(a) A storm drainage system adequate to serve the needs of the proposed new streets or the entire subdivision shall normally be required in new subdivisions. When a public storm sewer main is available at the plat boundary or within 1,000 feet, the subdivider shall construct a storm sewer system and connect with such storm sewer main.
(b) In areas where a public storm sewer main is not available, the developer shall take necessary steps to prevent storm drainage onto adjacent properties and in accordance with the natural drainage pattern of the land.
(c) Storm sewers shall be located within a street right of way or utility easement in a manner approved by the Planning Commission.
(d) Bridges or culverts shall be designed to support and carry loads according to the judgment of the City Engineer and be constructed the full width of the cartway plus additional length as deemed necessary by the City Engineer to satisfy local drainage patterns.
(e) Where open watercourses are planned, adequate safety, erosion control, drainage (stagnant water), protection of capacity and appearance measures shall be taken by the subdivider to insure proper, safe, healthful disposal of storm water.
(f) Minimum grade of drainage courses shall be designed to create a cleaning effect (velocity of five feet per second) except that a minimum cleaning effect (velocity of three feet per second) may be permitted by the City Engineer where greater grade cannot be achieved.
(g) At intersecting streets water in gutters and ditches shall be placed in adequate culverts.
(h) Location of storm sewers shall be in accordance with existing systems or in accordance with regulations suitable to the City Engineer.
(i) Storm sewers shall have a minimum diameter of twelve inches and a minimum grade of one-half of one percent (.50%)
(j) Manholes shall normally be spaced 300 feet apart where pipe sizes of twenty-four inches or less are used and not over 450 feet where larger sizes are installed. Manholes shall also be installed at all grade changes, street alignment changes and pipe size changes. Inlets may, if approved by the City Engineer, be substituted for manholes.
(k) Special sections of ten to fifteen feet radii shall be installed where abrupt changes in direction are made.
(l) Reinforced concrete or corrugated metal pipe shall normally be required under driveways and shall not be less than twelve inches in diameter and twenty feet in length. Reinforced concrete or corrugated metal pipe may also be used and shall be laid so as to maintain the flow line of the open ditch.
(m) All phases of construction of open ditches, gutters or storm sewers including width, depth, shapes, erosion control, minimum grade, size and area shall be in accordance with the requirements of these regulations and all storm drainage facilities shall be inspected and certified by the City Engineer prior to being covered.
(4-24-72)