1. (a) When the panel drip edges are more than 75 degrees from parallel to the post-construction land contour lines, channel design calculations in accordance with the National Engineering Handbook, Part 654 Stream Restoration Design, Chapter 8 Threshold Channel Design, August 2007, available as noted in Appendix B, shall be submitted when:

   1. (1) Flow paths exceed 300 feet for slopes of 8% or greater, but less than 15%; and
   2. (2) Flow paths exceed 100 feet for slopes greater than 15%.
2. (b) The plans shall show protective lining of concentrated flow paths as necessary when calculated velocities exceed the velocities for a vegetated surface, as determined with the reference in (a), above.

Source. #13758, eff 9-28-23; ss by #14472, eff 1-19-26, EXPIRES: 1-19-36 (formerly Env-Wq 1511.07)