R655-13-7. Specific Stream Alteration Activities

  (1) The following subsections address specific types of stream alteration activities and the nature of special information that shall be provided to the state engineer. These subsections are not intended to be comprehensive and other requirements may be imposed at the discretion of the state engineer. All requirements may be waived at the discretion of the state engineer.

  (a) Applications that propose to install a utility (sewer, water, fiber-optic cable, etc.) beneath a natural stream will be subject to the following conditions and requirements:

  (i) The top of the utility shall be a minimum of three (3) feet below the existing natural elevation of the bed. In some instances, a greater depth may be required if there is significant evidence of on-going erosion.

  (ii) Where utility crossings occur on river bends or areas of significant on-going bank erosion, the utility shall be kept at an elevation below that of the bed of the stream, laterally away from the stream, to a distance where erosion will not expose the utility at a later date.

  (b) Applications that propose to span natural streams by way of bridges or other structures will be subject to the following conditions and requirements:

  (i) Clearance of the lowest part of the span shall be a minimum of three (3) feet above bankfull stage unless specifically exempted by the state engineer.

  (c) Applications that propose installation of a culvert or other similar structure will be subject to the following conditions and requirements:

  (i) The bottom of the culvert should contain natural bed material. This may require installing the culvert flowline below the bed of the channel or installation of an open bottom culvert.

  (ii) Bedding and backfill placed around the culvert shall not be more free-draining than the adjacent bed and bank materials and shall be compacted to in-place densities at least as great as those of similar adjacent materials.

  (iii) The culvert design should include energy dissipation structures or devices when necessary.

  (d) Woody debris within the jurisdictional limits established in R655-13-5 may be removed without written authorization by the state engineer provided that removal can be accomplished by way of manual methods or through use of equipment located outside the channel.

  (e) Applications that propose to relocate a natural stream channel will be considered if:

  (i) the existing channel is degraded or impaired and relocating the channel will enhance the natural stream environment; or

  (ii) the existing channel location represents a significant hazard to existing permanent structures, residential areas, transportation routes, or established utilities; and other bank stabilization methods can be shown to be inappropriate or infeasible for reducing or eliminating the hazard.

  (iii) Detailed drawings of the new channel (plan, cross-section(s), and profile views) and vegetation plans for the channel and surrounding area accompany the application.

  (iv) Monitoring and reporting plan for planted vegetation is submitted.

  (f) Applications that propose to remove beaver dams will be considered if:

  (i) the dam(s) interferes with the operation or maintenance or threaten the integrity of a bridge, culvert, an authorized man-made dam, or authorized water diversion works; or

  (ii) the presence of the dam(s) causes or may reasonably be expected to cause flooding of pre-existing developed areas, buildings, transportation routes, or established utilities; or

  (iii) the dam(s) exists in areas of highly erosive soil or recently authorized stream restoration activities; or

  (iv) the presence of the dam(s) represents a detriment to fish management.

  (v) Removal of established beaver dams for the sole purpose of obtaining impounded water to supplement other water sources may not be approved on that basis alone.