GREEN BAY, (WFRV) – Every time it rains or snow melts, this dirty, untreated water ends up in our waterways. But after a recent construction project on Webster Ave. in 2019, measures to treat this water in a green way were implemented with a so-called gully.
“A swale is a vegetated ditch and the intent is to channel stormwater through this ditch allowing the vegetation in the ditch or swale to remove pollutants that would otherwise pass through our stormwater system” , explained the director of public works of Green Bay, Steve Grenier. .
The gullies help filter any dirt from the roads and can make the water dirty. The vegetation in the swale also filters out the phosphorus that plants need to grow. This phosphorus is what can lead to the algal blooms seen in the bay and Lake Michigan.
“Unlike grass which has shallow root systems, these plants have deeper root systems,” Grenier said. “They are able to handle wider ranges of precipitation conditions. They are drought tolerant and able to handle larger amounts of water as it comes.
And while the swale is a great option for capturing and filtering stormwater, the city is using other ways to use green infrastructure to help solve the stormwater problem.
“One of the most common types of gastrointestinal activity you’ll see is permeable pavement. And what it is is different from conventional pavement like you see here on Webster Avenue, this pavement also allows water to seep through,” Grenier added.
The director says the city received a grant to install the previous roadway during construction on Emily and Eliza streets this year.