Last week, West Virginia got a sad replay of earlier events in southern Germany when the governor declared a state of emergency in 44 counties. Floodwaters swept through the state, taking more than two dozen lives.
One particularly hard-hit area was the Elk River. It emerges from a system of caves in the northern part of the state after flowing underground for 5 miles. Limestone tends to form complicated cave systems and drains sporadically and quickly.
In the past, floods were common in the Elk’s lower sections. To counteract this, the Corps of Engineers built a dam that formed Sutton Lake, completed in 1961.
Below the dam, State Routes 4 and later Route 16 wind their way through beautiful valleys, with some of the most gorgeous views of the West Virginia landscape. Small towns like Ivydale and Clendenin hug the river banks.
This pristine rural setting, “almost heaven” in an old John Denver song, was shattered when the area received up to 10 inches of rain on June 23 and the following day. By the weekend, waters had risen to the point where Clendenin was only accessible by helicopter.
Sutton Dam doesn’t appear to have helped much in this case because tributaries below the dam were swelling the Elk River, and the valley slopes are steep. Just like a funnel, the valleys in mountainous West Virginia collect water quickly.
But floods aren’t caused solely by water arriving in the stream. Rain entering the mountain rock mass puts the groundwater under so-called hydrostatic pressure. Water is forced downward inside the bedrock, and the only place it can emerge is in the deep valleys. This is why a river can rise so quickly.
It brings drainage water directly, but it is also supplemented by water rising under pressure from below. People have often observed during flooding how water seemed to be coming straight out of the ground.
Apart from the steepness of the slopes, another fact compounded the problem. Many towns in West Virginia’s valleys are on floodplains. Those are the only places where level ground is available.
Clendenin had to pay a heavy price for its location, as did the town of Richwood, where the Cherry River reclaimed its entire floodplain with surging waters. It confirms the risks of living on flat ground near a river, but that knowledge won’t lessen the grief and pain of the victims.
Rudi Kiefer, Ph.D., is a professor of physical science and director of sustainability at Brenau University. His column appears Sundays and at gainesvilletimes.com.