adds venting rules for enclosed areas below the lowest floor used only for parking or storage, requiring at least two openings on different walls sized to one square inch per square foot of enclosed area. The same one-foot freeboard reappears for Zones A1-A30, AE, AH and AO under Section 23-11-380, for manufactured homes placed in those zones, and even for oil and gas facilities and storage tanks sited in the floodplain, which the ordinance requires to be elevated, floodproofed or flood-vented. A Floodplain Development Permit from the Floodplain Administrator is the gate that triggers all of this before a building permit issues.