Calhoun County floods. We all know this. Worse, we have accepted this.
Every time we have heavy rains, the waterways swell, roads are closed, homes and businesses are damaged, God-knows-what gets washed downstream, school is closed, and countless other injuries and inconveniences are suffered by our community. After each flood the injured look to the Commission, the State, the Feds, NGOs, and charities to be made whole.
This reactive mindset has become entrenched and accepted. A proactive Commission would be preventing a future flood even as they make citizens whole from the last flood.
While there’s little to be done directly on the Little Kanawha, with its flow and level controlled by the dam in Burnsville, there is much that can be done on its tributaries. The the West Fork at the Arnoldsburg Y, for example, is a full 50’ higher than the Little Kanawha in Grantsville and over 100’ higher than its confluence with the Little Kanawha at Creston. No, the Little Kanawha would be lapping at the parking lot behind the Dollar General in Grantsville before it reached the same elevation as the banks of the West Fork in Arnoldsburg.
Passive flood control structures such as weirs are proven, long-lasting, effective, safe, and inexpensive methods to control riverine flooding. A weir, like a dam, is a structure that holds back some water in a stream, but it differs in two critical ways.
First, a weir is designed to have water flow across its entire top, not just a small spillway. Second, a weir is totally passive, requiring no operator to manage water release for its safe operation. These two differences make weirs far safer than dams.
In the oldest settled areas of the Eastern Seaboard stone weirs dating from the 18th and 19thcenturies are a key part of the current flood control systems. Originally constructed to raise water levels to provide power for mills, these structures have been modified for flood control and remain sound and operational centuries later. In the UK, there are truly ancient weirs still in use that were present prior to the Domesday Book of 1086. With maintenance a few times a century, these structures can function indefinitely.
A weir can be used a few ways to manage flooding. One arrangement, the top-flood pond, has a pond held back by a crenelated weir. In normal conditions, the water flows over the weir in the low places between the crenelations. When flow increases, water builds up behind the crenelations, increasing the height of the pond by up to several feet. If the water exceeds the capacity of the weir, it simply flows over the top, and the flow rate returns to the level it would have been if the weir weren’t present.
Another arrangement is a dry weir, in which a drainage culvert flows under the weir. In normal conditions, the culvert allows the stream to pass unimpeded. When flow increases to, say, twice normal flow, the water begins to build up behind the weir, limiting flow to twice the normal rate until the weir reaches capacity, after which the flow over the top of the weir is about what it would have been if the weir weren’t there.
In either arrangement, the idea is to build a temporary storage capacity into the waterway. This way, an hour of extreme downpour might be drained downstream over several hours, limiting the flooding. By working upstream and building a series of small weirs across the tiny creeks, runs, and other tributaries, we can reduce the frequency and severity of the flooding downstream.
The exact form any flood control system Calhoun County might develop will require much research and discussion. As candidate for Commissioner, I have already begun very informal initial talks with state and federal agencies regarding the possibility of such projects and been met with a lot of enthusiasm. In a relative sense, top flood ponds and dry weirs offer a very inexpensive solution to an expensive problem. Controlling flooding is of interest locally; controlling the pollution that results from flooding is of interest nationally. Everything that goes into our water here is felt all the way to the end of the Little Kanawha, Ohio, and Mississippi rivers.
Houners shouldn’t accept the status quo of flooding. Together we can address this issue, improving our quality of life and making this county more attractive for opportunity.
