Douglas County, CO Environmental Rules: Flood Zones (2026)

The Floodplain Overlay District (Douglas County Zoning Resolution Part 18) is superimposed on the underlying zoning for land the Flood Insurance Study for Douglas County, dated March 16, 2016, and FEMA's Flood Insurance Rate Maps identify as special flood hazard area, under §§ 1-1804 and 1-1805; where county and underlying zone rules conflict, the most restrictive controls. Section 1-1806 flatly prohibits new structures (with narrow exceptions for fish hatcheries, water-related recreation, and homes on nonconforming lots), storage or processing of materials, and junk or salvage yards and landfills.

Anything else, from utility lines and bridges to gravel extraction and reconstruction of storm-damaged buildings, needs a Floodplain Development Permit from the Floodplain Administrator (the Public Works Engineering Director or designee) under §§ 1-1808 and 1-1809, and many uses also need a use-by-special-review permit. Section 1-1811 requires new construction and substantial improvement of residential structures to have their lowest floor, including basement and all mechanical equipment, elevated one foot above the base flood elevation, certified by a registered Colorado engineer, architect, or land surveyor; nonresidential structures can instead be floodproofed watertight to that same one-foot mark.

Manufactured homes need permanent, anchored foundations meeting the same one-foot elevation, and recreational vehicles must either sit fewer than 180 consecutive days, remain licensed and highway-ready, or meet the full manufactured-home permit standards. Encroachments into the floodway itself are barred unless a No-Rise Certification proves no increase in base flood elevation.