Tennessee River Valley Sets New Rainfall Record In 2020

This has been the wettest year in the Tennessee River Valley for at least 131 years, according to the Tennessee Valley Authority (TVA).

TVA determined that the valley set a rainfall record with 67.43 inches as of December 13, surpassing the old record of 67.0 inches set in 2018.

The 2019 year was the third wettest year on record.

“The last three years have been a remarkable stretch of above-average rainfall,” said James Everett, senior manager of TVA’s River Forecast Center. “Before 2018, the previous record had stood for 45 years. Since 2018, we’ve either set a record or come close to it every year. And the 2020 record comes with two weeks left in the calendar year, so it will likely increase. Also, between October 1, 2019, and September 30, 2020, the Tennessee Valley recorded 75.74 inches of rainfall.  This was the wettest fiscal year total ever in the 131-year period of record.” 

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The above-normal runoff from rainfall has persisted throughout the entire year, with one notable exception: the 2020 record comes after a month of below-average rainfall just last month. November rainfall in the Tennessee Valley totaled 2.34 inches, which was only about 62 percent of normal monthly rainfall. That shortfall ended a streak of 13 straight months of above-average rainfall, which is also a Tennessee Valley record.

This year, TVA has worked to avert about $1 billion in flood damages throughout the valley, keeping several cities from being submerged, according to a TVA news release.  Each year, TVA’s reservoir management saves the region about $300 million, the agency estimated. TVA has averted more than $9 billion in flood damages since it completed its first dam, Norris Dam, in 1936.  

Throughout the record rains, TVA has used its 49 dams to manage lake levels and river flows to balance the competing demands of the reservoir system, including flood control, navigation, hydroelectric generation, recreation, water quality and water supply.

”Managing the Tennessee River system during this extended period of record rainfall continues to be a team effort of the River Management, Hydro Generation and Dam Safety staff at TVA,” Everett said. “The sites and crews in the field have put in countless long days maintaining and operating equipment like sluice gates, spill gates, cranes and, of course, hydroelectric generators, which are all necessary to control flow through TVA reservoirs.”