March 2016 – View of the stormwater channels in the World Garden Commons – Photo by Justin Klabo, PE CFM
Earlier this month, Nick the surveyor walked the channel at World Garden Commons and identified really hard areas (clay sub soil) and very soft areas (remaining topsoil/silt) with Justin, a stormwater engineer at AE2S and Brian a landscape architect from Land Elements. They walked the centerline of the channel and found varying conditions along the entire length. The conditions varied from vary hard surface (clay areas) to very soft and mucky where there was still topsoil from the grading done last year after the concrete channel was removed.
Last fall, after the concrete channel was removed, we constructed what would be considered a “stable” channel section but we did it with topsoil which is highly erodible. The material has washed out, creating an “incised” channel. As the section experiences higher flows, it will start to widen by eating away at the banks, primarily the south side and depositing material in the channel or washing it downstream. Ultimately we would like to have a channel that has is stable with a low-flow channel but at the same time has a high flow area where the water is able to “spill” out of the banks and into the upland areas (floodplain).
March 2016 – Measuring the stormwater channels in the World Garden Commons – Photo by Justin Klabo, PE CFM
March 2016 – Measuring changes to the stormwater channels in the World Garden Commons – Photo by Justin Klabo, PE CFM