Environmental Rules in Boulder County, CO (2026)

1 county-level rule, plus city-specific rules for 2 cities in Boulder County, Colorado.

Verified from official government sources

Note: These county rules apply to unincorporated areas of Boulder County. If you live within an incorporated city, that city's own rules apply: see the city list below.

Stormwater Management

Boulder County Public Health bans discharging anything but stormwater into the county's storm drainage system or watercourses, and bans illicit connections to that system outright. Violators face notice-and-abatement orders, criminal prosecution under C.R.S. Title 30, Article 15, and can have the condition declared a public nuisance.

Illicit Stormwater Discharge Rules in Boulder County

Some Restrictions

Boulder County Ordinance No. 2012-4, Sections 6(A)-(B) & 11

No person shall discharge or cause to be discharged into the storm drainage system or watercourses any pollutants or waters containing any pollutants that cause or contribute to a violation of applicable water quality standards, other than stormwater... The construction, use, maintenance or continued existence of illicit connections to the storm drainage system is prohibited. This prohibition e...

Full ordinance details →Official source ↗

Environmental Rules by City in Boulder County

2 cities in Boulder County have their own environmental rules rules. Each link goes to that city's dedicated page with code citations.

BoulderPop. 108,250

5 verified rules • Defensible Space, Erosion Control

LongmontPop. 98,885

4 verified rules • Erosion Control, Flood Elevation Requirements

All Boulder County ordinances

See every category we cover for Boulder County: parking, noise, fences, fires, animals, pools, and more.

Boulder County Ordinance Hub →