#58 Rebuilding the Rivanna at Bentivar

Originally Aired on April 19, 2007 (the week of the VT tragedy)

It’s another cool spring day, faint sun intermittently lighting up the pale greens and golds of emerging leaves. I am walking down a rough road from Bentivar Farm onto a vast floodplain. Sretched out before me are acres of lowland and wetlands that reach toward the point where the North and South Forks of the Rivanna meet. I know the banks from the river, having paddled both forks many a time, but today I’ve come to see restoration taking place in the flesh of the land itself.

My guide is Carolyn Browder, a restoration specialist for The Nature Conservancy, under whose care this bottomland has been for the last couple of years. She meets me by a small, unassuming stream at the bottom of the hill. It is here that, over a year and a half ago, the work commenced. The work of redefining the course of water flowing down from the surrounding hills so that it can do so without hauling loads of sediment and stormwater runoff with it.

Carolyn tells me parts of the story as we walk along stream, barely six feet across, and still running full from the rain of the last couple of days. Bubbling across a stretch of cobble, the water drops a foot over a large piece of cut rock, which has been placed strategically where an elevation decrease must be achieved without sacrificing the integrity of the channel. This channel has been purposefully rerouted to follow its historical course. Walking the moist ground, we can see where the rains had forced the water over the banks, the ryegrass bent like a comb-over and still mashed flat in downhill direction.

For decades, this rich bottomland was farmed, but it required work to drain the water from the floodplain enough to make planting corn even possible. This was accomplished by digging ditches to drain the water, and by using tile drains, terra cotta pipe sliced lengthwise and planted open side down, cupping the earth, while capillary action pulled the water along its course and towards the river. Meanwhile, the original stream coming down a crease in the hills above was routed so that it no longer bisected the fields and instead was tucked up against the hills lest it impede the work of farming this swatch of floodplain.

Land alternation had been heavy and significant long before this ditch and drain method was ever used. We know that earliest settlers set to work to clear the land, transforming forest into field, changing the relationship between the river and its floodplain forever. On the North Fork and the South Fork, indeed all along the Rivanna, you can see today the steep banks caused by the incessant erosional forces of mud-laden water washing off cleared land. In fact, the floodplain here sits some twenty feet higher than the river. This meant that the engineers designing a more natural stream channel had to build in a series of drops and slopes that would bring the watercourse into the river at a shallow and benign angle.

Carolyn’s job has been to oversee the work and continue to monitor its success as a restoration – making sure that the new stream reaches an equilibrium with its newly created banks and plateaus. That the disturbed land is kept clear of invasives such as Johnson grass. That high energy storms, such as those resulting from Katrina and Rita in the fall of 2005, don’t wash out the new stream as it’s settling in. That the right time to plant trees to form a protective buffer on either side is chosen wisely.

As we cross the stream, at another ledge of rock placed to create a drop and small pool that is now home to diversity of life, I start to gain an appreciation for the scale of the project. Looking back, I can see the sinuous curves, etched by clumps of grass and sedge that paint the landscape in subtle hues of green. A plover twitters across thirty feet in front of us towards the stream, disappearing into a camouflage of sandy soil and clumping grass. Every pool and every curve that is reinforced with boulders was conceived, then built, to give water a chance to be a stream in a channel that’s been designed s close as one can get to “natural.”

My boots are covered in muddy soil and there is a wide and open sky above. In a week that has been draped in horror and sadness so close to home, it feels particularly to good be walking a landscape that is surely in the process of change and healing.