As of June 29, 2022, this project has not yet been awarded. A timeline for award has not yet been established. The City of Roslyn (City) is con-tracting for a high-flow bypass storm water pipe running along Coal Mines Trail to alleviate capacity concerns within the City storm drain system between East Pennsylvania Avenue and East Washington Avenue as identified in the City of Roslyn Stormwater Comprehensive Plan, July 2014, Gray & Osborne, Inc. (SCP). This bypass will route excess flows directly to Crystal Creek, begin-ning at East Washington Avenue and following the Coal Mines Trail eastward and then south-eastward for approximately 1,660 feet. The undersized pipe in the existing trunk line will remain in place, conveying all low-flows and baseflows along the original route. The proposed bypass begins with a 7' x 9,5' x 14.5' cast-in-place concrete box structure with springoassisted access hatch. The bypass structure contains an overflow weir that diverts high flows into a 36" HOPE pipe that. travels 412' in length before tran-sitioning to a 42" HOPE pipe for 1,286. This pipe outfalls into a proposed ditch that has riprap lin-ing for 23', then streambed cobble mix for 30' before Walling into Crystal Creek. A small portion of the existing stream bank will be re-graded to provide an appropri-ate transition! between the outfall ditch and Crystal Creek. The proj-ect also includes interception of an 8" storm drain where it intersects the bypass alignment., paving, replacement of gravel pathway. along the pipe alignment., plant-ings, and :installation of a split-rail fence and hand-placed boul-ders separating the existing path from the outfall ditch. The method of contractor selection has not been determined at this time.
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