(A) Grading and building pad elevations.
(1) Maximum yard slopes are 3:1 where soil has been disturbed during construction processes. Top of foundation must be no less than 6 inches above finished grade and a minimum of 15 inches above an adjacent road elevation unless a written variance is granted by either the city engineer.
(2) For all structures located in the SFHA as shown on the FEMA maps, the lowest floor elevations of all residential, commercial or industrial buildings, shall be so that all floors, including basement, shall be at the flood protection grade and therefore have 2 feet of freeboard above the 100-year flood elevation.
(3) The low entry elevation for residential buildings outside the 100-year floodplain shall have 2 feet of freeboard above the 100-year under proposed conditions.
(B) Subsurface drain tile for subdivisions.
(1) All residential subdivisions shall require a perforated subsurface drain tile system in addition to the storm sewer system for the purpose of lowering the water table. Drain tiles shall be no less than 8 inches in diameter. All lots will have a subsurface drain tile on the lot or within adjoining easements to serve the lot. The preferred location of all subsurface drain tile is to be near the proposed area that the septic system will be located, if septic systems are used.
(2) Subsurface inlets will be periodically located on the subsurface drain tile line for inspection purposes only in order to locate any problem areas that may occur. The subsurface drain tile system may be tied into the storm sewer system, but must be accounted for in the storm sewer calculations. The subsurface drain tile cannot be used for stormwater storage. All lines must have a positive flow above the hydraulic grade line of main line sewers and detention basins. The size of the subsurface drainage tile shall not be any less than:
Number of Lots Allowed per Pipe Size
|
Tile or Pipe Diameter | |
N-Value=0.010 | N-Value=0.017 | (Inches) |
1-10 | 1-5 | 8 |
11-17 | 6-11 | 10 |
17-28 | 12-17 | 12 |
(C) Structures near regulated drains. For regulated drains not located in platted subdivisions, unless otherwise approved by the city engineer, no permanent structure shall be erected within 75 feet measured at right angles from:
(1) The existing top edge of each bank of a regulated open drain, as determined by the city engineer; or
(2) The center line of a tiled regulated drain.
(Ord. 01-2000, passed 7-18-2000)