trunk line under the street . Roadway drainage flowed directly into the storm sewer without total suspended solids ( TSS ) removal or total phosphorus ( TP ) control . The untreated flow then drained into adjacent waterways .
“ Stormwater management was a concern along this route ,” said Troy Robillard , manager of transportation services at Ayres ’ Green Bay office . “ The roadway was within a floodplain , and the storm sewer was undersized . That was one of the more challenging parts of this project . There was simply no room to install stormwater management features .”
After examining several alternatives developed by Ayres , the City decided to widen the corridor to accommodate a biofilter system that would manage runoff while making the area more visually attractive . That meant acquiring a significant number of pieces of privately held real estate , including 24 houses .
“ We had to remove that many houses because there was no room , no other way to detain the stormwater , to keep it from discharging directly into a waterway ,” Robillard said . “ Once we had that space , we were able to consider the needs of the City and suggest measures that would manage stormwater while adding value to the neighborhood .”
North Webster Avenue is still four lanes wide , but between the opposing traffic lanes there is now an attractive , landscaped median . “ The median is inverted – ‘ V ’ shaped – planted with grasses that do not require mowing . We ’ re using it for biofiltration ,” Grenier said . “ We worked with landscape architects on the City staff to select plants that work well to slow the flow of runoff and encourage infiltration to the soil .” www . AyresAssociates . com 33