Record rain fell in Tennessee, USA on 21 August, 2021 causing catastrophic flooding. A state of emergency is in effect for Dickson, Hickman, Houston and Humphreys counties.
Humphreys County is the worst affected area. The National Weather Service (NWS) in Nashville said a record 17 inches (432 mm) of rain fell in the county on 21 August. Officials reported 10 people have lost their lives and approximately 40 people are missing or unaccounted for. Rural roads and highways have been ripped up or washed away and a large section of Interstate 40 was closed temporarily. Power, water and telecommunications infrastructure has also been damaged or destroyed. More than 4,000 customers were without power across the affected areas, including 3,500 in Humphreys County.
Several shelters have been opened to assist survivors, while emergency crews continue to search for those reported missing. Fire and Emergency Management teams from the local area along crews from Nashville are assisting with rescue and relief operations. The Tennessee Helicopter Aquatic Rescue Team and the Tennessee National Guard were also deployed. Rescue operations have been hindered by damage to roads as well as power and telecommunication outages.
“Our first priority is to assist with getting responders access to the area and conduct rescue operations,” said Maj. Gen. Jeff Holmes, Tennessee Adjutant General. “We’ll continue to increase the number of forces as the situation dictates and we’ll be positioning additional specialty units to respond as needed. This is all about agility and teamwork with trusted agency partners and we’re fortunate to have those relationships developed through many hours of training together.”
Flooding also damaged roads in Dickson County. Emergency crews carried out 11 high water rescues in the City of Dickson.
Record Rain and Rivers
Some areas recorded 9 to 10 inches of rain in the first 12 hours of 21 August, including Lyles with 10.02 inches (254.5 mm); Nunnelly 10.03″ (254.76 mm) and Centerville 9.21″ (233.93 mm).
NWS Nashville said a preliminary 17.02 inches (432.31 mm) of rain was measured at McEwen in Humphreys County in 24 hours on 21 August, adding that this “likely broke the all-time 24 hour rainfall record for the state of Tennessee, which was 13.60″ (345.44 mm) in Milan set on September 13, 1982.”
The Piney River also broke record levels, NWS Nashville reported. The river gauge on the Piney River at Vernon in Hickman County measured 31.8 feet on 21 August, shattering the river’s previous record high of 20.08 feet set in 2019.
The increase in levels of the river was nothing short of dramatic. As of 01:00 on 21 August the Piney River at Vernon stood at 3.3 feet. By mid-morning 11.15 the level had jumped to over 31 feet and well above Major Flood Stage of 24 feet.