Stormwater Control Measure Rehabilitation
McAdams was contracted by Chancery Village maintenance to design and develop rehabilitation drawings for deficiencies in three of the stormwater control measures (SCM) currently on-site. The SCM being addressed are a bioretention cell, which drains to a wetland and subsequently a level spreader, all providing treatment in series. In working with the Town of Cary and reassessing current regulations, McAdams was able to propose decommissioning of the level spreader and replace this discharge location to simplify maintenance. Minor modifications to the wetland are proposed, as well as coordination with the client’s structural engineer to rehabilitate the stone cell and the wetland. Rehabilitation to the bioretention cell is more intrusive and involves selective clearing and thinning of compacting vegetation; installation of a new riser and spillway system; and restoring infiltration capacity to the SCM. This is to be performed with the SCM still online and while not disturbing the already present outlet works of both the wetland and bioretention cell. This upgraded system will utilize the new outlet structure in order to increase functionality and longevity of the existing bioretention cell and wetland system and the ability to accept larger storms.