Swale Detail.pdf

This file contains a technical specification detail for a dry swale stormwater management system prepared for the Town of Marlborough, Connecticut. The document presents engineering specifications and design parameters for a stormwater drainage feature, including materials, dimensions, and installation requirements. The dry swale is designed with a maximum ponding depth of 36 inches during a 10-year storm event, reducing to 12 inches at the longitudinal midpoint and 18 inches at the downstream end. The specification requires non-woven filter fabric compliant with Connecticut Department of Transportation Standard Specifications M.08.01.19 (Drainage - Geotextiles), native grass or plants as preferred vegetation with alternative provisions for river stone or smooth crushed stone, 2:1 side slopes, and a 30-linear-foot perforated 6-inch HDPE underdrain sloped north to south at 5 percent gradient. The system includes 2-3 inch crushed stone supplemented with 1/2-inch drainage stone, with non-woven filter fabric applied to the sides of excavation only, and requires a minimum 24-inch separation to the seasonal high water table or bedrock.

The specification establishes detailed material and construction standards for stormwater management infrastructure but does not contain pricing information, set-asides, bidding requirements, or contract terms. This technical document appears to be a supporting exhibit or design specification that would accompany a larger construction or site development project for the Town of Marlborough, Connecticut, and would serve as reference material for contractors bidding on projects involving stormwater management systems.