KNOXVILLE, Tenn. (WATE) — Portions of Sevier County received heavy rain Tuesday night as thunderstorms passed over the foothills of the Smoky Mountains. The Greenbrier campground flooded, forcing evacuations and water rescues.

How much rain fell? Not as much as you might think. First, know that rainfall totals in the Greenbrier Campground area are only estimates, as there is not an official rain gauge in that area.

Sevier County’s Assistant Mayor Perrin Anderson said Wednesday morning that over 8.5 inches of rain fell in the Greenbrier Campground area between 8-10 p.m. Radar analysis from the National Weather Service and the WATE 6 Storm Team indicate lower rainfall totals.

Radar estimates show about 1.5 inches of rain fell near the Greenbrier Campground on Tuesday.

The WATE radar forecast from Tuesday evening.

Runoff from higher elevations

It is important to note that Greenbrier Campground is located at a very low elevation. Radar estimates indicate that higher elevations near the campground saw close to 3 inches of rainfall.

As a result, heavy rainfall from surrounding areas likely flowed downward into the campground and contributed to the flash flooding. The rain combined with runoff from nearby higher elevations and resulted in flash flooding at the Greenbrier Campground in the Great Smoky Mountains National Park.

The national park tracks monthly rainfall averages on a website, where they note that 5.7 inches is average for July for locations near Gatlinburg.

Saturated ground

More than 5 inches of rain has fallen over the last week, meaning the ground was already saturated when the storm cell produced flash flood conditions along the Middle Prong of the Little Pigeon River.

The park service said they recorded 8.72 inches of rainfall within several hours around 9 p.m. in the Porters Gap area.

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It is also important to remember that the campground is located near the West Prong of the Little Pigeon River, which places it at a higher risk for flooding.

Code Red Alerts

Code Red alerts went out to subscribers around midnight alerting to flooding in the area, Perrin said. These alerts can be sent through voice, text, or email, but Anderson noted that cell service in the campground is spotty – as it is in most locations near the national park.

The Flash Flood Warning for the area was expired by the National Weather Service at 2:31 a.m. Wednesday morning, about 45 minutes earlier than anticipated as there were no ongoing reports of flooding.

Anderson says that multiple agencies responded last night to help rescue people who were stranded on higher ground because of the approaching floodwaters. First responders carried life preservers to people and then escorted them out of the impacted area. No boats were required for rescues, he said.

EDITORS NOTE: This story has been edited to include information provided by the National Park Service.