Credits may be authorized up to 20 percent when stormwater best management practices are incorporated into the landscape plan, subject to the approval of the Director of Utilities. Such practices shall adhere to recognized principles of stormwater drainage engineering. The list of best management practices (BMPs) available for credits and their potential credit is set forth in the City of Topeka stormwater BMP design handbook. (Ord. 20262 § 28, 10-6-20.)