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Tippecanoe River Freshwater Mussels


NIPSCO, USFWS, Indiana DNR and SFLECC Provide Update on Status of Lake Freeman Lake Levels

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August 6, 2014


Nick Meyer, NIPSCO Director of External Communications


MONTICELLO, Ind. – The lack of sustained rain and dry conditions in the area has resulted in lower-than-normal lake levels at Lake Freeman.  In an attempt to improve the current lake level situation at Lake Freeman, Northern Indiana Public Service Company and the U.S. Fish and Wildlife Service are working together to implement a plan that will reduce the amount of water being released from Lake Freeman while maintaining protection for endangered mussels. Without additional rainfall, depths could continue to be reduced.


NIPSCO will continue to maintain the required minimum flow of 500 cubic feet per second (cfs) in accordance with USFWS, but the monitoring point for that measurement will now be taken from the existing Oakdale USGS gauge, located closer to the dam.  This change is a component of the Abnormal Low Flow (ALF) Plan under development by NIPSCO and the Service to address impacts to endangered mussels in the Tippecanoe River downstream of Oakdale Dam.  Making this change will also provide for better monitoring of the dam's impact on river levels.


The Tippecanoe River supports one of the most significant and diverse freshwater mussel populations in the United States.  Under the Endangered Species Act, it is the responsibility of the USFWS to make sure endangered mussels – even individual ones – are not harmed or killed.  Protecting these mussels protects other aquatic life – fish, for example - and makes the Tippecanoe River a very special place for those who live along it or use it for recreation.  There are many dense mussel assemblages with high diversity (many different species) downstream from Oakdale Dam, including several areas that support state- and federally endangered species.


NIPSCO will be closely monitoring the effects of the immediate implementation of this part of the ALF Plan, but cannot make any prediction on its impact to the lake level.


As of 4 p.m. ET on Wednesday, August 6, 2014, the surface elevation taken near the face of the Oakdale Hydroelectric Dam was measured at 15.2 inches below the normal operating level of 610.35ft. The change in surface elevation measured at the hydro does not reflect or equate to the same potential change in depth for other areas of the lake. Surface elevation is the relative measurement to sea level, local datum. NIPSCO does not measure average depths.  A change of .01 ft in the surface elevation equates to 1/100th of a foot or .12 inches.


Indiana Department of Natural Resources Conservation Officers remind the public to be mindful of their surroundings and be aware of any submerged objects in or underneath the surface of the water.  Due to the water levels, objects such as tree stumps, old dock pilings and such may start to show or become a hazard to boat operators, swimmers, and tubers.


NIPSCO will continue to be in close coordination with the Indiana DNR, SFLECC, Emergency Management, USFWS and other authorities to provide regular updates until levels return to normal.


At this time, Lake Shafer at the Norway Dam continues to measure at normal lake levels.


For current information on lake elevation and flows, visit www.nipscohydro.com.


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Last updated: September 21, 2016