17.24.104 EXPLORATION (TEMPORARY) ROADS
(1) Insofar as possible, all roads must be located on benches, ridge tops and flatter slopes to minimize disturbance and enhance stability.
(2) Road widths may not exceed a 14 foot single lane standard. Turn-outs may be constructed according to the licensee's needs, but the turn-out area may not exceed 30 feet in total width.
(3) No road may be constructed up a stream channel proper or so close that material will spill into the channel. Minor alterations and relocations of streams may be permitted if the stream will not be blocked and if no damage is done to the stream or adjoining landowners. No alteration that affects more than 100 linear feet of the channel of a flowing stream may be approved by the department without advice from the Department of Fish, Wildlife and Parks. Any stream channel alterations must comply with Title 75, chapter 5, MCA.
(4) Road gradients must be kept low except for short pitches to take advantage of topography. Maximum sustained grades may not exceed 8%. Pitch maximum may not exceed 12% and may not be over 300 feet in length.
(5) Insofar as possible, the licensee must keep road cuts reasonably steep to minimize surface disturbances. Cut slopes may not be steeper than 1:1 in soil, sand, gravel, or colluvium; 1/4:1 in lake silts, or more than 0:1 in rock. Where necessary to prevent significant sloughing or slumping, the top of road cuts must be rounded back to a more gentle slope. In selecting a slope angle, to prevent slope failure the licensee should consider at least the following factors: the nature of the material, compaction, slope height and moisture conditions.
(6) A ditch must be provided on both sides of a throughcut and, with the exception of outsloping roads, on the inside shoulder of a cut-fill section, with ditch relief cross drains (water bars) being spaced according to grade. Water must be intercepted before reaching a switchback or large fill, and be routed and released below the fill or switchback, not over it.
(7) Streams must be crossed at or near right angles unless contouring down to the stream bed will result in less potential stream bank erosion. Structure or ford entrances and exits must be constructed to prevent water from flowing down the roadway.
(8) Culverts must be installed at prominent drainage ways, small creeks and springs. Upon abandonment of the road, culverts must be removed and the drainage way reopened. Such culverts must be sufficient to handle runoff expected from a statistical five-year storm and, where necessary, the area adjoining the culvert must be protected from erosion by adequate, inert rock riprap.
(9) Trees and vegetation may be cleared for only the essential width necessary to maintain soil stability and to serve traffic needs. Trees must be felled prior to road construction. When sideslopes are 15% (8.5º) or less, trees and other vegetative debris from clearing operations must be completely disposed of, stockpiled at specified areas, or used as a sediment filter below the road cut. When sideslopes are steeper than 15% (8.5º) , trees and vegetative debris shall be piled neatly below and parallel to the toe of the fill.
(10) Drainage facilities (such as culverts and water bars) must be installed as road construction progresses.
(11) Adequate diagonal drainage barriers (i.e., water bars, drain dips or similarly effective features) must be placed at the following specified intervals:
(12) Roads must be outsloped whenever possible. If roads are to be used during snow season, insloping with proper drainage consideration is acceptable for vehicle safety reasons.
(13) Snowplowing must be done in such a manner that runoff water will not be trapped between the snow berms and flow down the road.
(14) Materials which slough or slump onto the road bed or into the roadside drainage ditch before the licensee completes the exploration project must be disposed of on the road bed or on the fill material in a manner that will not obstruct any of the drainage facilities previously described.
(15) All fill and cut slopes, with the exception of rock faces, must be seeded or planted or both during the first appropriate season following construction of the road.
(16) The department may waive any of the criteria in this section if the applicant proposes methods or technologies that achieve the same or better environmental protection than that expected under the given criteria.