1. a) No surface area within one hundred (100) feet of the top of the bank of the normal channel of a perennial stream or an intermittent stream shall be disturbed by surface operations and facilities of an underground mining operation, except in accordance with Section 1817.43, unless the Department specifically authorizes underground mining activities closer to or through such a stream upon finding:

   1. 1) That the original stream channel and its associated riparian vegetation will be restored; and underground mining activities will not cause or contribute to a violation of Section 1817.42 and will not adversely affect the water quantity and quality or other environmental resources of the stream.
   2. 2) If there will be a temporary or permanent stream channel diversion, it will comply with Section 1817.43.
2. b) The area not to be disturbed shall be designated a buffer zone and marked as specified in Section 1817.11.

(Source: Amended at 11 Ill. Reg. 8250, effective July 1, 1987)