news from the waterfront by Tim Matson
Not long ago a brook running through your land might inspire plans for a pond. On flat terrain the pond would be excavated directly in the path of the stream. Along a sloping valley brook you might do less pool digging and more dam building to capture the water. Either way, stream ponds were a popular building style. No more.
Recent wetland laws have nixed stream alterations, and pond builders have to get more creative about finding pond sites with adequate water supplies.
However, streams still tempt property owners with pond dreams. Recently I visited a rural home with
a terrific southern view over a valley brook. The owner had purchased the acreage with some hope he might be able to site a pond in the stream. I explained that wetland laws would likely halt his dream stream pond. If he doubted my skepticism, a few calls to state and federal natural resource agencies confirmed the stream pond prohibition.
Nevertheless, I wanted to point out that he had a beautiful stream running through his woods and fields, with its own kind of pond potential. I suggested we take an exploratory walk along the stream. Uphill from the field, the stream
ran through the woods and included rocky twists and turns, scenic waterfalls, and pools. I pointed out where one waterfall dropped into a wide pool, and the stream had created a pond of its own, naturally.
We discussed some of the ways stream owners
create wading and swim pools without significantly altering the stream. I suggested looking for natural pools that form below a waterfall. Where waterfalls drop into a flat area you often find that the water creates an excavating action that not only carves out a pool, but keeps it cleaned out. Sediment eroding downstream doesn't get a chance to accumulate in the pool because the waterfall keeps flushing it further downstream. Sometimes it's possible to mimic this effect by simply moving a few stones to create a waterfall. Natural pools are often traps for fallen logs, branches, or leaves that can be cleaned out to deepen the pool. Sometimes a loose dam of stones is laid at the low end of the pool to help hold water. In addition to acting as a swimming or wading pool, these stream ponds can become sauna pools. In winter the waterfall keeps ice from forming on the surface. (It helps to be steaming hot when you hit the water.) Build a sauna bath near your stream pool, and you'll have a spa.
Years ago, before I got involved in pond building,
Vermont stream pools were the go-to places for cooling off. One nearby river had a run of ledge down the middle that created a series of "pot holes," swimming pools that had been popular for generations. Not far off in the same river a 50 ft waterfall had carved out a swim pool that attracted swimmers, if they had the nerve to make the climb down.
Because of seasonal fluctuations in water flow, stream pool depths can vary dramatically. A pool
Using streams to feed constructed ponds is a tradition fading away in the face of wetland protection laws. But if you have a stream, why not let nature give you a naturally made pond.
that might be fine for diving during a high flow period might be dangerously shallow in dry weather.
Be sure to check pool depths before jumping in or diving. The same goes for rivers with hydro dams that drop water levels to generate electricity.
February 1, 2015