The Endangered Species Act prohibits take – killing or harming – federally threatened or endangered species unless a permit is granted and steps are taken to avoid and minimize take. There are five federally endangered species in the portion of the Tippecanoe River below Oakdale Dam. They include the clubshell, fanshell, rayed been, sheepnose and snuffbox. The rabbitsfoot, a candidate for federal listing is also found here, along with several state-listed mussel species.

Pruitt said the Service is working with NIPSCO and the Indiana Department of Natural Resources to respond to the low water events that have twice exposed large numbers of mussels in the Tippecanoe River in the past two weeks, killing some endangered mussels. Based on the best available information, a minimum release of 200 cubic feet per second of water from Oakdale Dam into the Tippecanoe River is needed to prevent additional mortality of endangered mussels. NIPSCO is maintaining that minimal release while exploring other options, including pursuing a permit for incidental take of endangered mussels.

“NIPSCO is the expert on manipulating the water levels in the two impoundments on the Tippecanoe River,” said Pruitt. “The Service’s role here is not to direct how water management is done, but to ensure that the minimum flow enters the Tippecanoe River below Oakdale Dam. We’re fortunate that at this point, water levels at the lakes have not fallen below normal operating stages.”

Pruitt said mussels are sometimes stranded during normal summertime conditions, but this year’s exposures of mussel beds in the Tippecanoe River are unprecedented. Mussel populations are slow to recover from such events, which are especially detrimental to endangered species, whose numbers are already critically low.

Water levels in the lower Tippecanoe River are at historic lows. The flow is almost 200 cfs below the previously measured low, which occurred during the drought of 1988, and is more than 1,000 cfs below average for this time of year.

Around the state, the drought is having significant impacts on agricultural crops, waterways and impoundments. According to data from the National Weather Service (http://water.weather.gov/), water levels at Morse Reservoir near Indianapolis dropped almost 2 feet between July 1 and July 12. In southern Indiana, Patoka Reservoir is more than 3 feet below normal summer pool level.

Freshwater mussels are among the country’s most imperiled species and play a key role in maintaining healthy ecosystems.  The presence of diverse and reproducing populations of mussels indicates a healthy aquatic system which means good fishing, good water quality for waterfowl and other wildlife species, as well as insurance that our water is safe. When mussel populations are at risk, it indicates problems for other fish and wildlife species, and people too.

Mussels perform important ecological functions. They are natural filters, and by feeding on algae, plankton, and silts, they help purify the aquatic system. Mussels are also an important food source for many species of wildlife including otters, raccoon, muskrat, herons, egrets, and some fish.

For more information on endangered species and freshwater mussels, visit www.fws.gov/midwest/endangered.

Information provided by NIPSCO

UPDATED: 7.12.12

Fact Sheet

Record Low Rainfalls & Droughts Present Risk to Endangered Species

NIPSCO Working with Federal, State and Local Stakeholders to Identify Solutions

What is the issue?
NIPSCO, which operates the Norway and Oakdale hydroelectric dams in White and Carroll counties, was directed by the U.S. Fish and Wildlife Service on July 6 to maintain current water flows of 200 cubic feet per second (cfs) through its Oakdale hydroelectric dam to protect a variety of federal and state endangered mussels – including the fanshell mussel – residing along the river bed south of the dam.

This action, depending on evaporation and future rain fall, may result in the potential lowering of the lake level on Lake Freeman and Lake Shafer.

 How will NIPSCO maintain 200 cfs?
While NIPSCO does not want to harm any endangered species or the local environment, the company remains concerned about the potential impact of maintaining the mandated river flows to public safety, boaters, recreation and the local economy should drought conditions continue and lake levels fall further.

NIPSCO is working in collaboration with key community stakeholders and officials to meet the federal mandate with the least amount of impact to residents and businesses.

NIPSCO will utilize Lake Freeman to maintain the required 200 cfs.

What if we get rain? What if we don’t?
A small amount of rainfall will only reduce the impact on the mussels and lake levels temporarily. Without additional rainfall, and if surface elevations for Lake Freeman drop 2ft below normal operating levels, NIPSCO will reassess the impacts.

What about Lake Shafer?
Lake Shafer will only be used to meet the mandated levels as a last resort, and it will continue to operate under FERC guidelines.

How quickly will lake levels change?
Recent rainfalls have helped the situation. However, NIPSCO is unable to predict how quickly levels will change, given the amount of unknown variables that exist.

HELPFUL CONTACTS:

Endangered Species Protection Lake Freeman/Shafer Elevation Levels & Updates
(866) 261-9986, Select Option 1
U.S. Fish and Wildlife Service
www.nipscohydro.com
(812) 334-4261