Unless otherwise lawfully excused from compliance with the standards set forth in this subchapter, all development to which this subchapter is applicable shall comply with the following requirements and methods for stormwater management control:
A. Stormwater, in accordance with the performance standards set forth herein, shall be directed by nonerosive means to a stormwater management system identified in the handbook of best management practices for stormwater management and erosion and sedimentation control, and the stormwater management plan criteria and engineering standards prepared for the Panhandle health district and the interagency stormwater committee by Kennedy Engineers, Spokane, WA, April 1992, or by implementation of measures shown by a design professional to have an effective design capability which equals or exceeds the standards of this subchapter.
B. All development subject to this subchapter shall be carried out such that the runoff of stormwaters shall not be accelerated or concentrated beyond predevelopment levels beyond the exterior property lines or project boundaries. Exceptions for joint management of stormwater with adjoining property owners will be allowed by the planning director if an acceptable joint agreement is presented as a part of the grading/stormwater management plan.
C. Stormwater runoff shall be managed through compliance with the design standards and best management practices, or by implementation of measures shown by a design professional to have an effective design capability which equals or exceeds the standards of this subchapter.
D. Each applicant who proposes and implements a grass covered retention area for the collection or treatment of stormwater in accordance with this subchapter shall also establish the necessary maintenance system, including an acceptable plan for sustained functioning of the collection and treatment system. (Ord. 501, 11-18-2008)