TVA Handling Above Average Rainfall During Fall of 2018

TVA River Management teams handled above average rainfall and runoff across the Tennessee Valley in fiscal year 2018. That trend continues to be the norm so far in fiscal year 2019 (which started on Oct. 1), with nearly 4 inches of rainfall last week across parts of the Valley and more on the way.

Through the first two weeks of November, in the area above Chattanooga, rainfall totaled more than 3 inches, which was 2 inches above normal. Fiscal year to date runoff was 2.4 inches, about 1.1 inches more than normal. TVA’s conventional hydro generation was more than 118% of normal.

dam spilling

This week, the rains continued. Today (November 13), all TVA main river dams are spilling. The river management and hydro generation teams are working closely day and night to coordinate the spilling, flood prevention and heavy flows with power generation and outages at some hydro plants. Engineers in the River Forecast Center along with Hydro Dispatch operators in the System Operations Center also coordinated temporary flow reductions from tributary dams like Watauga, Norris, Cherokee and Douglas in order to reduce flows into the main-stem Tennessee River.

The 3-day rainfall forecast calls for an additional up to 1-2 inches of rainfall across the Tennessee Valley, with heavier amounts possible in the mountains of North Carolina and Georgia.

Managing ample rainfall has been nothing new for the past year for TVA. After an abnormally dry January 2018, rainfall and runoff during winter, spring and summer this calendar year tracked above normal and continues this fall.

Western Valley rainfall (11.6 inches) during February 2018 was so high that it broke the previous February record for rainfall that dated back to 1939. In August 2018 rainfall and runoff reached about 115% of normal. Hydro generation was about well above 100% of normal and continues at about 116% of normal so far this calendar year.

TVA also managed above average rainfall in September and early October from hurricanes Florence and Michael, which provided a boost to hydroelectric generation during a period of abnormally high air temperatures and power demand.

TVA manages the 652-mile Tennessee River and its many tributaries using a series of 49 dams to meet vital public needs in six key areas: navigation, flood damage reduction, power production, water quality, water supply, and recreation.