Since 2000, dozens of sinkholes have opened up in a 28.5-square-mile area stretching from Leesburg to Point of Rocks near the Maryland border. Although many of the sinkholes were less than a foot wide, at least two that formed in an area slated for a housing development were 30 feet wide and 30 feet deep, a county official said. Another in 2005 created a chasm in the middle of Route 15.A lot of land slated for development is on top of limestone karst. That's bad. When the water in the limestone drains out because we're using more of our available water than we used to, the ground becomes less stable, and the pores in limestone collapse, causing sinkholes.
The problem, county officials said, is rapid development of land that rests on soft, porous limestone, often referred to as karst. Another danger of building in such areas is groundwater pollution, which occurs when pesticides and other contaminants rush into the water supply. - LoudounExtra
In 2003, the Board of Supervisors adopted regulations that limited development in limestone areas as part of a broad plan to slow growth in Loudoun, one of the nation's fastest-growing counties. But a year later, the Virginia Supreme Court threw out the plan on a technicality.So not only did the previous Board leave us with lawsuits and budget deficits, but also actual, physical holes in the land itself caused in part by rampant development. We should keep these issues in mind as we evaluate the job the current Board of Supervisors is doing. This Board has done a remarkable job so far cleaning up the mess they inherited, up to, and including sinkholes.
The supervisors who took over the board that year generally supported the growth and rejected limits on development in limestone areas. Last year, in the waning weeks of the pro-growth supervisors' term, the members reversed course and said they would support some regulations governing construction in the limestone area. - LoudounExtra
The current board, which supports a slower rate of growth, today is scheduled to consider new regulations for the county's limestone area. Under the proposed rules, builders would have to take steps to minimize the risk of sinkholes, and homeowners would have to be educated about the danger of groundwater contamination.One could be forgiven for thinking that "house goes down a sinkhole" was only a metaphor for the mortgage crisis, but here in Loudoun, it could be both metaphor, and reality.
"It is one of our most sensitive geographic areas. We have historically seen an increase in sinkholes as development has gone on in the corridor," said Supervisor Sarah R. "Sally" Kurtz (D-Catoctin), whose district includes most of the limestone area. "It's a matter of preventing property loss — as in, your whole ... house goes down a sinkhole." - LoudounExtra