1. (a) To determine the minimum required detention storage, the applicant shall show that the computed runoff from the detention storm can be stored in the reservoir and discharged through the primary spillway without any flow being discharged through the auxiliary spillway. The elevation of the auxiliary spillway control section shall be set so that the computed runoff from the detention storm specified in the following table and determined from the procedures in K.A.R. 5-40-30 through K.A.R. 5-40-33 does not result in discharge through the auxiliary spillway.

   Hazard class	Size	Purpose	Minimum detention storm
   A	1, 2	Flood control	4% chance
   A	3	Flood control	4% chance
   A	4	Flood control	2% chance
   Hazard class	Size	Purpose	Minimum detention storm
   B	All	Flood control	2% chance
   C	All	Flood control	2% chance
   A	1, 2	All uses other than flood control	50% chance
   A	3	All uses other than flood control	50% chance
   A	4	All uses other than flood control	20% chance
   B	All	All uses other than flood control	20% chance
   C	All	All uses other than flood control	20% chance

   Each dam that has flood control as a purpose shall meet the detention storm requirements for a flood control structure. A dam that is not constructed for flood control purposes and whose auxiliary spillway meets the requirements for a service spillway in K.A.R. 5-40-57 shall not be required to meet any minimum detention storm requirement in the table in this subsection.

2. (b) Each dam shall have a primary spillway and an auxiliary spillway, unless a service spillway meeting the requirements of K.A.R. 5-40-57 is provided.

(Authorized by and implementing K.S.A. 2006 Supp. 82a-303a; effective May 18, 2007.)