ARSD 74:02:08:07.01. Category 3 spillway design flood exception

For small size category 3 dams with an emergency spillway, the minimum spillway design flood is a 25-year frequency if the product of the intermediate storage capacity times the effective height is less than 3000. For small size category 3 dams without an emergency spillway, the spillway design flood is a 25-year frequency if the product of the maximum storage capacity times the effective height is less than 3000.