Peak discharge performance standard

Peak discharge performance standard. (1) Requirement. By design, BMPs shall be employed to maintain or reduce the 1-year, 24-hour and the 2-year, 24-hour post-construction peak runoff discharge rates to the 1-year, 24-hour and the 2-year, 24-hour pre-development peak runoff discharge rates respectively, or to the maximum extent practicable. The runoff curve numbers in Table 2. shall be used to represent the actual pre-development condition. (2) Exemptions. This section does not apply to the following: (a) A post-construction site where the discharge is directly into a lake over 5,000 acres or a stream or river segment draining more than 500 square miles. (b) Except as provided under s. NR 151.121 (5) , a redevelopment post-construction site. (c) An in-fill development area of less than 5 acres.