news from the waterfront by Tim Matson
On a drive last summer along a road I hadn't
traveled in a while I was surprised to come around a corner expecting a familar sight, but it was gone.
I'd been expecting to see a hilltop pond that once caught my eye because of its high elevation and the scenic mountain view it reflected in the distance. I pulled over and stood by the roadside looking at what was left: A dry depression filled with grasses and brush. I wasn't sure who owned the gone pond, and because I had an appointment to keep I didn't have time to find out or ask what happened. But it was easy to tick off a few common explanations for a pond disappearence, especially since I'd recently worked on a pond that was scheduled to be erased.
When you build a pond and come to love it as a living part of your property, the last thing you imagine is losing it. But it can happen. There are several reasons for ponds going missing.
This constructed pond once offered a spectacular waterscape
at the top of a Vermont mountain.
The first and perhaps most common is neglect. Ponds need maintenance, especially as they age. Inflows and spillways have to be maintained, invasive plants and algae controlled, water supply made reliable, and dams not allowed to deteriorate. When one or more of these elements is allowed to slide, the pond will start to fade away. Most commonly, if the water supply is not maintained or leaks are not fixed, the pond water level will drop, and the greater the drop, the more ground emerges for plants and grasses to grow and replace the pond.
A loss of water volume can also occur if sediment is allowed to fill the pond, and the pond then loses depth and surface size, and the incoming fill creates a medium for plant growth.
Although many of the above effects are often due to
gradual neglect, one big storm can erase a pond with a single punch. Most commonly, a flood will fill the pond with sediment and/or destroy the dam.
Sometimes animals are to blame. Beavers can plug a spillway, with the consequent flooding taking out the dam; or they can build ponds in the supply streams that cut off water supply, or cause erosion that damages the pond with flooding and sediment loading. Muskrats can also dig holes in a pond and trigger leakage and pond failure.
Sometimes ponds are intentionally removed by their owners. Often this occurs when a pond was improperly constructed and fails to hold sufficient water. Attempts are usually made to fix the leaks and/or add supplementary water, but when these rescues fail, or the price tag for remedies exceeds the budget, the pond may be refilled. I once saw a large embankment pond so resistant to repairs that the owner refilled it and planted an apple orchard.
Ponds may also be removed if they were built illegally. Every year or two I hear about a pond that was built without permitting in a protected wetland. When the owners get caught there is a fine and the wetland has to be restored, often at considerable cost.
This is what happened after the pond drained
and the weeds took over.
Looking over the gone pond that day, I missed the sparkling water, but reminded myself that nature's model for constructed ponds is the beaver pond, and their fate is also to eventually disappear. As the animals use up the food supply around the pond, as sediment fills the basin, as the dam deteriorates, the beavers
move on. Often the pond they leave behind turns into a wetland or a field, which supports a population of wildlife and plants different from pond life, but just
as ecologically valuable.
January 1, 2015