1. Review available mapping, reports, prior designs, etc. Information includes, but is not limited to, LiDAR contours from state sources available through MetroCOG, storm drainage record map with PS shown, Townwide Master Drainage study from 2001, draft South End Drainage study from 2024. Meet with Highway and Building Maintenance Departments to review the station in the field and discuss on-going maintenance concerns. 2. Perform hydrologic and hydraulic study of existing and proposed conditions in order to determine the most efficient solution to making the pump station perform more effectively to mitigate flooding. The design criteria are to limit flooding from a 10 year storm from entering any residential structures and for the road to be passible by emergency vehicles. Evaluate and report on capacity of stormwater collection and pumping for five, 10 and 25 year rainfall events. x Determine costs and benefits of extending the forcemain further down South Avenue to prevent short circuiting of the gravity line as discussed in the Master Drainage study. Consider the effects of future sea-level rise in the analysis. x Determine the layout, costs and benefits for providing 40,000 cubic feet of offsetting stormwater detention storage, also considering MS4 benefits for complying with the Town’s DCIA reduction goal. The Town may consider purchasing of flood prone property as open space, which could possibly be used for stormwater storage. x Determine the layout, costs and benefits of installing a backup generator for the station. Alternatively, ensure there is adequate space and facility appurtenances to accommodate a portable generator in times of emergency.
