Environmental Rules in Weld County, CO (2026)
4 county-level rules, plus city-specific rules for 1 city in Weld County, Colorado.
Verified from official government sources
Stormwater Management
Weld County bans dumping anything but stormwater into its municipal storm sewer system, and requires construction sites to control runoff before, during, and after building. The Department of Public Works polices illicit discharges and illicit connections to the MS4 under Chapter 8, Article IX, backing it with notices, fees, and criminal prosecution for anyone who won't clean up a violation.
Stormwater Discharge Rules in Weld County
Some RestrictionsWeld County Code § 8-9-70(A)(1)(a)-(b)
It shall be unlawful for any person to discharge or cause to be discharged into the MS4 any pollutants that cause or contribute to a violation of applicable water quality standards. Subject to Subsection D. below and all applicable county, state or federal discharge regulations, only stormwater may be discharged into the MS4. ... It shall be unlawful for any person to cause pollutants to be dep...
Erosion Control
Any construction site in unincorporated Weld County that disturbs one acre or more of ground needs a Grading Permit from the Department of Public Works, and within the county's MS4 area it must also have an accepted Sediment and Erosion Control Plan before land-disturbing work starts. Working without either permit is a violation of the County Code, not a paperwork formality.
Erosion & Sediment Control Permits in Weld County
Some RestrictionsWeld County Code Sec. 8-12-30; Sec. 8-9-80(B)(4)(a)
Grading permit. Within the designated MS4 area, it shall be unlawful for any person to conduct any activity resulting in, or contributing to, a total disturbed area of greater than or equal to one acre without first obtaining a grading permit from the Department of Public Works. A grading permit is also required for sites less than one acre but are part of a larger common plan of development or...
Flood Zones
Building, filling, or altering land anywhere inside Weld County's FEMA-mapped 100-year floodplain requires a Floodplain Development Permit before work starts. Weld County Code § 23-11-260 makes the permit mandatory countywide in the unincorporated area, reviewed by the county's designated Floodplain Administrator.
Floodplain Development Permits in Weld County
Some RestrictionsWeld County Code § 23-11-260; § 23-11-350(B)
Sec. 23-11-260. - Establishment of FLOODPLAIN DEVELOPMENT PERMIT. A FLOODPLAIN DEVELOPMENT PERMIT shall be required for all USES occurring within the FEMA mapped 100-YEAR FLOODPLAIN to ensure conformance with the provisions of this ORDINANCE and federal and state regulations...B.No permit shall be issued nor shall any START OF CONSTRUCTION begin, DEVELOPMENT occur or BUILDING or STRUCTURE be er...
Flood Elevation Requirements
New homes and additions in Weld County's mapped floodplain must sit a full foot above the base flood elevation, not just at it. Section 23-11-370 sets that one-foot freeboard for new construction and substantial improvements in Zone A, and a companion section extends the same standard to zones with mapped depths, manufactured homes and nonresidential buildings.
Weld County Floodplain Freeboard: One Foot Above BFE
Some RestrictionsWeld County Code § 23-11-370(A)
Per 44 CFR 60.3(b) and CWCB FLOODPLAIN Rule 11, all NEW CONSTRUCTION or SUBSTANTIAL IMPROVEMENT of any residential STRUCTURE shall have the LOWEST FLOOR (including BASEMENT) ELEVATED a minimum of one (1) foot above the BASE FLOOD ELEVATION. Upon completion of the STRUCTURE, the elevation of the LOWEST FLOOR, including BASEMENT, shall be certified by a registered Colorado land surveyor. The cert...
Environmental Rules by City in Weld County
1 cities in Weld County have their own environmental rules rules. Each link goes to that city's dedicated page with code citations.
All Weld County ordinances
See every category we cover for Weld County: parking, noise, fences, fires, animals, pools, and more.
Weld County Ordinance Hub →