Monthly Water Resource Summary

August, 2017

Precipitation

For August 2017, Indiana’s precipitation was generally below normal, with average temperature below normal. The statewide monthly precipitation average was approximately 63.5 percent of normal. The overall monthly temperature average for Indiana was 70.3 degrees Fahrenheit or 1.9 degrees below normal.

All nine climate divisions received well below normal precipitation for the month of August. The north-central climate division received the highest (76.4) percentage of normal precipitation for the month, while the south-central received the lowest (53.0) percentage.

For the year to date, eight of the nine climate divisions have received above normal precipitation, ranging from 98.7 percent of normal for the southwestern climate division to 134.6 percent of normal for the northeastern climate division.  For the 2017 water year, which began October 1, 2016, total precipitation is above normal for seven of the nine climate divisions (89.6% to 123.3% percent of normal). Beginning January 2016, all climate divisions have received above normal precipitation. These range from 101.1 percent for the southwestern division to 115.6 percent for the northwest division.

The Standardized Precipitation Index (SPI) long-term 12-month indices shows the northeastern climate division in the extremely wet category; the northwestern, north-central, central, east-central, and southeastern climate divisions in the “moderately wet” category; and the remaining three climate divisions are in the “near normal” category. The 6-month SPI indices shows the northeastern, central, east-central, and southeastern climate divisions in the “very wet” category; the northwestern, north-central, and west-central climate divisions are shown in the “moderately wet” category; and the remaining two climate divisions are in the “near normal” category.  The 3-month SPI indices shows the central climate division in the “moderately wet” category; and the remaining climate divisions are in the “near normal” category. The 1-month SPI indices shows the central, east-central, southeastern, south-central, and southwestern climate divisions in the “moderately dry” category; and the remaining climate divisions are shown in the “near normal” category.

U. S. Drought Monitor

For the period ending August 29, 2017, the U.S. Drought Monitor shows abnormally dry conditions in the west-central and the north-central portions of the state.  No other drought conditions exist in the state.  The U.S. Seasonal Drought Outlook does not predict drought conditions through November 30, 2017.

Streamflow

Of the twelve streams included in drought reporting since 1999, eight had stream flow at normal or well above normal and four had stream flow well below normal.  The Muscatatuck River near Deputy had the lowest mean monthly flow at 20% and the Whitewater River near Alpine had the highest mean monthly flow at 189%.

Detailed Information on Streamflow

Lake Michigan

The Lake Michigan-Huron water level for September 1, 2017 was seven inches above the measurement taken on September 1, 2016, and one inch below the measurement taken on August 1, 2017.  On August 31, 2017 the Michigan-Huron level was 580.62 feet, which is approximately 47 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 17 inches above the average. All Lake Michigan-Huron data are referenced to the International Great Lakes Datum 1985.

The U.S. Army Corps of Engineers predicts the Lake Michigan-Huron water level to fall two inches over the next month. 

Reservoirs

The water levels in five of the eight Indiana reservoirs being monitored by the U.S. Army Corps of Engineers were at or above the normal pool elevation on August 31, 2017. The normal pool deviation ranged from -0.6 feet (Monroe) to 2.6 feet (Patoka). 

All three reservoirs monitored by Citizens Water were above their respective normal pool elevations as of August 31, 2017. The deviation from normal pools ranged from 0.07 feet (Morse) to 0.80 feet (Eagle Creek).

Groundwater Levels

As of August 31, 2017 new water level data was available for all of the nine wells currently monitored. Of the nine wells monitored, data indicate the groundwater level for La Porte 9, Fulton 7, LaGrange 2, and Clark 20 are below their respective mean monthly level. The mean monthly groundwater levels are above normal for Vigo 7 and Morgan 4 and near normal for Randolph 3, Posey 3, and Harrison 8.  

Real-time data are available for all nine observation wells. The real-time information may be accessed on the following U.S. Geological Survey website: http://waterdata.usgs.gov/in/nwis/current/?type=gw

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