Center's Research Gives Insight Concerning Local Lake Flooding

Release Date: 7/24/2015
Contact Information: Madisson Heinl, 574-372-5100, ext. 6446, heinlmm@grace.edu

Center's Research Gives Insight Concerning Local Lake Flooding

WINONA LAKE, Ind. – An emergency order to restrict watercraft operations on specified lakes in Kosciusko County was filed Friday, July 17. This ordinance went into effect on Lake Wawasee, Lake Tippecanoe, and the Barbee lakes chain and is in effect until further notice from the Indiana DNR.

Flooding and high water levels continue to be county-wide issues this summer. Many questions have been raised by community members regarding when specific lakes will re-open for high-speed boating activity. While it is impossible to speculate or make predictions on when these restrictions will be lifted, recent local lake research can give some context to these issues and offer some guidance.

The Center for Lakes & Streams conducted a three-year study (2011-2013) on lake levels on Wawasee and Syracuse lakes. Based on the research gathered from that study, it is known which inflows and outflows are most important to Wawasee and Syracuse lakes. Major inflows included precipitation falling directly on the lake surface and inflowing streams. Major outflows included evaporation of water from the lake surface and stream outflow through the Syracuse dam. Groundwater (springs on the lake bottom) sometimes flowed into the lake and sometimes flowed out of the lake. Current stream sampling by the center offers additional guidance.

According to the previous study, Kosciusko County lakes can lose about one quarter inch of water each day during the month of July due to evaporation. Springs can flow into the lakes or out of the lakes depending on groundwater levels, and it is likely that groundwater is currently flowing into local lakes due to previous rainfall. The rate of groundwater inflow was found to be up to one third of an inch of water each day in Lake Wawasee during 2013.

From current stream sampling conducted by the Center for Lakes & Streams, water inflows to local lakes from streams peaked 4-6 days ago and have been lessening since then. At their peak, there was about 25 million gallons of water entering Lake Wawasee from inflowing streams each day, which would lead to a quarter of an inch lake level increase. At the same time, only 15 million gallons were leaving Wawasee and Syracuse lakes over the dam as stream outflow each day. Stream and groundwater flowing into these lakes overwhelmed evaporation and dam outflows such that the water levels rose to the highest recorded levels in over 30 years.

Assuming there is no precipitation over the next few days and there are significant decreases in stream and groundwater inflows, it is possible that Lake Wawasee could lose a quarter to a half inch of water each day due to evaporation and the outflow through the Syracuse dam.

According to Dr. Nate Bosch, the director of the Center for Lakes & Streams, “Reducing the lake water level in Wawasee and Syracuse lakes just an inch, requires a loss of 104 million gallons of water. So we need to lose a huge amount of water to see a substantial change in water levels.”

The excess of precipitation this summer can mean many things for our local waterbodies. Flood events that bring large amounts of rain to local lakes and streams can also wash excess nutrients and other substances into the lakes, causing weeds and algae to grow and therefore decreasing the clarity and overall health of the lake, especially when paired with warmer temperatures.

The Center for Lakes & Streams has been collecting samples from local lakes and streams since late May. These samples will be analyzed within the next few months and the effect of this summer’s precipitation will be better understood.

The Center for Lakes & Streams at Grace College conducts applicable research, engages and educates residents, and collaborates with other organizations in efforts to make the lakes and streams of Kosciusko County cleaner. For more information or to support their efforts, visit lakes.grace.edu.

                                                             ###