a. Piping Requirements. All corrugated steel and aluminum pipe intended for use within the roadway shall be of the gauge recommended by the manufacturer and approved by the Engineering Department for the cover and service conditions required. Corrugated steel and aluminum pipe shall be bituminous coated where required by the Engineering Department. Additional protective coating or paving of metal pipes may be required for severe service conditions. The gauge of pipe proposed at each location shall be noted on the improvement plans.
b. Storm Drain Inlets. Storm drain inlets shall be of a design approved by the Engineering Department. Water shall be directed into the storm drain inlet without a reversal of direction of the flow of the water.
c. Drainage Structures to Allow for Tidal Action and Flood Stage. Drainage structures shall allow for tidal action and flood stage where applicable. The hydraulic pressure elevation in any storm drainage system shall be at least one and twenty-five-hundredths (1.25') feet below the top of any inlet grate or manhole.