Coconino County, AZ Environmental Rules: Stormwater Management (2026)

J. The Community Development Director decides what level of detail that report needs on a project-by-project basis; the ordinance does not print a single countywide detention or runoff-rate number for ordinary development. The zoning ordinance's most detailed stormwater standard instead applies to Utility Scale Renewable Energy Systems. 4 requires that 'the project shall be planned with low impact development stormwater management techniques, as outlined in the Drainage Design Criteria Manual, to capture and infiltrate stormwater and rainwater,' and that 'Biomass Energy Installations shall obtain a stormwater control permit for the facility, including materials stockpiles, from the Arizona Department of Environmental Quality,' with the county reserving the right to add 'additional stormwater controls' as needed.

Both provisions route back to the same technical reference, the county's Drainage Design Criteria Manual, and to the County Engineer's review authority referenced throughout Chapter 5's permit-submittal sections, meaning drainage adequacy for larger or hearing-level projects is evaluated case by case rather than through a fixed subdivision-wide formula.