Wis. Admin. Code Department of Natural Resources NR 151.243

Current through September 30, 2024
Section NR 151.243 - 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.

Table 2. Maximum Pre-Development Runoff Curve Numbers

Runoff Curve Number

Hydrologic Soil Group

A

B

C

D

Woodland

30

55

70

77

Grassland

39

61

71

78

Cropland

55

69

78

83

Note: Where the pre-development condition is a combination of woodland, grassland, or cropland, the runoff curve number should be pro-rated by area.

(2) EXEMPTIONS. This section does not apply to the following:
(a) A transportation facility 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 151.241(4), a transportation facility that is part of a redevelopment project.
(c) Except as provided under s. NR 151.241(4), a highway reconstruction site.

Wis. Admin. Code Department of Natural Resources NR 151.243

CR 09-112: cr. Register December 2010 No. 660, eff. 1-1-11.

The intent of s. NR 151.243 is to minimize streambank and shoreline erosion under bank-full conditions.