Norway Dam

File photo

To help maintain water flows to irrigate several species of endangered freshwater mussels, NIPSCO uses Lake Freeman.

MONTICELLO — An Abnormal River Conditions watch has been issued for Lake Freeman because average water flows have dropped below predetermined standards.

According to a newsletter issued Wednesday (Sept. 8) morning by the Shafer Freeman Lakes Environmental Conservation Corporation, US Geological Survey gauges in Buffalo and Winamac have dipped below discharge rates of 410 cubic feet per second and 300 cfs, respectively.

On Sept. 3, SFLECC issued an advisory that lake/river conditions were approaching abnormal levels, adding that an ARC event won’t be triggered until and unless readings reached 410 cfs or below at Buffalo or 300 cfs at Winamac.

As of 6:22 a.m. Sept. 7, the 24-hour daily average at the Buffalo USGS gauge was 404 cfs and the 24-hour daily average at the Winamac USGS gauge is 295 cfs.

The surface elevation taken near the face of the Oakdale Hydroelectric Dam was measured at 609.9 feet below the normal operating target of 610.35 feet.

NIPSCO officials said in a press release Wednesday that without additional rainfall, depths could continue to be reduced.

In its Wednesday newsletter, SFLECC said 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. A change of .01 feet in the surface elevation equates to 1/100th of a foot or .12 inches. NIPSCO does not measure average depths.

The flows are regulated due to the discovery of endangered mussels downstream from the Oakdale Dam in the early 2010s. Because of that, water must be released from Lake Freeman and, at times, Lake Shafer to help keep them alive during times of drought or considerable lack of rainfall.

In July 2020, Lake Freeman’s water levels began receding after the area experienced a “moderate drought.” Lake levels dwindled by as much as 12 feet until a series of late autumn rain events and a couple of heavy winter snows this year helped boost lake levels. As of March 1, water levels had returned to normal standards and remained static.

Last week’s newsletter stated NIPSCO will maintain a discharge rate of either 1.39 times the flow of the previous 24-hour daily average flow measured at the USGS Buffalo gauge or 500 cfs through the Oakdale Dam, whichever is less, in accordance with its Federal Energy Regulatory Commission (FERC) license.

In late March, SFLECC, after a six-month wait, received word from the US Court of Appeals in the group’s lawsuit against USFWS and FERC that there is nothing wrong with the USFWS’s use of linear scaling to determine the amount of water flow out of Oakdale Dam during abnormal low flow events. SFLECC had maintained the formula used was inaccurate and used flawed data.

But the court also said FERC and USFWS, failed to determine if USFWS’s requirements were a “minor” change to the operations of the Oakdale Dam.

The matter revolved around opening the dams to provide water to the endangered mussels. It was in response to the 2012 drought, during which USFWS mandated NIPSCO, the owner of the Oakdale and Norway dams, to open Oakdale’s gates and send 500 cubic feet per second of water from Lake Freeman during “low flow events” to water the habitat of endangered mussels.

NIPSCO‘s issued operating license through FERC required the power company to keep the lake levels close to its “run-of-the-river” designation — guidelines that had been in effect for more than 80 years, according to SFLECC. FERC made amendments to the license in 2018.

In response to USFWS’s mandate, SFLECC led a coalition of almost 3,000 lake property owners, businesses and local governments in Carroll and White counties and filed a protest that bounced around the court system for about eight years.

SFLECC’s newsletter warns people to be mindful of their surroundings and 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.

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