Asheville, North Carolina Field Trip – Student Notes and Observations

3 Jun

Site 

 The Evergreen Community Charter School’s LID landscape featuring various stormwater Best Management Practices.

Discussion

 The site of the Evergreen Charter School formerly housed a Christian academy, but when the school changed to a charter school, the decision was made to implement a LID landscape on the campus.  The school applied for funding from an environmental grant with the goal of reducing the amount of impervious surface and improving the quality of water on the site.  On the tour, we observed several large bioretention areas that captured water off of the main buildings of the school.  There was a large bioretention area below the parking lot that captured runoff from a roof as well as from the parking lot.  The site also featured a conveyance channel with a series of step-down weirs, a constructed wetland, removal of curb and gutter systems, a biodiesel fueling station, and a cob structure.  

 This site is an excellent example of a holistic approach to treating water on a site due to the various BMPs found throughout the site. While some were more successful than others, it was really inspiring to see the BMPs implemented on such a large scale, especially at a relatively small school.  The bioretention areas adjacent to the school building looked like they were performing very well, with thriving plants as well as nice educational signs.  The bioretention area below the parking lot looked as though it was capturing a lot of water, but there were some structural issues where erosion had undercut the pavement where water entered the depression.  This could be remedied by the inclusion of rip-rap where the water entered to help dissipate the energy and prevent erosion.  There were a couple of missed opportunities in the parking lot, where more bioretention areas could have been included.  There was a narrow planted strip running down the center of the parking lot, perpendicular to the grade, and the class discussed how this could have been more successful if it was slightly depressed to allow for infiltration and pretreatment of the water upstream.  The class found a couple of areas where maintenance was needed including the buildup of silt and debris at bioretention entrances, and erosion on weirs, showing the importance of diligent maintenance on these types of systems.  I was very interested in looking at the planting palette in the BMPs and discovered that most of the plantings were native.  Plants included Itea, Clethra, Hamamelis, Amelanchier, Aescules, and Callicarpa, although the Callicarpa was the non-native species, so I feel like this might have been a mistake since everything else was native.  Overall, I was impressed with what I saw and thought this site could act as a good precedent for other schools, inspiring them to implement similar systems.  

– Written by Mary Archer

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: