Monthly Water Resource Summary

August 2024

Precipitation

August 2024 Indiana precipitation was below normal, with average temperature slightly above normal. The statewide monthly precipitation average was 74.4 percent of normal. The overall monthly temperature average for Indiana was 73.3 degrees Fahrenheit or 0.6 degrees above normal.

All nine climate divisions received below normal or much below normal precipitation for August (see Percent of Normal Precipitation Table). Climate Division 8 (SC) received the highest (89.5) percentage of normal precipitation for the month, while Climate Division 7 (SW) received the lowest (55.8) percentage.

Precipitation for the year to date (2024) ranges from 92.7% to 117.1% through August. For the Water Year 2024, two of the nine climate divisions received above normal precipitation, ranging from 80.8% to 108.5%. Over the 2-year period (from September 2022-August 2024) all nine climate divisions have received below normal precipitation ranging from 82.4% for Climate Division 6 (EC) to 94.9% for Climate Division 3 (NE).

The 12-month and 3-month SPI indices show all climate divisions in the “near normal” category.    The 6-month SPI indices show climate divisions 1 (NW) and 2 (NC) in the “moderately wet” category; with the remaining climate divisions in the “near normal” category. The 1-month SPI indices show Climate Division 7 (SW) in the “moderately dry” category; with the remaining climate divisions in the “near normal” category.

• Table of recent precipitation compared to normal for each climatic division of the state.
• Standardized Precipitation Index (SPI) drought maps for the state for current month.
• Explanation of Standardized Precipitation Index (SPI)

U. S. Drought Monitor

For September 3, 2024, the U.S. Drought Monitor shows that most of the state is experiencing “abnormally dry” or “moderate drought” conditions except for a wedge from west-central to central Indiana. The U.S. Seasonal Drought Outlook predicts drought is likely to develop for all but the northwest corner of Indiana by the end of November 2024.

• State Map
• Latest U.S. Drought Monitor Map for the United States 
• Learn more about the U.S. Drought Monitor 

Streamflow

In August 2024, only one of the streams included in drought reporting since 1999 had above normal stream flow.  The St. Marys River at Decatur had the lowest mean monthly flow at 23%, and the Kankakee River at Shelby had the highest mean monthly flow at 101%.

Detailed Information on Streamflow

Lake Michigan

On August 30, 2024, the Lake Michigan-Huron forecasted water level was 3 inches below the measurement taken on July 30, 2024, and 2 inches below the measurement taken on August 30, 2023. On August 31, 2024, the Michigan-Huron level was 579.56 feet, which is about 35 inches above the lowest recorded monthly mean level for August set in 1964. Comparison of August monthly mean water levels to the long-term (1918-present) average shows Lakes Michigan-Huron water levels were about 4 inches above the average. All Lake Michigan-Huron data are referenced to the International Great Lakes Datum 1985.

The Lake Michigan-Huron water level is forecast by the U.S. Army Corps of Engineers to fall three inches over the next month.

Reservoirs

On August 30, 2024, the water levels for three of the eight reservoirs monitored by the U.S. Army Corps of Engineers were above normal pool elevation. The deviation from normal pool ranged from -1.5 feet (Patoka) to +0.5 feet (Brookville).

Two of the three reservoirs monitored by Citizens Water, Eagle Creek and Morse, were above their respective normal pool elevations as of August 30, 2024. The deviation from normal pools ranged from -0.28 feet (Geist) to +0.53 feet (Eagle Creek).

Groundwater Levels

As of September 2, 2024, new water level data is available for all nine wells currently monitored. Of the nine wells, data indicates that water levels are below normal for Laporte 9, Fulton 7, Lagrange 2, Vigo 7, Morgan 4, Randolph 3, Posey 3 and Harrison 8. Clark 20 is currently near normal.

Real-time data is available for all of the wells and may be accessed on the U.S. Geological website.

• Detailed information on groundwater levels

Acknowledgments
This report has been compiled from Division of Water data and from information supplied by the following:

Precipitation data:
National Oceanic and Atmospheric Administration, National Weather Service, Midwestern Regional Climate Center

Standardized Precipitation Index (SPI):
National Drought Mitigation Center (NDMC) and Western Regional Climate Center (WRCC)

Streamflow:
U.S. Geological Survey and State of Indiana cooperative program

Lake Michigan level data:
U.S. Army Corps of Engineers, Detroit District

Reservoir data:
U.S. Army Corps of Engineers, Louisville District

Groundwater level data:
U.S. Geological Survey and State of Indiana cooperative program

Temperature data:
Midwestern Regional Climate Center and Indiana State Climate Office, Purdue University