Here's an unusual take on restoration. Although I had a lot of involvement in walking this one through the process, as the chair of a working group with something like 17 stakeholders... the concept, and much of the design, were done by Dan Soluk of the University of South Dakota.
The overall concept was to restore breeding habitat for the federally endangered Hine's emerald dragonfly. At a couple of other nearby locations, that was done in fairly conventional ways. We found places where a water source was available, where things had been somehow modified, and we put them back to a functional level. I'll talk about those another time.
But at the site in the photo above, at Waterfall Glen Forest Preserve in DuPage County, Illinois, Dan found a way to construct an experimental system, one where graduate students will be able to manipulate flow rates and temperatures, and monitor effects on larval survival. That information, in turn, can be used to guide future restoration efforts.
It started when we visited a former fish farm recently acquired by the Forest Preserve District of DuPage County. A series of artesian wells had been sunk, and the groundwater fed into several ponds used to raise trout. One of the wells, the highest one up the terrain gradient, was leaking severely. A few dragonflies had been seen hovering over the streamlet flowing down over what was essentially a mowed grass lawn.
Early discussions on creating a streamlet with native vegetation quickly determined that we'd need to pipe the water laterally first, because there was a house and a septic field in the way of a natural gravity flow. Early in the conversation, Dan offered the idea of putting flow valves on the outlets of that pipe, and developing a system for field experimentation. It's rare to have such an opportunity, we couldn't pass it up.
I completed my nearby projects by early 2008, and moved on to other things. The work at Waterfall Glen had barely started then, so it was just this past summer that I finally had an opportunity to see what had been constructed from Dan's concept.
The rock basin in the photo is one of several intended to catch the outfall and prevent erosion. From there, the water overflows on the downhill end, on the right of the photo, and a small streamlet, 6 to 12 inches wide, a few inches deep, flows through planted wet prairie and into an existing marsh.
In the background, what was once a dense thicket of buckthorn has been cleared. The remaining trees show the effect of that recent past; where they had been shaded out, bare trunks reach for the sky. Eventually, perhaps the open woodland structure will begin to look more natural. The herbaceous understory is new, planted from seed, barely established. The ground had been fully shaded and almost bare at the start of the project. In the far background, the steeper bluff slope has also been cleared.
Initially, dragonfly larvae will be released into the new streamlets, and their three to five year aquatic development monitored. Probably, adult dragonflies from nearby natural habitat will also deposit eggs into the streamlets, if they're not intentionally screened from doing so. Eventually, the Forest Preserve District will redo the site, using the new data in the design of a more natural graminoid fen complex.
