7-1-10: DRAINAGE:
When a building or parking lot is to be constructed on a lot or part of a lot that contains a natural waterway, the property owners shall be responsible for providing the necessary drainage facilities to conduct the stormwater across the property and to ensure that runoff of water, or rate thereof, from the lot will be no greater than prior to construction. The drainage facilities shall be either a properly designed grass waterway, paved ditch or a storm sewer. The facility shall be sized to carry the runoff from the entire drainage area according to the rational runoff formula Q=CiA where Q is the volume of stormwater in cubic feet per second; C is the runoff coefficient, which is that part of the rainfall rate which will contribute to the runoff rate; i is the average intensity of the rainfall in inches per hour during the time required for all parts of the watershed to contribute to runoff; and A is the area of the drainage basin in acres. Where the major portion of the drainage basin is a residential area a factor of eight-tenths (0.8) shall be used for the product of C and i. Grass waterways and paved ditches will only be permitted when the entire drainage area is within a one block area and in no case will be permitted when the drainage area extends across a street. When commercial, industrial or other large runoff areas are with the drainage area the values used for C and i shall be approved by the city engineer. The property owner shall submit plans showing size, depth, grade and location to the building official prior to issuance of a building permit. The property owner shall furnish the city an easement agreement on the form of agreement furnished by the city for the purposes of maintenance of the sewer. (Ord. 1129, 4-5-1982; amd. Ord. 1608, 8-12-1991)
The first floor elevation of the building shall be set high enough so that positive drainage away from the building in all directions can be assured.
The plat accompanying the application for building permit as required by the zoning ordinance shall indicate the proposed methods of drainage. (Ord. 1129, 4-5-1982)