A day or two ago, I was walking with my wife and grandson here in Northwest Washington DC, where I’m spending my COVID-19 time for now, and I came across this electronic gizmo on a post, with an antenna.
It is in an area that has some vegetation – almost a sort of sidewalk garden (see below). It has some sidewalk-style barriers and doesn’t look like much, but the little device with the antenna…what WAS that?
You can see where the device is mounted, on the post of the stop sign near the center of this photo.
As a project manager and a tinkerer this got my retention, er... attention. Double-time. I needed to find out what this was, and what sort of project this belonged to. It HAD to be a project, right? It was unique, it seemed temporary, and on top of it all, it seemed to be connected to some sort of sustainability initiative (it had a “RiverSmart” sticker on it).
RiverSmart is a portfolio of programs “to reduce stormwater runoff that harms the District’s waterways and the Chesapeake Bay. RiverSmart programs provide financial incentives to help District property owners install green infrastructure such as rain barrels, green roofs, rain gardens, permeable pavers, shade trees, and more. These practices allow rainwater to stay on site and soak into the ground, where natural processes help remove pollutants.” It is part of the District of Columbia’s Department of Energy and Environment (DoEE).
It turns out that what I saw was part of one of these programs - a bioretention project, which is why I had that "attention - retention" play on words above.
What’s bioretention? Turns out it’s relatively new and quite interesting. The following description comes from a Massachusetts DEP (Depertment of Environmental Protection) Clean Water Toolkit site.
Bioretention areas (also referred to as bioretention cells or rain gardens) use soil, plants and microbes to treat stormwater before it is infiltrated or discharged. Bioretention areas are shallow depressions filled with sandy soil, topped with a thick layer of mulch, and planted with dense vegetation.
Stormwater runoff flows into the bioretention area, percolates through the soil (which acts as a filter) and eventually drains into the groundwater; some of the water is also absorbed by the plants. Bioretention areas are usually designed to allow ponded water and with an overflow outlet to prevent flooding during larger storm events. Where soils have low permeability or where faster drainage is desired, designers may incorporate a perforated underdrain that routes to a storm drain system.
Bioretention areas can provide excellent pollutant removal and recharge for the “first flush” of stormwater runoff. Properly designed bioretention areas will remove suspended solids, metals, and nutrients. Distributed around a property, bioretention areas can enhance site aesthetics. In residential developments they are often marketed as property amenities. Routine maintenance is simple and can be handled by homeowners or conventional landscaping companies, with proper direction.
To learn more about this, I started doing some research and found these great summary videos, the first from Alberta, Canada, and the second from Clemson University:
In Part 2, I’ll provide you with a more in-depth view of the RiverSmart project and the companies, products, and project stakeholders behind this particular bioretention cell. I actually had a chance to talk to the company partnering with DoEE to execute this project. I’m looking forward to finishing that piece in the next few days.