Anne: Rain gardens and their fancier cousins, bioretention cells, are popping up all over the urban landscape. But how well do they work? Engineers have done an excellent job designing and testing them at the site scale, but few studies have been able to test their effectiveness at larger scales. What happens when a bunch of rain gardens and bioretention cells are added to a neighborhood? Do they make a significant difference in the stormwater runoff entering the local stream? Thanks to a brilliant study design by Cleveland Metroparks, Anne and graduate student Kimm Jarden were able to answer this question with a resounding “Yes, but…” Their paired watershed study showed that the green infrastructure retrofits can very effective at reducing peak and total stormflow, but that seemingly small differences in design and construction can have big ramifications for performance at the neighborhood scale.
This research was highlighted in a press release issued by Kent State in mid-November and was featured in several local news articles.
Figure 4 from Jarden, K.M., Jefferson, A., and Grieser, J.M. 2015. Assessing the effects of catchment-scale green infrastructure retrofits on hydrograph characteristics. Hydrological Processes, online ahead of print. doi: 10.1002/hyp.10736.