Section Env-Wt 904.09 - Repair, Rehabilitation, or Replacement of Tier 3 and Tier 4 Existing Legal Crossings(a) The repair, rehabilitation, or replacement of tier 3 stream crossings shall be limited to existing legal crossings where the tier classification is based only on the size of the contributing watershed.(b) Rehabilitation of a culvert or other closed-bottom stream crossing structure pursuant to this section may be accomplished by concrete repair, slip lining, cured-in place lining, or concrete invert lining, or any combination thereof, except that slip lining shall not occur more than once.(c) A project shall qualify under this section only if a professional engineer certifies, and provides supporting analyses to show, that:(1) The existing crossing does not have a history of causing or contributing to flooding that damages the crossing or other human infrastructure or protected species habitat; and(2) The proposed stream crossing will:a. Meet the general criteria specified in Env-Wt 904.01;b. Maintain or enhance the hydraulic capacity of the stream crossing;c. Maintain or enhance the capacity of the crossing to accommodate aquatic organism passage;d. Maintain or enhance the connectivity of the stream reaches upstream or downstream of the crossing; ande. Not cause or contribute to the increase in the frequency of flooding or overtopping of the banks upstream or downstream of the crossing.(d) Repair, rehabilitation, or replacement of a tier 4 stream crossing shall comply with Env-Wt 904.07(d).N.H. Code Admin. R. Env-Wt 904.09
Amended by Volume XXXVIII Number 32, Filed August 9, 2018, Proposed by #12578, Effective 7/21/2018, Expires 7/21/2028.Amended by Volume XXXIX Number 28, Filed July 11, 2019, Proposed by #12809, Effective 12/15/2019, Expires 12/15/2029.