(A)   Culverts, pipes, and trenches.
      (1)    The diameter of all culverts shall be determined by the county using history and run-off data available at the USDA Soil and Conservation Service. No culvert less than 18 inches in diameter will be acceptable. The length of the culvert will be determined by the height of the fill, but shall be of sufficient length to provide a minimum 22-foot wide finished roadbed.
      (2)   All concrete culverts shall conform to AASHTO M170 state requirements and only steel reinforced culvert will be acceptable.
      (3)   All pipe shall be laid in a trench in all cases where possible. Trenches shall be excavated to the required grade and to a width sufficient to allow for proper joining of the pipe and compaction of the backfill under and around the pipe. The trench bottom shall be shaped to fit the bottom of the pipe and shall have recesses shaped to fit any projected hubs or bells. All culverts shall have a minimum of 12 inches fill above the top of the culvert, excluding pavement or its base.
   (B)   Storm drains; catch basins. Catch basins shall be required to receive surface water from road side gutters or swales into piped or open ditch drains. Standard manholes and covers, inside step and gutter gratings may be required for some installations. The Public Works Director will direct the application if applicable. All curves shall be designed to pass the peak rate of run-off from at least a 25-year rain fall return frequency for a 1-hour storm.
(Ord. 124, passed 9-17-1991; Am. Ord. passed 2-5-1997; Am. Ord. passed 11-5-1997; Am. Ord. passed 1-5-2000; Am. Ord. 07-37-03, passed 7-2-2003)