75-5-315. Outstanding resource waters -- statement of purpose. (1) The legislature, understanding the requirements of applicable federal law and the uniqueness of Montana's water resource, recognizes that certain state waters are of such environmental, ecological, or economic value that the state should, upon a showing of necessity, prohibit, to the greatest extent practicable, changes to the existing water quality of those waters. Outstanding resource waters must be afforded the greatest protection feasible under state law, after thorough examination.

(2) The purpose of 75-5-316 and this section is to provide this protection, when necessary, and to provide guidance to the department in establishing rules to accomplish that level of protection.