Hinesburg
Hydrology
Water is the foundation of life. It is also a powerful and defining force in shaping the physical landscape. Though supple and yielding, given enough time water can carve through mountains of rock and redistribute once-solid sediments along the mutable banks of a meandering river.
For the past 10,000 years or so since the great glaciers retreated, Hinesburg’s landscape has been the palette upon which a host of surface waters have been busy carving new pathways into the soft sands and muds left by glacial Lake Vermont and the Champlain Sea (See Surficial section).
At present, the LaPlatte River to the north and Lewis Creek to the south are the dominant hydrologic features in the valley, both winding their way in sinuous patterns across the relatively level terrain toward Lake Champlain a dozen or so miles to the west. For the most part these waterways lack significant hydrologic head, and have rarely been harnessed for any significant industrial endeavors. However, since they course directly through the town’s prime agricultural lands, the LaPlatte River and Lewis Creek have historically been of great importance to farmers in providing irrigation for croplands and pasture for cattle. In fact, not long ago, farming practices in Hinesburg had resulted in the deforestation of the majority of the valley’s streamside woodlands, leading to severe bank erosion and a loss of valuable wildlife habitat.
Several recent restoration projects—many initiated by local farmers and in concert with volunteer support from citizens and students at UVM—have helped reinvigorate the streamside ecology by planting vegetation buffers. These forested riparian zones have in turn become essential habitat and corridor pathways for dozens of mammals, birds, reptiles, and amphibians.
Due to the steep grades and glacial till sediments that characterize the eastern side of town, the waterways that flow through Hinesburg’s hillsides are quite distinct from the snaking rivers in the valley. Most of the upland streams are smaller channels tucked in the rocky ravines between higher points of land. A good many of these are only ephemeral waters that drain the torrents of spring meltwater. Where the overlying surficial materials are thin or non-existent, the streams flow directly over bedrock, in some places etching marvelous cascades through the resistant rock layers. One of the most prominent locations in town where this occurs is along Pond Brook in Mechanicsville, where the water flows directly over the Hinesburg Thrust Fault. It is precisely because of the natural break in the bedrock that the water drops several feet. This waterfall, and many others like it in the area, was for decades at the heart of industry and development in Hinesburg, providing the power source necessary to run a variety of mills. Indeed, Lower Pond situated just to the north and east of the waterfall, was dammed in order to provide a steady flow over the falls. Though there are no longer any active mills along Pond Brook these days, the remaining dam structures throughout Mechanicsville are prominent reminders of how not so long ago the lives of Hinesburg’s citizens were intimately entwined with the local bedrock and the flow of water.
As already mentioned, one of the primary functions of wetland areas in Hinesburg today is to provide key habitat for a diversity of wildlife. In addition, the waterways are also of great recreation and aesthetic value to the town’s human inhabitants. The largest body of water on the landscape is Lake Iroquois, which Hinesburg shares with its neighbor to the north, Williston. Formed in the low-lying basin left after the glaciers retreated, Lake Iroquois is a favorite spot for boating, fishing, swimming, and hiking in the surrounding park lands.
Finally, it is worth mentioning that though we can readily observe water on the surface of the earth in ponds and streams, there is a fraction of rain water that is not taken up by plants, nor discharged downstream, but rather that infiltrates into the sediments and rocks below and becomes groundwater. Water moves differently through sand, clay, and rock fractures, yet regardless, where water collects underground is called an aquifer. Aquifers are of great benefit to humanity. Many of these formations are capable of storing and yielding great quantities of water – which in turn serve as the sources for the wells from which the citizens of Hinesburg draw on for their daily needs.