Caldwell, ID Environmental Rules: Stormwater Management (2026)

Under § 04-19-07, no grading permit for uncovering one acre or more of land issues without a SWPPP approved by the Caldwell Stormwater Division, and any development site over one acre, or part of a larger development plan, must file its SWPPP with the Division and obtain Construction General Permit (CGP) coverage through the Idaho Department of Environmental Quality. Section 04-19-09 spells out what the plan must contain: a construction sequence covering stripping, clearing, rough grading, stockpiling, utility and building construction, and final grading and landscaping, identifying the expected clearing start date, how long cleared areas will stay exposed, and the order of clearing, temporary control installation and permanent vegetation establishment.

The plan must also list every erosion and sediment control measure needed throughout construction and permanently afterward, and it must be prepared by a qualified person. Minor field modifications can be authorized in writing by the Caldwell Public Works Department, but changes the Department considers major must go through the same review and approval process as the original plan (§ 04-19-09). The permittee or their agent must make regular inspections of every control measure on the schedule set in the approved plan or permit and submit written inspection reports to the Stormwater Division, which can also enter the property to inspect directly (§ 04-19-13).