Problem: Green infrastructure, like gray infrastructure, has a designed drainage time. When the system experiences a failure, water may accumulate and fail to drain at the BMP’s low point. This can lead to clogging of outlet structures and mosquito breeding. While vegetation can reduce this problem from gray infrastructure conditions, failures elsewhere in the system can oversaturate soils and cause vegetation loss.
Solution: Standing water can be avoided through proper construction, regular inspection, and prompt repair. Unanticipated low points in the design can be rectified through regrading of the BMP. During the design process, plans should be evaluated to ensure that slopes are sufficient to convey water. Overflow devices and outlet controls should be inspected after storms exceeding one inch in rainfall and at least four times annually for clogging that may prevent water from leaving the system. The NJDEP recommends bi-weekly inspections during vegetation establishment/restoration and a minimum of one inspection during the growing season and one during the non-growing season for established vegetation.