Storm Water is Treated at Willow and Sauerkraut Lanes

Ever wonder what's going on with the stormwater area at Willow and Saurkraut lanes where the trees were planted and ponds created? Most recently some final touches have been added with the installation of mulch paths.

This project represents a complete conversion of previous 'dry' detention basin into a 'wet' treatment basin. Wet basins are artificial ponds with vegetation around the perimeter. 

Dry basins do not do a very good job of treating stormwater. They only  temporarily store the water after it rains and eventually discharge the bulk of the flow into the Little Lehigh.  

'Wet ponds' have two main benefits.

They are much more effective at slowing flow (decreasing flooding) and filtering pollutants. In addition, there are also long term savings in maintenance. The basin is only mowed once a year to prevent trees and shrubs from establishing in the areas intended to be meadows. The upper portion of the project has been planted with 150 native trees to create two woodland areas.

The whole project has a path system where students from Willow Lane Elementary School can learn about ecology in a living classroom. The retrofitted basin becomes a park-like setting and woodland for habitat and passive recreation whereas dry basins are large sterile areas often fenced off needing mowing throughout the summer and often treated with herbicides.

Here is a brief description of the system that was installed at Penns Meadow: (see picture)

There are three points where stormwater from Penns Meadow flows into the basin. Through various systems this water is filtered and the flow rate slowed.

For example, from the second input water flows into a forebay and then through a constructed wetland area and finally to the wet pond. The entire basin is fitted with an impermeable liner so unless there is a major storm event, all water that enters the basin is either is used by vegetation or evaporates. Only in extreme rain events does water flow to the Little Lehigh and even in these cases it is better filtered and slowed then in dry basins. 

This is a fantastic and much needed project in our township. The Environmental Action Council would like to see more retrofits of sterile dry basins. In the upcoming review of our comprehensive plan the BOC and planning commission need to incorporate more best management practices for future developments instead of large sterile basins that require mowing and herbicides.