Idaho Code § 39-3618: Restriction provisions for new nonpoint source activities on outstanding resource waters.

No person shall conduct a new or substantially modify an existing nonpoint source activity that can reasonably be expected to lower the water quality of an outstanding resource water, except for short-term or temporary nonpoint source activities which do not alter the essential character or special uses of a segment, issuance of water rights permits or licenses, allocation of water rights, or operation of water diversions or impoundments.