BUCHANAN COUNTY, Va. (WJHL) — After the second bout of severe flooding in a year left more than 100 structures damaged across Buchanan County, southwest Virginians are left wondering why exactly the county is prone to such disasters.

In press briefings with Virginia Department of Emergency Management (VDEM), officials stated that 2022’s flooding was caused by heavy rainfall paired with geography that creates severe situations.

An area’s flood potential is actually a relationship between precipitation and drainage, measures of how quickly water enters the area and how quickly it leaves the area. In Buchanan County’s case, extreme precipitation overwhelmed drainage infrastructure before it stood a chance.

“I can’t speak to the drainage in the county,” VDEM communications staff told WFXR’s sister station, WJHL. “But even the best drainage systems in the world would have a hard time catching up with the estimated 5.5″-6.5″ that fell in that area over the course of just 3 hours, and most of it was actually in 2 hours.”

That 2-hour estimate comes from National Weather Service measurements, which means that much of the water that fell Tuesday night was racing down the mountainsides of Buchanan County before the clock had even struck midnight.

Mountain runoff is what keeps the streams and rivers in the area alive, but when the volume of rain sees such a dramatic spike, those sources of drinking water and fishing fun become extremely destructive.

“We really do not have any wide valleys in the areas where rivers and creeks run through,” said Buchanan County Attorney and Floodplain Manager Lawrence Moise. “Thus when we get a tremendous volume of rain over a very short period of time in one particular area of the county, we have flash floods.

For Buchanan County residents, flooding isn’t a new occurrence. In fact, Virginia flooding maps show large swaths of the county’s developed land placed squarely in level A flood zones, meaning that the land has a 1% chance of flooding each year according to the Federal Emergency Management Agency (FEMA).

Emergency officials are still tallying the full impact and scale of the floods, but early estimates included dozens of destroyed or damaged buildings with only one major injury: a snakebite. Virginia Gov. Glenn Youngkin’s office told WJHL that the results of those damage assessments will help him determine whether to request federal aid.