In case you were wondering, we ended the month of May 2018 with 11.42 inches of rainfall here at Peeper Pond Farm. That’s a little more than three times the 30-year average total rainfall for the month of 3.78 inches. We ended up receiving an inch or more of rain on four days, one of which dumped a total of 2.90 inches! As you might expect, we were hoping for some relief now that the month has officially ended. Good luck with that.
So far, after the first 3 days of June, we have received an additional 4.70 inches, 4.65 inches of which fell over the past 36 hours. The 30-year average rainfall for June in our area is 3.13 inches, so we received 1.5 inches more than the entire monthly average in the first three days of the month. After the soaking we received in May, the ground was too saturated to absorb the deluge. Although we sustained no significant damage here at Peeper Pond Farm, the river and stream flooding that resulted washed out roads throughout our area, as illustrated in the pictures accompanying this post. Numerous mudslides also occurred, including one that closed a section of U.S. Route 220 south of Moorefield. Barb and I toured our immediate area and discovered that portions of four important roads in our area were closed due to high water or washouts—U.S. Route 220, Greenwalt Gap Road, Mozer Road (formerly Brushy Run Road), and North Mill Creek Road. Every road we travelled had some areas where runoff from individual properties and driveways flowed across our path.
Many young people will be quick to call this storm event a “500-year flood.” However, our old-timers will remember that the 1985 Election Day flood was far worse. That epic flood was spawned by the remnants of Tropical Storm Juan and left record-high watermarks when the South Branch of the Potomac River spilled over its banks and wiped out Franklin, Petersburg, and Moorefield. Pictures and stories of the devastation would simply take your breath away.
I wasn’t living in West Virginia during the 1985 flood, but I do recall the most devastating flood that occurred in any place I have ever lived—the 1994 flood in Central Georgia. At that time, I was the Planning Director for the Middle Georgia Regional Development Center in Macon. The storm, which was caused by Tropical Storm Beryl, washed out the Lake Wildwood dam and flooded the city’s water plant. Everyone in the immediate Macon area lost public water service for 23 consecutive days while the mud and debris that buried the water treatment system was removed and the water lines were flushed. National Guard stations were set up across the city to distribute bottled water to affected residents. Just driving around the city made one feel as though it had fallen under Marshall Law.
I clearly remember how frequently the term, “500-year flood”, was used to characterize that flood. At the peak of the flooding, Emergency Management Agency and Army Corps of Engineers officials descended on our office to evaluate the extent of the flooding. They had taken helicopter aerial photos of the floodwaters and wanted to compare them directly to the Flood Insurance Rate Maps using our new computer-based Geographic Information System. They scanned and digitized their aerial photos and overlaid them on the digital flood maps to see how they compared to the official floodplain boundaries. The results of that comparison were amazing. As the officials compared the data, they noted how far the floodwaters extended beyond the 100-year floodplain lines in many areas. However, I noticed a number of areas where the alleged 500-year floodwaters didn’t even reach the 100-year floodplain lines. When I pointed that out, the officials agreed it was interesting, but they offered no explanation for it. They simply said, “well, we have to call it something.”
In the years that have passed since that historic Macon flood, I have had many opportunities to think about that analysis. If you think carefully and critically about it (a truly lost art these days), you will realize that we don’t have enough accurate historic weather records to know what a 500-year flood would be. The Commonwealth of Virginia (from which West Virginia was carved in 1863) was first settled permanently at Jamestown in 1607. That was 411 years ago now, and our area (Pendleton County) was not first settled until 1737 (130 years later). This means that historic weather data in our country has yet to span the first 500 years of our settlement, assuming accurate, comprehensive weather data began at first settlement, which is a very shaky assumption at best.
You must also consider the fact that any biggest flooding conditions in the first 500 years may or may not be representative of 500-year floods in prior 500-year periods. The word “average” means the average of all floods over a large number of 500-year historic periods. If you only have accurate data for one 500-year period, how can you even argue it is representative of the floods that may have occurred in prior 500-year periods? The fact of the matter is that, even after we have kept 500-years’ worth of flooding records, we have no way to say that the biggest flood that occurred during that period is representative of an average 500-year flood. That’s one of the important theoretical quandaries that we face when we discuss climactic data.
There’s no doubt that the flooding we experienced in Pendleton County over the past month will be remembered for decades to come. It will become one of the stories that define what it means to be a grandparent. However, it also should remind us of the awesome power of nature and how unpredictable it can be. Hopefully, we don’t need too many more experiences like this to learn that.