An acute water management problem? Updated 1/3/21

The photo shows a problem on the east side of the parking lot behind Sykes Student Union in West Goshen. A large paved surface is drained by several grills, but excessive water flow has caused subsidence behind this yellow barrier.

As you can see from the first photo, storm water now bypasses the grill and flows into the pit. If we look down there in good light, we find that the pavement has subsided into the bottom of the pit (which is about 3 feet deep) and that not only water coursing off the lot but also the contents coming in from a pipe to the left flow into a larger pipe under the grill (photo 2).

Where does the water go from there? The lot itself includes no retention basin, and on the south side of the lot–and presumably from the drains around the lot–water runs off into a wooded area.

Looking closely there, we see (photo 3) a substantial pond stretching along the whole south side of the parking lot. Is this WCU property? Is it a planned retention area? Does it filter out car and road salt contamination and allow water to soak into the water table? If so, good!

This isn’t just a drainage question, but a historical problem. The main WCU campus was built on the upper reaches of Plum Run, which was put undergrouind; its water now flows into the Brandywine River at route 52. WCU of course now knows the needed corrective measures and has done well to install retention basins on New St. south of the Recreation Center, on Sharpless St. outside the Business and Public Management Center, and south of the lot at Roslyn Ave. south of Rosedale Ave.

Is Sykes parking lot adequately served by the above-identified pond area? Is it a good location for future retention basins and at the same time, some trees and rain gardens to absorb water and improve the scenery?

At some point to the south, a stream (photo 4, seen from the bridge at Oak Lane, with the added attraction of a cold groundhog (possum?) hunkering down to the left of the water) emerges from among private properties that prevent public access for the desired observations.

At any rate, the storm water south of Rosedale drains down toward WCU’s much-appreciated 126-acre Gordon Natural Area, which shows signs of stream erosion on the far bank (just behind the unfortunate extraneous object in photo 5, taken 12/13/20):

That’s what water does, seeking the easiest path downward, and when more of it runs off than an existing natural watercourse can handle, it damages built infrastructure, erodes stream banks and potentially causes flooding.