(1) The construction of roads in the SMZ is prohibited except when necessary to cross a stream or wetland unless approved by the department under a site-specific alternative practice or as provided in this rule. The construction of roads across streams, wetlands or other bodies of water is not regulated by these rules but may be subject to other state and federal laws and regulations.
(2) Road fill material must not be deposited into the SMZ except as needed to construct crossings.
(3) In order to minimize excavation for road construction on erosive soils characteristic of eastern Montana, an operator may, as an alternative practice without site-specific approval, construct or locate a road inside the SMZ on class 3 stream segments in the eastern zone only wherever:
(a) the slope of the SMZ immediately adjacent to the stream is 10% or less for a distance of at least 25 feet from the ordinary high water mark;
(b) there exists in the outer portion of the SMZ a hillside with slopes in excess of 35%; and
(c) the road is constructed or located on the gentler slopes in such a manner that:
(i) cutting and filling of earthen material is minimized;
(ii) the toe of the road fill is located at least 15 feet from the ordinary high water mark;
(iii) the road is located as far away from the ordinary high water mark as is practical; and
(iv) road drainage features are installed as needed to minimize sediment delivery to streams.