Managing Summer Flows

Each summer, TVA’s reservoirs abound with recreational opportunities. From boating and fishing to the businesses that depend on a thriving lake season, reservoirs play an important role in the daily lives of those who call the Valley region home.

This year, reservoir levels look a little different – and there’s a clear reason why. The region is experiencing drought conditions that mirror some of the driest years on record.

And despite lower levels, the reservoirs are still available to safely enjoy.

“The reservoir elevations are lower than average years because we haven’t seen rainfall. But the biggest thing is that the lakes are still open and fully usable,” Benjamin Heath, operations support manager at TVA’s River Forecast Manager, said.

Benjamin Heath, operations support manager at TVA's River Forecast Center.

The Spring Fill

As part of its mission to balance the Tennessee River system for benefits including flood control, navigation, water quality and recreation, TVA relies heavily on spring rainfall to fill its reservoirs.

In an average year, the Valley region receives about 51 inches of rain.

But as of April, the region faces varying levels of drought, and some areas will need significantly more rainfall to reach normal summer elevations.

And it’s not just rainfall that impacts the region. Runoff, which also replenishes the reservoir levels, is lower this time of year due to evaporation, rising temperatures and new foliage.

For CY 2026, rainfall and runoff are at 74% and 45% of their normal levels, respectively. As a result, some reservoirs will sit lower than usual heading into recreation season.

Nickajack Dam in southeast Tennessee.

Navigating the Seasons

By working with partners at the National Weather Service and leveraging advanced forecasting tools and decades of experience, TVA identified this dry season early on and moved quickly to lessen its impact.

“We were very aggressive early in the year and started holding back water earlier than normal to get the reservoirs up,” Heath said.

On a typical year, TVA begins filling its reservoirs around mid-March. But this year, the River Forecast Center began collecting runoff as early as February.

“It was all about opportunity,” Heath said. “As rain fell, we would hang on to it.”

And being proactive paid off, allowing reservoirs to get most of the way toward summer pool levels.

Behind these decisions is a comprehensive policy developed over 20 years ago that serves as a guiding compass to manage the river system through dry and wet years.

The policy has successfully guided operations through past droughts, including the record‑breaking dry seasons of 2007 and 2008.

Every five years, it is reviewed by the Resource Stewardship Council – an advisory group made up of public interest groups like marina owners, farmers, business owners and experts from universities and state agencies.

“Whenever we present, they say, ‘Keep doing what you’re doing.’ This policy still serves us well,” Heath said.

Darrell Guinn, River Forecast Center senior manager.

Managing the Flow

Following this plan, TVA will continue monitoring rainfall, runoff and weather patterns, and controlling release rates to support the ecosystem.

Even in dry years, TVA must release water in some capacity to keep the ecosystem healthy, Heath said.

“A healthy downstream provides water supply to 5.2 million people. We’re not going to sacrifice that,” he said.

It’s all part of operating a complex river system that benefits more than 10 million residents across seven states.

This season, Heath encourages lake visitors to exercise caution, as lower elevations can expose hazards such as stumps, rocks or shallow areas near the shoreline, which are normally underwater.

Despite the lower water levels, the lakes are still open and TVA will continue managing this world-class resource through rain or shine.

“These large reservoirs serve many purposes – reducing floods, keeping habitats healthy and providing consistent water supply," Heath said. “They’re also important for recreation and the regional economy.

“You’ll have wet years and you’ll have dry years. That’s part of managing a system that relies on Mother Nature. But our goal is always to keep the Valley region’s needs in balance."

The River Forecast Center in Knoxville, Tennessee.

An aerial view of Interstate 24 over Nickajack Reservoir.