cicada summer

Lemont, Illinois. It's hot and windy. The sound of cicadas is continuous, unbroken, the sounds of a few nearby individuals distinct above the more distant, all surrounding monotone. Cicadas sit clearly visible on nearby trees and shrubs, the nearest currently about three feet from me. More fly erratically past, their stubby bodies seemingly barely under control. Every now and then I need to lean a little to one side as a cicada mistakes me for a tree and tries to come in for a landing. It doesn't take much for them to miss, but when I'm distracted by a phone call two or three take up temporary residence on my cap or camera bag. Other species play among the cicadas, including a variety of early summer dragonflies; Libellula pulchella, L. lydia, L. luctuosa.

I'm standing about 300 feet from where I first entered this site 19 years ago, following Marcy DeMauro and Dave Mauger down a steep, 75-foot high bluff face. What we found at the bottom was a series of sedge meadow and marsh openings, a series of springs and seeps emanating from the bluff. These little gem-like natural communities, an endless variety of shades of green, are interspersed among the evidence of more than a century of human disturbance.

Thousands of years ago, the mile-and-a-half wide valley held a much larger river. The outlet of post-glacial Lake Chicago poured out through here, scouring down to the dolomite bedrock. Over time, seepage from the deep glacial till on either side of the valley found it's way to the bottom, trickled out over the bedrock, formed shallow wetlands. High spots supported a low-growing, xeric community only a few feet above standing water. In this new environment, plants capable of growing on thin soil and able to tolerate the calcareous conditions thrived, while more common species could not compete effectively. The result is an accumulation of rare communities and species.

Native Americans certainly burned the surrounding uplands, keeping them in a prairie and savanna condition. Later, humans with better tools came along and decided to connect the great waterways. The Illinois and Michigan Canal followed this low spot, parallel to the Des Plaines River which meanders through this much too large valley. Later came the Sanitary and Ship Canal, carrying Lake Michigan water (and Chicago's waste products) across a continental divide and toward the Mississippi River. With the larger canal came exotic fish, and commerce. Water access made quarrying economical, and soon barges carried flagstone and lime and later aggregate to the downtown Chicago market.

The site I stand on was quarried from about 1889 until 1918. The pits, mostly shallow, are closer to the river. Spoil piles follow the base of the bluff for at least half a mile, leaving only this thin ribbon of wetland intact. Except that the bluff seems too steep here, relative to nearby examples. Vertical bits of bedrock are exposed, head high. It seems that these pristine wetlands may not be so pristine; they may instead have regrown where soil was removed to get at rock in the base of the bluff, leaving behind a flat, bare dolomite pavement. As before, the water seeped out of the bluff and over the rock. As before, sedges and rushes and cattails lived and died on the gradually accumulating organic material. When I first visited in 1988, I saw the results of 70 years of recovery, maybe a little more.

In 1988 this place was very difficult to get to. Scaling the bluff was actually the easiest way in, if a bit risky. The spoil piles were and are to the south, 20 feet high and several hundred feet across and of very uneven footing. Then, they were covered in a nearly impenetrable thicket of honeysuckle with scattered cottonwoods poking out the top. To the east, the remnant wetlands had also become overgrown and a combination of deeper water and dense shrub cover made walking very difficult.

About three years ago, the Forest Preserve District of Will County cleared the honeysuckle south of the wetlands, cleared shrubs off the face of the bluff too, and also where they had begun to encroach into the remnant wetlands. They also constructed or upgraded a gravel road south of the spoil piles and separating them from the open water pits. It still isn't an easy place to get to, but at least it's now possible to hike here in 10 or 15 minutes instead of in several hours.

I'm here to use this place as a reference site. Similar spring-fed rivulets are going to be restored about half a mile east of here, at the base of the same bluff. We've already had the honeysuckle cleared there. assessed the existing condition, discovered that stormwater from a nearby culvert has dramatically altered the site hydrology and allowed the rivulets to headcut. They are deep, entrenched, cold, very unlike the ones to the west. We've decided how to divert the stormwater away, thus eliminating the biggest problem. Next, we need to better understand what we'd like to put back. One way to do this is to examine the best remaining nearby example of a similar community.

I've learned a few things today. One of them is that just putting back a rivulet isn't enough. It turns out that the main rivulet... there are dozens of them braided among the sedges in some places... remains too cold to provide the habitat we need. Today, in this 91 degree heat, it leaves the bluff at 56 degrees, and never climbs above 66 degrees. A few feet away, the secondary channels are 10 or 11 degrees warmer, while water in the crayfish burrows, thought to be a key habitat component, averages about 69. And there are no crayfish burrows in or immediately adjacent to the main rivulet.

So we need to think about the entire wetland complex, not just the rivulet. It's also clear that we can't over-engineer this; it would have been impossible to pre-visualize the complexity of what I see here around me. Rather, I'm thinking that we need to create the local landscape within certain broad constraints, and then let the water find it's own way, and allow for change over time, which will happen whether we plan for it or not.

I'll be back out here tomorrow to think about these things some more.

success of sorts

This evening, on the way into San Francisco, I took a short detour through San Rafael.

In 1993-94 I wrote a wetland mitigation and monitoring plan and helped obtain a 404 permit for a small two-lane bridge associated with a road extension, and including a couple of acres of salt marsh restoration. The project hadn't gone anywhere immediately because of funding gaps, and then I got busy with bigger projects in other parts of the country. So even as I regularly visited my other California restoration from the pepriod, in Solano county, I assumed the one in San Rafael had never been built. No road, no mitigation. The engineer who had been PM on that project had moved on, so for years I had nearly forgotten about it.

Just a few months ago someone told me that the road had eventually been built after all, I'm not sure exactly when. So today I went to look. And there it was; the bridge, exactly as in the drawings; the salt marsh bordering the tidal slough, exactly as I'd helped design it, with all the right species of plants. The bordering bike trail, exactly as planned. A vibrant mixed-use surrounding community, impossible to be sure of back then when a contaminated vacant lot had been one of the nearest neighbors.

I need to go back with a camera and take a really close look. But it feels good to see projects taken to completion, and looking a lot like they're supposed to.