In August of 2021, ten downspout planters were installed in the Witherspoon Jackson STAR Neighborhood with funding from a STAR mini-grant. The planters were built with support from a group of Princeton University Community Action students.
A neighborhood Stormwater Analysis prepared by The Watershed Institute in 2020 demonstrates how water rushes downhill through the barren Witherspoon Jackson neighborhood until the land flattens around Birch and Leigh Avenues, where it tends to pool, flooding yards and houses.
Downspout planters are plant boxes installed at the base of a gutter downspout. They allow stormwater from gutters to flow through and be absorbed by vegetation. The systems temporarily store runoff and filter sediment and pollutants as water infiltrates through the planter.
These systems typically consist of gravel, soil, plants, and connect to the roof downspout. They are typically waterproof, and the bottom of the planter is usually impervious, as to not infiltrate runoff into the ground. Rather, they rely on evapotranspiration and short-term storage to manage stormwater. Excess water may overflow into the existing downspout connection.
Two years following the installation, we visited the neighborhood to check on the status of the planters.
One resident and STAR Neighborhood Leader, Leighton Newlin, says the plants in his downspout planter are thriving and his yard floods less. The plants require very little to no maintenance.
A few residents commented on the beautiful flowers in the spring and how they’ve noticed much less water in their yards.
Most planters included a combination of the following native plants: blue flag irises (Iris versicolor), blue lobelia (Lobelia siphilitica), white turtlehead (Chelone glabra), Sensitive Fern (Onoclea sensibilis), Soft Rush (Juncus effusus).
These plants allow rainwater to slowly filter through the downspout planter, and it enters the groundwater cleaner. This also helps prevent erosion from fast-draining stormwater. Of course, it also beautifies the area around a downspout.
About STAR Neighborhoods
The STAR Neighborhoods program gives Princeton residents the opportunity to actively participate in building a more sustainable, together and resilient community. STAR neighborhoods select activities that will strengthen their community, reduce its carbon footprint, and inspire others to follow suit. Learn more about STAR Neighborhoods on the Sustainable Princeton website.