N.H. Admin. Code § Env-Wq 1508.20

Current through Register No. 44, October 31, 2024
Section Env-Wq 1508.20 - Stormwater Control and Conveyance Practices: Conveyance Swales

Conveyance swales shall comply with the following:

(a) Swales shall not be used in groundwater protection areas where the stormwater comes from one or more high-load areas, unless the practice has an impermeable liner;
(b) The side slopes shall be designed to convey non-erosive velocities; and
(c) The swale shall be sized to convey the 50-year, 24-hour storm.

N.H. Admin. Code § Env-Wq 1508.20

Derived From Volume XXXVII Number 32, Filed August 10, 2017, Proposed by #12342, Effective 8/15/2017, Expires 8/15/2027.
Amended by Number 41, Filed October 12, 2023, Proposed by #13758, Effective 9/28/2023, Expires 9/28/2033 (formerly Env-Wq 1508.19) (see Revision Note #4 at chapter heading for Env-Wq 1500).