Holleman: How we can turn SC dam failures into a win-win for lake residents, community

The failure of dams in the Midlands and elsewhere in South Carolina has been a tragedy, but it also offers the state an opportunity to take a step forward for public safety, neighborhoods, rivers and streams. Rather than rebuilding them, why not consider eliminating many of these dams and converting the former lake beds into neighborhood parks with free-flowing streams?

Dams and small lakes are sometimes viewed as neighborhood amenities that provide for recreation and increase property values. But open green spaces and walking trails continue to grow in popularity, can be used by more people and increase property values too. And they do not have the downsides that come with dams and small lakes.

Tommy Wyche, the Greenville conservationist who founded one of the state’s first land trusts, had one land acquisition rule: Never buy a dam. He learned the hard way that owning an earthen dam is expensive and dangerous. As the dams age, it is difficult and costly to safely maintain them. For many dams, particularly those in urban settings, failure threatens not only downstream property but people’s lives. In short, if you own a dam, you are taking on a big expense and risking significant legal liability.

Dams can make bad weather events more dangerous. Heavy rains, tropical storms and hurricanes cause flooding in any event. But a reservoir behind a stressed earthen dam raises the stakes. Even when dams hold, they increase upstream flooding during periods of high water, as water backs up behind the lake. The existing lake occupies a flood plain that otherwise would absorb the stream overflow caused by a storm. And if a dam breaks, the consequences are much more severe than those from a rain-swollen stream.

Dams are also bad for rivers and streams. Contrary to what many people think, dams and small lakes waste water. A great deal of water evaporates from the lake because the flat, large surface area is exposed to the sun. More water is lost through seepage into the ground, when it otherwise would flow downstream. Both evaporation and seepage rob streams and rivers of large amounts of water that would support healthy natural river systems and the animals and fish that depend upon them.

Small lakes can also contaminate clean water. They receive and collect polluted stormwater runoff and fill up with dirty sediment. The water behind dams is heated because the large, open surface is exposed to the sun. Dams result in shallow reservoirs of unnaturally hot and polluted water that harms native fish and wildlife.

Imagine this alternative for a neighborhood: If the dam is gone, the former stream can re-establish itself. The stream and connected river system will have more water flowing through them day in and day out, and a more natural flow. Instead of an expensive, problematic dam and a lake, a neighborhood or subdivision can have an area of green space and trails with a stream flowing through it. And restoring the green space and the free-flowing stream can be much cheaper in the short and long run than reconstructing a failed dam or repairing, maintaining and insuring a defective one.

If the dams that failed are not rebuilt, communities can still have recreational space while also enjoying free-flowing streams, more water in the streams during normal and dry periods, cleaner streams and rivers, fewer worries, much less expense and a reduced risk of major catastrophes.

It was a tragedy when these dams broke. Now, there is a chance to choose a different path forward.

This story was originally published November 7, 2015 at 6:22 AM with the headline "Holleman: How we can turn SC dam failures into a win-win for lake residents, community."