Heavy rains over the last year caused water to pour down the open meadow at Pleasant Hills arboretum. Often, it jumped the curb into the parking lot causing flooding.
Coming from the other side, water flowed out of the wooded area, filling the pavilion and leaving behind a mess of mud and rocks.
Board members for the nonprofit arboretum sought to fix the problem, while creating an educational tool for others surrounding stormwater management.
Their plan: Build two stormwater retention ponds/rain gardens with correlating swales to catch the water and slow it down. A trench alongside the parking lot with rocks then would further slow down the water before it heads into the pipes that lead to Lick Run, a tributary of Peter’s Creek Watershed. The hope is to stop it from going into the storm system altogether.
“We thought this could serve as an educational tool, as well as a functional tool for the arboretum,” board President Greg Smith said.
The Pleasant Hills arboretum received a $10,000 grant from the Allegheny County Conservation District for the project. An anonymous donor funded the remainder of the project, Smith said.
The A.W. Robertson Arboretum was founded in 1950 with the goal of preserving 16 acres of land for educational and horticultural purposes. Of the 16 acres, six are made up of a large meadow. The remainder is wooded land.
Crews started working on the stormwater management project on Sept. 3. The hope is for the project to be completed by the third week of September.
The swale will be filled with native plants, Smith said.
The rain garden will include natives seeds, grasses and water plants.
Two swales, or low tracks of land used to manage water runoff, will guide water to the smaller retention pond/rain garden next to the pavilion.
A wall constructed of Pennsylvania field stone also is being constructed around the pavilion, which was added nearly two years ago when Pleasant Hills resident Deborah Heylman bequeathed funds in her will to the nonprofit organization. The funds she left to the arboretum also were used to install a split rail fence.
The pavilion provides a place for people to sit and enjoy nature. It’s used nearly every day, said board Vice President Drew Ratti. Groups even come to use it in the summer to play their string instruments, Smith added.
For years, students from Jefferson Elementary visited the arboretum each fall and spring to walk the open meadow and wooded area and learn about the trees and land. The area is open for students and adults to learn, Smith said.
There now are more than 75 species of trees at the arboretum, Smith said. The oldest tree is 235 years old.
“Where else can you find a tree that old?” Ratti asked.
The hope is that when people see the stormwater management project the arboretum has undertaken, that they too, will do something to stop water from flowing into the storm system.
“If people see this retention pond, hopefully they’ll think, what can they do in their own yard?” Smith said.
People can use rain barrels or put in a pond of their own, Smith said.
Ratti noted that with this project, the arboretum really is looking at preserving the “past and future.”
Stephanie Hacke is a Tribune-Review contributing writer.