A. All stormwater runoff shall be subject to review and approval by the city with regard to analysis, design and construction of drainage facilities. The appropriate public authority shall have the right to maintain, or cause to be maintained, the drainage system for its intended purposes. If a basin master drainage plan is adopted for the area under consideration, then the provisions of the plan shall be adhered to unless amended.
B. The stormwater drainage system, both public and private, may consist of: 1) roadways, storm sewers, detention facilities, retention facilities, improved channels; 2) unimproved drainageways left in their natural condition; 3) the areas covered by drainageway easements for the purpose of providing overland flow; and 4) all appurtenances to the above including inlets, manholes, junction boxes, head walls, dissipaters, culverts, etc. All portions of the drainage system that exist on or in dedicated street rights of way or property owned by the city in fee shall be owned and maintained by the city, unless provided otherwise by agreement or covenant. Improved and natural channels on private property shall be maintained by the property owners. In this context, the removal of dead or dying trees or storm debris shall not be considered to alter the channel so as to make it no longer a natural channel.
C. Every development shall be provided with a stormwater drainage system designed by an engineer registered in the state of Oklahoma, adequate to serve the development, and otherwise shall meet the approval requirements of the officials having jurisdiction.
D. The stormwater drainage system shall be designed so that property owners located downstream from and upstream from the development shall not be injuriously affected by the construction, operation, or maintenance of such system.
E. The stormwater drainage system plans prepared and sealed by a professional engineer shall show both plan and profile views of the proposed improvements. Any manhole or access point to the system that is buried out of sight shall be dimensioned to permanent objects in the vicinity.
F. The stormwater drainage system shall be designed to receive and pass the runoff from a one percent (1%) chance storm under ultimate urbanization. In areas covered by the regulatory flood area, that data shall govern. In areas not covered by the regulatory flood area, the design engineer shall prepare and submit a study for the area. The ultimate urbanized flow shall be confined within the said stormwater drainage system.
G. A minimum of the ten percent (10%) chance and one percent (1%) chance storms shall be evaluated when designing the stormwater drainage systems. (Ord. 1969, 2011)