Editor’s Note: This is a column on area watersheds by Blyden Potts and guest columnists to spread awareness of the area’s tributaries and the efforts of area volunteers to keep them clean.
Construction began Monday on the installation of mudsills and log vanes in the streambank at Shippensburg Little League’s Doc Norcross Stadium, on South Fayette Street. This MSWA project, in conjunction with Shippensburg Little League, has been long in planning and has finally come to fruition.
The Middle Spring Watershed Association is always looking for projects to improve our local streams. In past years, MSWA prioritized projects to work on using the Middle Spring Creek Watershed Implementation Plan (WIP) produced by Cumberland County Conservation District and RETTEW Associates (December of 2009). That WIP identified 40 key areas along Middle Spring Creek and its tributaries where projects could have substantial impact on stream health. Several of those sites have been addressed in the past decade.
The ballfield is WIP Site 18. There has been substantial streambank erosion for over a decade. The stream has been moving west, a couple inches each year, eating into the ballfield property and adding additional sediment to the stream.
The funding, design and permitting process that led to this construction began more than three years ago.
Shippensburg Little League and Franklin County Conservation District were interested. The PA Fish and Boat Commission (PFBC) was interested in also improving fish habitat in this portion of the stream, and provided the design for mudsills and log vanes, two best management practice (BMP) improvements that both improve fish habitat and stabilize the bank against erosion.
Mudsills are logs near the waterline parallel to the streambank, anchored every 20 feet or so with a sill log trenched into the bank perpendicular to the stream, and backfilled with crushed stone. They armor the bank against further erosion. Log vanes are logs angled into the stream from the streambank. They slow current and deflect it away from the bank, while providing fish structure and small pools. Each of the structures improves the spaces in the stream for brook trout and other aquatic species. They should solve the erosion issue almost immediately, and have a positive impact on trout populations, over the next year or two.
The mudsills and log vanes installed this week are not the end of the project. Later this fall, we will plant a riparian buffer along the stream on the part of the ballfield property not immediately adjoining the ballfield.
That will further improve stream habitat in coming years, by providing shade, which will keep the stream cooler, and woody detritus, which provides habitat and food for that macroinvertebrates that trout feed on. It will also improve streambank stabilization in those sections where mudsills are not being installed and reduce runoff, though this section is not noted for runoff issues. This week’s installation is a big step forward in MSWA’s ongoing efforts to improve our local streams.
In other news, the Conodoguinet Creek cleanup planned for this past Saturday never happened. It was canceled as a result of the heavy rain last Wednesday. Water levels, as measured at the USGS gauge at Hogestown, shot up in just 24 hours from 1.2 feet to over 4 feet, with corresponding water flows increasing from about 150 cubic feet per second to over 1,800 cubic feet per second. That was the highest water the gauge has seen since early April, and the fourth highest spike event of the year.