New Bagnell Dam Licence Benefits Landowners, Wildlife, Recreation - by: Jim Low

First posted on 05-04-2007

Anglers on both sides of Bagnell Dam can expect better fishing in the future, thanks to new requirements written into the 40-year hydroelectric plant operating license issued to Ameren-UE in March. The Missouri Department of Conservation was instrumental in developing provisions to benefit landowners, fish and wildlife. The new license also will boost the area booming fish- and wildlife-based tourism industry. (Missouri Dept. of Conservation photo)
Conservation officials made sure that natural values received their due in the 40-year license.

LAKE OF THE OZARKS-State conservation officials say a license recently issued to operate the Osage Hydroelectric Project has benefits for fish and wildlife, for citizens trying to protect their land and for the burgeoning nature-based tourism industry on Lake of the Ozarks.

On March 30, The Federal Energy Regulatory Commission issued a license that allows Ameren-UE to continue operating Bagnell Dam on the Osage River in Camden County. The license - the third granted in the hydroelectric plant’s history - is the product of more than a year of negotiations between Ameren-UE, citizens along the lower Osage River and Lake of the Ozarks, the U.S. Fish and Wildlife Service, the National Park Service and the Missouri departments of Conservation and Natural Resources. Missourians will get much more than just electricity from Bagnell Dam for the next 40 years.

Union Electric began acquiring land for Bagnell Dam and 50,000-acre Lake of the Ozarks in 1927. Large reservoirs were rare at the time, and streams were plentiful. Planners gave little thought to how the dam and its electricity generating activities would affect people, land and wildlife downstream. Over the following decades, however, the impacts became clear.

Although the hydroelectric plant provides only a small part of Missouri’s power needs, it plays a key role in meeting peaks in power demand. For example, when air-conditioners are working overtime to cool homes and businesses, Ameren-UE can release water through Bagnell Dam’s turbines, quickly adding electricity to avoid having to buy power from more expensive sources. When demand falls off drastically after sunset, the utility can shut off the flow of water until the next peak in power demand.

This pattern of use causes rapid rises and drops in the river downstream from Bagnell Dam. Besides being inconvenient for hunters, anglers and recreational boaters, the rapid fluctuations contribute to erosion of stream-side agricultural fields. Changes in the water level on Lake of the Ozarks cause problems for thousands of people who have homes, sea walls and fishing and boat docks at the popular recreational destination.

Then there are fish kills. Some fish are sucked into water intakes on the lake side of Bagnell Dam and killed by the violent passage through hydroelectric turbines. Others die in the violent currents created by flood flows through the dam’s spillways.

Fish and wildlife also suffered from poor water quality caused by the hydroelectric plant. Oxygen-poor water drawn from deep below the surface at the dam to turn turbines fill the river and leave aquatic life gasping for breath.

The Conservation Department brought all these concerns to the table when the Osage Hydroelectric Project’s previous, 30-year license neared its February 2006 expiration date, and negotiations for the next license began.

“The people of Missouri have let Ameren-UE use the Osage River to generate electricity for profit for 70 years,” said Conservation Department Assistant Director Denise Brown. “In return for that very valuable privilege, we asked for reasonable accommodations between the needs of wildlife and power generation. We succeeded to a large degree.”

Brown said some of the accommodations will be made immediately. Others will take several years to develop and implement. The end result will be a better balance of benefits to Missourians, from electricity to recreation and protection of private property.

One major accommodation will be increased dissolved-oxygen levels in the river below Bagnell Dam. Ameren-UE will replace two of its existing hydroelectric turbines with more efficient ones that mix more air with water flowing out of the turbines. This will hasten the return of more healthy conditions for fish and other aquatic wildlife after power-generation runs.

Ameren-UE also agreed to double the amount of water it releases to maintain flows in the lower Osage River when it is not generating electricity. While the new minimum flow of 900 cubic feet per second still is small compared to the river’s natural flow, it will make a significant difference in the amount and quality of aquatic habitat available to fish and the plants and animals - such as crayfish and insects - that fish rely on for food. Increased minimum flows also will ensure better spawning habitat and make boating more practical in the river downstream from Bagnell Dam.

Under the terms of the new license that the Conservation Department helped develop, Ameren-UE is required to develop new measures to prevent fish kills. One is placing a net in front of turbine intakes on the lake side of the dam to keep fish out.

The new license also restricts the way and the rate at which Ameren-UE can release water from Bagnell Dam to maintain a stable lake level following heavy rains. In the past, water has been released rapidly and through only a few flood gates. The water was moving so fast that it killed fish below the dam, sometimes ripping the heads off large paddlefish during their spring spawning runs. Under the new license, releases will be spread out over a longer time and will have to be channeled through more gates to reduce the violence of the flows.

In the past, rapid changes in the amount of water released after flood events have contributed to erosion by creating unnaturally rapid drops in water level downstream. Earthen banks that became saturated with water during high flows collapsed when the water receded rapidly, because of the weight of the water inside them. The new license requires Ameren-UE to change flows more gradually, allowing water to seep out of stream banks as the water recedes. Again, river boaters will benefit from less drastic water level fluctuations.

Ameren-UE accepts responsibility under the new license for improving habitat for freshwater mussels and other plants and animals that are part of a healthy stream ecosystem. The company also will take responsibility for stocking to replenish fisheries in Lake of the Ozarks and below the dam. The utility will increase water-quality monitoring and expand its analysis of erosion problems in the lower river to find ways to further reduce the impact of its operations.

“The requirement to manage lake levels similar to the past few years will result in better spawning conditions for fish,” said Fisheries Programs Coordinator Bill Turner, who helped negotiate terms of the license. “It also will keep the lake level more stable. This is a really big win for tourism on Lake of the Ozarks.”

-Jim Low