A. It is the intent and purpose of this chapter that the primary component of drainage systems shall be natural channels within drainage easement or rights of way. Streets, alleys and enclosed conduits shall principally serve and be designed to carry stormwater to natural channels in accordance with the provisions of this chapter:
1. Open Channels: Natural drainage channels and techniques shall be given priority consideration in preparation of drainage system designs and shall be designed or improved as an integral part of the landscape:
a. The design of any development should provide for the maximum practical use of open channels and natural streams;
b. Drainage channel improvements shall be designed to preserve and protect large trees and other worthy botanical and geological features to the greatest possible extent; and
c. Wherever channel improvements are required to accommodate calculated flows in a specified manner, the designs shall provide maximum utilization of turf, sodding and other natural drainage techniques;
2. Storm Sewers: Closed, underground drainage conduits should be employed as appropriate to meet site or geographic conditions or to meet the requirements of this chapter and all specifications and performance standards pertaining thereto;
3. Streets And Alleys: Stormwater runoff into or within a street or alley shall be permitted provided the developer fully and adequately demonstrates that the street or alley or any improvement thereof will provide drainage in full conformance with all other provisions of this chapter and will prevent runoff or overflow into adjacent or nearby property beyond the capacity of the existing or proposed drainage system;
4. Erosion Control: All persons engaged in land development or modifications shall prevent the erosion of soil and movement of sedimentation into, onto or through streets, gutters, catch basins, culverts or other drainage channels and shall prevent erosion as a result of flows from streets, gutters, culverts or other drainage system components:
a. Where it can be demonstrated that there is no alternative to rapid runoff water because of identifiable restrictions, the developer shall be required to provide measures to prevent erosion, damage, flooding or other adverse effects; and
b. The city may require the cleaning, straightening or repair of any natural drainage channel or natural features of other drainage channels when necessary to provide for the free flow of water or to eliminate or prevent erosion upstream and downstream. (Ord. 1387, 1-30-1996)