(a) System Required.
(1) Every subdivision and land development shall be provided with a comprehensive Storm Water Management System which is adequate to serve the area and meets the requirements of this chapter, the Storm Water Management and Sediment Control Design Manual, and other criteria of the City. Two separate and distinct drainage systems exist:
A. A minor drainage system for collecting and transporting runoff from frequently occurring storms. It includes watercourses, streets, curbs and gutters, and underground storm sewers, manholes, catch basins, and culverts. This system's purpose is to lessen or eliminate inconveniences and safety and health hazards associated with frequent storms. Except where indicated otherwise, design criteria and requirements of this chapter are directed to the minor drainage system.
B. A major drainage system that transports storm water runoff which exceeds the capacity of the minor drainage system along a route either man made or natural.
(b) Storm Water Runoff Control/Water Quantity.
(1) Developers are required to design improvements such that after development, the rate of storm water runoff leaving the project area at strategic points is not more than if the project area had remained undeveloped. If necessary, detention/retention facilities shall be constructed to assure that this requirement is met.
(2) Where a portion of the project area contains existing development features such as buildings, streets, parking lots, sidewalks, etc., and a permit application is made for additional development, the area to be considered in determining the rate of storm water runoff shall be only that on which the additional development is sought.
(3) The City Engineer may reduce or waive requirements for an individual detention/retention basin if a common or regional basin of adequate design is available or if the Utility is reasonably certain one will be constructed and if the major drainage system from the project area to such common or regional basin is such that the public health, safety, and welfare will not be in jeopardy.
If this option is exercised, the developer will provide the City with a fee-in-lieu of building the required storm water management BMP.
(4) Storm water management systems will be designed for the ultimate use of the land and shall be capable of conveying upstream runoff as determined by the City Engineer.
(c) Easements and Underdrains. Where a storm sewer, culvert, open channel, catch basin, inlet, manhole or other drainage structure lies outside the public right-of-way, easements of sufficient size as determined by the City Engineer may be provided to assure access and maintenance. (Ord. 2003-07. Passed 1-28-03.)