A. The primary objective of drainage design is protection of village streets and property while minimizing the possible flood damage to surrounding properties and structures. It should be emphasized that good drainage is one of the most important factors in street design. It preserves the appearance as well as the level of service of the street while minimizing maintenance costs. Water flowing in a roadside ditch shall be diverted away from the street as quickly as possible. In no case shall water travel in a roadside ditch for a distance greater than two thousand feet (2,000') or have a flow greater than ten (10) cubic feet per second with the occurrence of a 50-year, 24-hour frequency storm.
B. All drainage installations shall be designed to permit free, unobstructed passage of debris and silt or provide for their deflection and/or collection at a point upstream that will not create an expensive maintenance problem. Settlement basins shall be provided when a silting problem may exist downstream. Modification of natural channels or transferring runoff from one basin to another is not permitted except where no reasonable alternative exists and where the proposal has been reviewed and approved by the village public works director.
C. A recurring problem on village of Angel Fire streets is ice buildup. Drainage design shall anticipate areas of potential ice buildup.
D. The following criteria must be observed as minimums in street drainage design:
1. Nuisance flows will not be conveyed across arterial or collector streets on the surface by valley gutters or other means.
2. The use of quarter point crown (i.e., high point of crown at mid lane on high side of street) is preferred over the use of full side hill street configuration to prevent sheet flow across pavement surfaces.
3. Transitional pavement surface approaches to intersections must be designed to contain nuisance flows within gutter lines; valley gutters must be provided to accommodate flows across intersection suitably, parallel to the major traffic carrying street. (Ord. 2007-06, 8-14-2007)