Caldwell, ID Environmental Rules: Erosion Control (2026)

Caldwell City Code Article 19 of Chapter 4 governs erosion and sediment control for land-disturbing activity of one acre or more within the corporate limits, adopted to safeguard persons, protect property and prevent environmental damage during construction (§ 04-19-01, § 04-19-03). The Caldwell Stormwater Division reviews a complete grading permit application within ten working days and must notify the applicant in writing whether it is approved or deficient (§ 04-19-07). Article 19's general requirements (§ 04-19-11) set the actual field standards: clearing cannot begin until sediment control devices are installed and stabilized, cut and fill slopes are capped at a 3:1 ratio unless Public Works approves a steeper cut for other objectives, and phasing is mandatory on any site disturbing more than thirty acres, with phase size fixed at plan review.

Soil must be stabilized within ten days of clearing or of construction sitting idle, and if seeding has not established within two weeks the department can order reseeding or a non-vegetative fix. Sites must maintain a dedicated construction entrance, control dust with water, sweeping, temporary seed or suppressants, and provide a designated concrete washout area; washing concrete into a street, catch basin or the ground is banned outright. A developer cannot close out permit coverage until the disturbed phase is stabilized, and one who sells parcels to different site operators within a subdivision cannot transfer the permit to escape that duty.