Green Stormwater Infrastructures (GSIs) are typically built for multi-purposes: stormwater treatment and green space. Established mature vegetation is designed to achieve the desired results. However, plants often fail before established. Frequent replacement of dead plants become a standard operation. The main reason is that plants undergo constant stresses: either too wet or too dry. By design, GSIs are flooded during storms. Also by design, the growth media drain water out quickly between rain events to make room for next storm and to prevent the waterlogging problems. To accomplish this, very porous growth media are used. As a result, soil moisture changes quickly from soaking wet to bone-dry in short period. The extreme variations in soil moisture makes it hard for any plants to survive. By looking at the fundamental aspect of this situation, the main cause of the problems is the limited plant available water (PAW) in the porous growth media. This presentation will review novel technologies that can address this problem by significantly increasing PAW and by using some of the abundant stormwater in GSIs. By capturing the stormwater, it further enhances the stormwater reduction and retention features of GSIs. In between storms, the stored stormwater will help the survival and thrival of the plants so they can do their jobs.
There other stresses on the GSI. For example, salt is a common one for northern climates (from road salt) and coastal areas with seawater intrusion and coastal flooding. We will also discuss the potential solutions to these stresses.
