(a) A buffer for a stream system shall consist of a strip of land extending along both sides of a stream and its adjacent wetlands or slopes.

(b) The streamside area portion of the buffer shall begin at the edge of the waterway for type I and at the centerline of the channel for type II and type III streams. The edge of the waterway is the outer wet edge of the channel during base flow or where the edge of vegetation occurs. The buffer shall be composed of two distinct areas: streamside area and outer area. The outer area widths are defined by the GIS-based stream buffer shapefile for the City of Topeka. The GIS-based stream buffer shapefile is located on the City’s utilities exploration map. As an alternative to using the GIS-based stream buffer shapefile for the outer area extent, an analysis may be done using the procedure outlined in Section 5605.5, Stream Assessment of the Kansas City Metropolitan Chapter of the American Public Works Association’s Standard Specifications and Design Criteria (APWA); Section 5600, Storm Drainage Systems and Facilities, to justify use of a different outer area extent. A rating of 12 or below when using the channel condition scoring matrix is considered acceptable. A rating between 12 and 18 may be acceptable if engineering justification is provided to verify adequate protection of the channel. A rating greater than 18 does not support a change from the GIS-based stream buffer. The streamside area widths are defined in the following table. Each area has allowable uses and vegetative targets as follows:

(c) The width for all buffers (i.e., the base width) is subject to an expansion requirement depending on wetlands or critical areas.

(d) Water Pollution Hazards. The following land uses and/or activities are designated as potential water pollution hazards and must be set back from any stream or water body by the distance indicated below: