A. 
Storm drainage systems shall be designed by a licensed professional engineer using prudent methods and the most recent information available.
B. 
Two sets of drainage system calculations shall be submitted for review and record to the Subdivision Administrator. These calculations shall include the following:
(1) 
Design storm information.
(2) 
Drainage basin area.
(3) 
Development extent.
(4) 
Pipe flow calculations.
C. 
Extensive consideration shall be given to retention and detention features in design, and, whenever possible, the outfall of the system shall be in the same basin as the system.
A. 
Storm drainage systems shall be designed to handle any future development of the basin in which it is situated. A culvert or other drainage facility shall, in each case, be large enough to accommodate potential runoff from its entire upstream drainage area, whether inside or outside the subdivision. The Subdivision Administrator shall review the design and size of the facility based on anticipated runoff from a ten-year storm under conditions of total potential development permitted by watershed.
B. 
The subdivider's engineer shall also study the effect of subdivision on the existing downstream drainage facilities outside the area of the subdivision. This study shall be reviewed by the Subdivision Administrator. Where it is anticipated that the additional runoff incident to the development of the subdivision will overload an existing downstream drainage facility during a five-year storm, the Planning Board shall notify the Town Board of such potential condition. In such case, the Planning Board shall not approve the subdivision until provision has been made for the improvement of said condition.