Last week was NOFA Organic Land Care's Advanced Workshop It's All About the Water: Managing Stormwater with Rain Gardens, Permeable Surfaces and Tree Boxes at the Beardsley Zoo in Bridgeport, CT.
The first presenter was Donald Watson, an Architect with Earthrise LLC and presented about a streamside buffer demonstration project he designed in Trumbull and about his work on the Beardsley Zoo's 319 Grant to put in biofiltration features in the parking lot.
Michael Dietz, the Program Director of CT NEMO taught the class about how to calculate runoff volume and amounts of pollution coming from an area. Then Michael and Jeanne Yuckienuz, a Senior Keeper at the Zoo and Accredited Professional, brought the group outside to see the site of the proposed project. The area around the flagpole will be excavated and a rain garden will be established that absorbs water as it flows from the parking lot.
After lunch Lisa and Kyle Turoczi from Earth Tones taught about choosing trees, shrubs, ground cover and flowers for rain gardens of all sizes and locations. Afte rtheir presentation the group went outside and identified the plants grown in the Beardsley Zoo's existing three rain gardens surrounding the Hansen Education Center.
This third raingarden was planted with inkberry, cinammon fern, royal fern, low bush blueberry, and azalea.
Tom Barry, from Read Custom Soils presented on Engineered Soils for Low Impact Development. Tom discussed the mixtures of soils required for rain gardens that will allow for water infiltration and percolation, sequester pollutants and support plant growth. Soil underneath permeable pavement should be structural planting soil that can support a greater weight without compacting (which would reduce the amount of water that could infiltrate and the rate). Tom also discussed the soils used on green roofs, which have to be very light while still allowing water to percolate and supporting plant life.
The next presentation was from Brendan Tyson from unilock who presented on all the different kinds of pavements that can be used to provide a hard surface that still allows nearly natural rates of infiltration.
The final presentation from Paul Iorio of Storm Tree and Stormwaterworks.com was about tree filters which are generally used in small parking lots in much the same way a storm drain is. Except many tree boxes (except those receiving large volumes of run off) do not connect to an underground pipe, but filter through soil and the tree's roots.