Chapter 17.15
DRAINAGE PLANNING
Sections:
17.15.020 Drainage right-of-way.
17.15.010 General.
Storm water shall be conveyed through a subdivision in a manner that will not damage development within the subdivision nor create an undue nuisance to the inhabitants thereof or adjacent properties. When improvements within a subdivision change the natural flow of storm drainage, they shall be designed in a manner that will not damage the land or change the flow characteristics of the natural drainage over the land upstream or downstream from the subdivision unless the subdivider provides the town with a hold-harmless agreement from the affected upstream or downstream property owners. (Ord. 06-07 § 1, 2006; prior code § 13-1-6(A))
17.15.020 Drainage right-of-way.
All concentrated storm drainage that cannot be conveyed in a public street right-of-way shall be conveyed in a dedicated drainage way or in a drainage easement. Dedicated drainage ways shall be vested in the public for public use and not included in any lot. Drainage easements that are not dedicated for public use but for construction and maintenance of drainage facilities shall be granted to the public, and they may be included in a lot but the use thereof shall be restricted to uses that will not interfere with maintenance of the natural flow of storm drainage over and/or under the easement. A drainage easement shall be provided to accommodate the flow that is expected to occur at least once every 100 years. A dedicated drainage way shall be provided to accommodate the flow that is expected to occur at least once every 25 years; provided, however, that this requirement may be waived by the commission when the resulting drainage way will be less than 10 feet in width and less than one foot in depth. All drainage easements shall be at least 15 feet in width. (Ord. 06-07 § 1, 2006; prior code § 13-1-6(B))
17.15.030 Hydrologic reports.
When required, will describe as a minimum: drainage points of concentration, calculated peak drainages, a composite basin runoff analysis, cross-sectional location and modes of flow conveyance, slopes, velocities and other information as necessary to complete the analysis. (Ord. 06-07 § 1, 2006; prior code § 13-1-6(C))