The contributer of the article below, Dr. Nathan Bosch, heads up Grace College’s Kosciusko Lakes and Streams (KLAS) and is an appreciated and important partner to WACF. Lake research and providing county-wide lake information has been critical to WACF’s Ecology and water testing program as well as Education and outreach.
KLAS is a community-based research center at Grace College focused on applied research, educational outreach and advocacy that builds community capacity to promote, enjoy and properly steward Kosciusko County’s lakes and streams.
- Collect and analyze local lake and stream data
- Engage adults and children in water education
- Partner with businesses, nonprofit organizations and government agencies to improve and protect the lakes and streams
- Train college science students and teacher education students with skills for their future careers in science and teaching
Of the important issues, one of WACF’s concerns includes local water resources and the influence on human health. A KLAS study identifies E. coli and microcystin (blue-green algae toxin) as current lake-related human health threats to residents of Kosciusko County. Long-term, weekly E. coli sampling at seven public swimming beach sites by the Kosciusko County Health Department was confirmed to be an important endeavor to protect the public. Monthly microcystin sampling by KLAS in 2010 and 2011 showed only four of 44 lakes sampled had no microcystin detected during the study; there were 14 lakes that had elevated microcystin levels including Wawasee.
Drought to Flood
By Dr. Nate Bosch, Kosciusko Lakes and
Streams, Grace College
Water levels of our lakes
It was only a few months ago that inquiries about low water levels and drought prompted me to write a letter to many Wawasee and Syracuse lake residents that explained the science of lake levels. Now, I am receiving questions about flooding and how such a quick turn of events is possible. To answer these questions I’ll review: influences on lake levels, geographical and historical context to the past two years, and field data we have recently collected on Lake Wawasee that confirms these observations.
Lake level Influences:
Precipitation – The timing and amount of precipitation contributes to the water level in a lake. This effect is altered by watershed size and current soil moisture conditions.
Evaporation – The rates of water evaporation increase with warmer temperatures. Also, warmer temperatures in the winter months lead to less ice formation, which allows evaporation during winter months as well, rather than sealing off the lake under ice.
Groundwater – Lakes can be classified as “gaining” or “losing,” depending
on whether groundwater is entering or leaving the lake basin at a given time. This is caused by the relation of the local water table to the water level in the lake basin. Springs flow into the lake under gaining conditions and out of the lake during losing conditions.
Human Activities – Water withdrawals related to irrigation, lake level control structures (i.e. dams) and dredging (by opening up new channels of water loss from the lake basin) influence lake levels as well.
Geographical and Historical Context :
The geographical and historical context for the wide swing in lake levels on Lake Wawasee from low to high is not unique. In January 2013, Lake Michigan dipped below its lowest recorded water level in almost 100 years of record keeping, but it is now back above these record low levels. Dewart Lake is similar to Lake Wawasee in its relatively small watershed size and close proximity in Kosciusko County. It experienced very low water levels in 2012 and has now recently rebounded back to normal springtime lake levels. Other lakes we are studying around Kosciusko County have quickly moved from low water levels to flooding as well. In fact, the Tippecanoe and Barbee lake chains have experienced such high water levels that the DNR recently restricted all motorized watercraft to idle speed until levels come back down. Historically, this bounce back from low to high water levels is common in Wawasee and Syracuse lakes (see figure). Since 1943, there were four other times that water levels got as low as in 2012, and in every case water levels rebounded to the normal lake levels the very next year, usually early the next spring as has happened again this year.
Grace College Field Data:
Our Kosciusko Lakes and Streams center at Grace College has been studying the four inflowing streams to Lake Wawasee since May 2012. All four were flowing when sampling began, but in the summer of 2012 all were dry except one with very low flows. In 2013, early spring has shown large increases in flow such that there was more water coming into Lake Wawasee from streams over a four-day period in April than came into the lake in 240 days of sampling in 2012. Local soils are saturated with water, allowing increased proportions of precipitation to get to stream channels.
Evaporation losses from Lake Wawasee were lessened this past winter with some ice cover. Local groundwater has likely been recharged over the winter and spring months to allow springs in the lake to flow once again now that a higher water table surrounds the lake.
We will continue to study Wawasee and Syracuse lake levels this summer and will quantify sources to and withdrawals from the lake to help us better manage water levels in the future. We will also continue our research on blue-green algae in Wawasee and Syracuse lakes. We are still monitoring the inflowing streams to see what materials they are bringing into the lakes, especially now that they are flowing more again.
We will keep WACF and residents informed of our study results and recommendations as they become available.
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