News Center
Irma Blows Through, but Lake Lanier Level Barely Budges

Posted on: Sep 15, 2017

As Tropical Storm Irma slammed metro Atlanta with heavy winds, the region’s water planners watched the storm closely to see if the rains would help refill Lake Lanier.

Unfortunately, the lake increased by just five inches between Sept. 10 and Sept. 14. Lake Lanier, the region’s primary source of water, remains about 5.5 feet low, following the 2016-17 drought.

What happened?

  • In metro Atlanta, the heaviest rains associated with Irma fell below Lake Lanier
  • Gainesville, just north of the lake, received 0.88 inches of rain, according to the National Weather Service
  • In contrast, Peachtree City got soaked with more than 4 inches of rain, also according to NWS

The bottom line

Because Lake Lanier relies on a small watershed and is so large, it takes a significant amount of rainfall to fill up.

Conservation remains critical, as the lake has yet to fully recover from the 2016-17 drought. At its low point, the reservoir was about 11 feet below full pool and is still about 5 feet low.

We must all continue to do our part to use water wisely. Visit to learn tips for conserving water inside and outside the home.

The following map shows rainfall totals from Irma:

  • The darker blues and purple depict the heaviest rainfall amounts
  • The lighter yellows show the lightest rainfall — an area that includes Lake Lanier and its watershed
  • The map shows a 72-hour period ending at noon on Sept. 14

Irma Rainfall Map


Lake Lanier Levels, in feet:

Sept. 10:   1,065.2
Sept. 11:   1,065.43
Sept. 12:   1,065.54
Sept. 13:   1,065.58

Source: U.S. Army Corps of Engineers

Related Stories:

As Irma Raged, ARC Helped Keep Older Adults Safe
A Storm is Coming. Are You Ready?
State Eases Watering Restrictions in Metro Atlanta