Wednesday, January 5, 2011
Water and Wetland Recharge in the Winter
Most rural landowners and all farmers have a good idea of how important groundwater recharge is to replenish the water table every year. When you're dependent on a well for drinking water, this is pretty important. We likely associate the water recharge with the spring melt in April, when all the streams flow high, the ground is often soggy, and water is percolating into the ground.What we may not realize is that this also happens during a winter thaw. The streams run high then too, if only briefly, and water is sinking into the ground, recharging the water table and any nearby wetlands.Rural ponds show the same pattern, the water level often dropping over the summer, but rising again in the winter. Through my own observation I've learned that rural ponds often regain their high water level during winter thaws rather than in the spring melt - indeed, by the time the spring melt happens, the pond has already risen to the high water level of last year.After last week's two-day thaw, water recharge around the valley was obvious, especially in the wetlands, a clear illustration on the surface of unseen groundwater recharge going on beneath the surface too.