Beyond major: Cruso depth dwarfs 2004 figures
Though Tropical Storm Fred bears the brunt of the blame for last week’s flood, a cold front moving ahead of the tropical storm set the table for destruction.
“When the moisture associated specifically with Fred moved in Tuesday afternoon, the soils were primed. The rivers were already starting to respond,” said National Weather Service Meteorologist Trisha Palmer.
The official NWS station in Asheville reported a total 3.43 inches of rain Aug. 15-16, with Fred’s arrival Aug. 17 bringing an additional 3.3 inches. Prior to rains from Fred, the Greenville-Spartanburg Forecast Office reported a weekend flash flood in Charlotte and an especially damaging one in Transylvania County Monday, Aug. 16, with the Upper French Broad at Rosman reaching major flood stage.
Between 8 a.m. Sunday, Aug. 15, and 8 a.m. Wednesday, Aug. 18, locations across the region received 5-10 inches of rain, but along the Transylvania-Haywood County line totals reached 10-15 inches, with the gauge closest to Cruso reporting 14 inches during that time period.
“It was an incredible amount of rain,” said Palmer.
While the Cruso area undisputedly received the worst of the flooding in Western North Carolina, it did not receive the worst of the rainfall. Multiple gauges on the Transylvania/Jackson County line recorded more than 20 inches during the same 72-hour time period, Palmer said.
However, those areas didn’t see major flood damage, because the heaviest rainfall was concentrated right along the Eastern Continental Divide. Instead of all flowing into a single watershed, some of it flowed into the Upper French Broad watershed headed toward Brevard while some flowed south toward Lake Toxaway and South Carolina.
“If it had fallen just a little bit further north or a little bit further south, it would have all fallen into one basin and been funneled down in one direction,” said Palmer. “It would have been an incredible flood wave. It was already incredible, but it would have been even more incredible.”
As it is, Jackson County saw only minor flood damage, said Emergency Management Director Todd Dillard. One home in the Canada community received considerable damage, and there were a few minor landslides with the typical flooding on Ashe Settlement Road in Webster.
Jackson County, especially in the northern end, has the additional buffer of the Duke Energy reservoir at Lake Glenville. Emergency services gets a heads-up before Duke spills water from the dam.
The rains in Cruso all fell into one watershed, and the East Fork Pigeon River — which under normal conditions looks more like a creek than a river — absorbed it all.
The closest U.S. Geological Survey gauge to the ravaged communities is located about 1 mile southeast of Jukebox Junction, 5 miles from Cruso. There’s no way to track exactly how fast the water rose in the most affected areas, but the gauge gives a clue.
At that site, the water rose nearly 8 feet in two hours between 3:45 and 5:45 p.m., when it crested at an incredible 16.15 feet. For that site, major flood stage — the stage at which people should stop worrying about their property and start worrying about their lives — is 12 feet, reaching a record 13 feet in 2004.
The flood didn’t crest in Canton until hours later, at 8:15 p.m. While the reading of 19.76 feet easily surpassed the 19-foot major flood stage marker, it did not best the 22.8-foot record set in 2004. However, said Palmer, despite the 3-foot difference emergency management is reporting that the damage is just as bad as that in 2004.
“That’s telling us a lot about changes in the development across the area,” she said. “There’s been a lot more development in the area in the past 15, almost 20 years. So there’s maybe a lot more concrete across the area. Maybe the river basin has changed.”
Now, the Weather Service is considering whether it needs to make any changes to its forecast system, such as revising flood stage markers.
“We can predict the weather, but we can’t predict people and land use,” Palmer said.
Even predicting the weather is more challenging in the mountains, where topography often blocks radar and the slopes and ridges create microclimates that complicate the forecast. Observations from the volunteer Community Collaborative Rain, Hail and Snow Network — known as CoCoRaHS — help the National Weather Service better understand climate and weather patterns in these hard-to-reach places. To join the network, visit www.cocorahs.org .