Published 6:13 pm Tuesday, April 12, 2016
Isle of Wight County could have the raw material for creating a significant stormwater management tool tucked away in the county’s rural areas and not even realize it.
Let’s call it “plug a millpond dam.”
But first, to back up a bit, there has has understandably been a lot of public interest in stormwater management ever since the county enacted a new tax on county properties to create a fund to improve water quality.
Naturally, no one is happy with the tax, but more than anything else, county residents have wanted to know how, specifically, the new-found tax dollars are being spent to actually make Chesapeake Bay water quality better. It’s a reasonable question, but not one for which we have found answers that are fully satisfactory. That’s because a lot of the new tax dollars seem to be going into administration of stormwater policies rather than actual construction. That may be necessary, but is always smells a bit like just more government folks to people who are paying the taxes.
Still, the county is building some stormwater management facilities — mainly stormwater retention ponds — that are a primary means of preventing unwanted silt and high nutrient loads from entering tidal tributaries of the Bay.
All of which led to an interesting discussion recently. Smithfield businessman Fred Walls, who grew up in Boykin’s Tavern, wondered why the county didn’t repair the old Isle of Wight millpond dam that sits next to Courthouse Highway, at the edge of the county’s property.
At first, I thought, why spend the money to do that and thus create a pond that would no seemingly useful purpose other than to look pretty and maybe hold some fish.
But was that true? What if the pond were used for the simple, but important, purpose of filtering water flowing downstream into the Chesapeake watershed?
Then I thought about another breached dam, the one that until a few years ago formed the Wrenn’s Millpond. Every time there is a heavy rain, water flowing through that broken dam takes a huge amount of silt across Wrenn’s Mill Road and downstream from there into the headwaters of the Pagan River. The water flowing across the road following heavy rains is sand-yellow, a telltale sign that it is absolutely loaded with silt that most likely has been in the bottom of Wrenn’s Millpond for several hundred years. That silt is now flowing freely into the Pagan.
I talked with Chris Moore, the senior Virginia scientist for the Chesapeake Bay Foundation about the idea of plugging old millpond dams to reduce siltation, and asked, is it a stupid idea?
No, Moore said. It’s just one that has to be studied on a case-by-case basis. The CBF’s concerns are multiple. While stopping silt and nutrients is crucial, it is also important not to block streams that saltwater fish use as spawning grounds.
Thus, he said, the idea of blocking former millponds may, in some instances actually be an inexpensive way of creating major stormwater retention ponds. But that has to be evaluated in light of the dam’s geographical location and whether the stream it once blocked is used by spawning fish.
Worth looking at? Who knows. But if re-establishing a couple of the county’s old millponds served as an inexpensive way of improving water quality in local tributaries of the Chesapeake, then studying it might be worth some of the time of those folks hired by Isle of Wight to do just that.