No change of flow characteristics of springs, streams, watercourses, culverts or drainage ditches, or alteration to wetlands or the designated floodplain and floodway, will be permitted unless approved by the Village Engineer and such approval be in accordance with Village ordinances relating to the floodplain or mandates of other regulating agencies having preeminent authority.
(a) Springs. All springs will be capped and piped in a minimum 6-inch diameter perforated pipe encased in washed gravel and connected into the nearest storm manhole or curb inlet.
(b) Easements Required. All features or facilities, both natural and man made, such as culverts, drainage ditches, storm sewers, streams or watercourses that facilitate the downstream flow of water from a watershed will be placed in an easement. Such maintenance easements will be not less than twenty (20) feet in width, measured horizontally from the top of the bank exclusive of the width of the ditch, channel or other system, and will be provided on each side of the ditch, channel or other system. Maintenance easements are to be kept free of obstructions. Detailed provisions regarding the entities to be responsible for maintenance of the facility will be submitted in text form with the subdivision plat. As applicable, notes regarding maintenance will be made on the plat.
(c) Culverts. All multiple culvert installations, or culverts larger than twelve (12) inches will have concrete headwalls.
(d) Underground System Required. Where it has been determined that the anticipated critical storm flow for the drainage of a watershed or modified watershed area could be borne by a storm culvert or storm sewer system sixty (60) inches or less in diameter, such flow will be placed underground in an approved storm culvert or storm sewer system unless otherwise approved by the Village Administrator, Village Engineer, and Community Development Coordinator.
(e) Adjacent Open Ditches. Where ditches or watercourses that are presently open are contained in public easements that border proposed developments, the Village Engineer may require the installation of an underground storm sewer system to replace the open ditch.
(f) Minimum Slope. The minimums side slope for open retention or detention basins or open ditches will be three (3) to one (1) or as required for ease of maintenance.
(Ord. 19-20. Passed 11-4-20.)