Oakdale Hydro Generating Station Oil Spill
At approximately 6:40 a.m. CT on Monday, Dec. 9, 2024, NIPSCO personnel at the Oakdale Hydro in Monticello, Indiana, became aware of an equipment issue and subsequent hydraulic oil leak of under 50 gallons into the Tippecanoe River.
NIPSCO supervisors and crews continue to work with local emergency responders and the Indiana Department of Natural Resources (DNR) in Carroll and White counties to contain the oil. Booms designed to capture the flow of the oil have been deployed across the Tippecanoe River at Camp Tecumseh, the intersection of Highway 18, and at the point where the Tippecanoe joins the Wabash River. These booms are performing as intended, absorbing the oil and serving as a preventative measure from further travel downstream.
NIPSCO is working closely with the Indiana Department of Natural Resources (DNR), along with the Indiana Department of Environmental Management (IDEM) and the Environmental Protection Agency (EPA) on clean-up and remediation efforts. Residents in the area may observe continued aerial and water-based survey work related to these efforts. We appreciate the community’s cooperation and patience as we work as safely and quickly as possible on clean-up efforts.
Current Lake Levels
Norway Hydro Plant
Lake Shafer
Oakdale Hydro Plant
Lake Freeman
Understanding plant lake levels*
The Lake Levels (Elevation in feet Local Datum) represent the level of the lakes at the hydros.
Norway/Lake Shafer FERC operating target
- Normal: 645.15 ft
- Low-High: 644.90 ft - 645.90
Oakdale/Lake Freeman FERC operating target
- Normal: 610.35 ft
- Low-High: 610.10 ft - 611.10
Understanding plant discharge levels
The Plant Discharge (cubic feet per second) represents the water flow through each plant.
- Flood Emergency: as conditions warrant
- Flood Warning: 13,000 Cubic Feet/Second
- Flood Watch: 9,000 Cubic Feet/Second
- ALF: <=315 Cubic Feet/Second**
* Change in elevation taken near the face of the hydros does not reflect or equate to the same potential change in depth for other areas of the lake. A change of .01 ft in the surface elevation equates to 1/100th of a foot or .12 inches. NIPSCO does not measure average depths.
** An Abnormal Low Flow (ALF) event occurs at the Oakdale Dam when the previous day’s 24-hour average flow at the Buffalo USGS gauge is equal to or less than 260 cfs. During an ALF event, NIPSCO is required to maintain at the Oakdale USGS gauge the lesser of, a) 1.39 times the previous day’s 24-hour average flow measured at the Buffalo USGS gauge or, b) 315 cfs. This is required by the Operations and Compliance Plan approved by the FERC Order issued March 30, 2023. Lower lake levels could result. An ALF event ends once the 24-hour average rises above 260 cfs at the Buffalo USGS gauge and hourly readings at the Oakdale USGS gauge are above 315 cfs. (This is based on USGS data.)Sign up for alerts
Whether or not you are a White County resident, the White County Emergency Alert Program allows anyone to sign up for alerts about emergencies and other important community news including hydro updates.
Contact information
For information on conditions along the Tippecanoe River, please call your County Emergency Management Agency.
- Carroll County Emergency Management Agency: 1-765-564-4243
- Tippecanoe County Emergency Management Agency: 1-765-742-1334
- White County Emergency Management Agency: 1-574-583-4692
For more information
- Norway USGS Gauge
- Oakdale USGS Gauge
- Delphi USGS Gauge (Tippecanoe River and SR 18)
- Winamac USGS Gauge
- Buffalo USGS Gauge
Frequently asked questions
Why does the lake level of Lake Freeman change during a drought, but Lake Shafer is unaffected?
NIPSCO’s current FERC operating license requires a specific discharge based on river flows. These discharge rates must pass through the Oakdale Dam to protect the endangered species of mussels living downstream of the dam. At the same time, the FERC license also requires maintaining the lake level of Lake Shafer with no deviation. In a drought condition, the discharges must come from Lake Freeman until normal flows resume.
Thank you for your response.
What are the flooding emergency classifications for the dams?
Classifications for a flooding emergency are as follows:
Flood Watch
One or both dams discharge of 9,000 cubic feet per second
Flood Warning
One or both dams discharge of 13,000 cubic feet per second
Flood Emergency
As conditions warrant
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Do the dams create flooding upstream?
The Norway and Oakdale dams cannot hold water back. The lake levels are monitored at the face of the dam and adjusted as needed to maintain the level within the required FERC license elevations.
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Why is there flooding downstream with dams in place?
Both the Norway and Oakdale dams are designed and operated as "Run of the River" facilities. This means that the water that flows down the river must pass through the each dam and continue downstream. The dams cannot hold back water and are not designed to be flood control dams.
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Does someone work at the Norway and Oakdale dams 24 hours a day?
The Norway and Oakdale dams are staffed around the clock every day of the year. The operators are constantly monitoring lake levels, incoming river flows, and generator operation if electricity is being generated.
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Why is water always flowing through the gates at the Oakdale dam, and not Norway dam?
Water is discharged through both hydroelectric plants to maintain the lake level. The amount discharged will vary between the two plants. This water may flow through the generators or through the floodgates. At the Oakdale plant, a requirement in NIPSCO’s FERC operating license is to have a specific discharge based on river flows. This is due to an endangered species of mussel that inhabits areas downstream of the Oakdale dam.
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What is the amount of electricity generated by the two hydro plants?
The voltage produced by the generators is 2,400 volts. This voltage is then sent through transformers and is stepped up to 69,000 volts to match the transmission lines.
The maximum overall output of the plants is as follows:
Norway: 7.2 MW
Oakdale: 9.2 MW
Total of both plants: 16.4 MW
Total generation from both hydroelectric plants represents less than 1% of the total electricity produced by NIPSCO.
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How do I know if Lake Freeman levels might be affected by a drought?
Whether or not you are a White County resident, the White County Emergency Alert Program allows anyone to sign up for alerts about emergencies and other important community news including hydro updates. You can sign up using this link below.
Click here to sign up for emergency and hydro condition alerts.Thank you for your response.
How do hydroelectric dams work?
Norway and Oakdale hydroelectric plants were designed and built in the early 1920’s as “Run of the River” dams. In other words, water flowing through the dams downstream is matched as close as possible to the water flow coming into the dams from upstream. There are two main factors needed to control a "Run of the River" dam.
They are to maintain a constant forebay level (lake level) upstream and to have a consistent discharge through the tailrace (downstream). When upstream flows are large enough to turn the generators efficiently, then electricity is produced from the generators.
Licensed by FERC (Federal Energy Regulatory Commission) in 2007 as “Run of the River” facilities, the operating license requires the forebay level (lake level) to be maintained within a 2.4" inch range at Norway and a 3.5" inch range at Oakdale.
The dams represent less than 1% of the total electricity produced by NIPSCO.
Thank you for your response.
How do I find out about conditions on the Tippecanoe River?
For information on conditions along the Tippecanoe River, please call your County Emergency Management Agency.
Carroll County Emergency Management Agency:
1-765-564-4243
Tippecanoe County Emergency Management Agency:
1-765-742-1334
White County Emergency Management Agency:
1-574-583-4692
Thank you for your response.
Are the electric generators always producing electricity?
The generators produce electricity when the river flows are sufficient to operate them. It requires a minimum flow of 400 cubic feet per second to turn the generators. When the flows coming down the river are less than the minimum, the generators are brought offline. The water then passes through the flood gate system.
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Do the Norway and Oakdale plants only generate electricity for Monticello?
Both of the hydroelectric plants generate electricity that is offered into the MISO energy markets. There are no direct circuits from either plants to any specific communities.
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Why are the hydroelectric plants considered “Run of the River dams” and not flood control dams?
These facilities were not built as flood control dams. Norway and Oakdale hydroelectric plants were licensed by FERC (Federal Energy Regulatory Commission) on October 2, 2007. NIPSCO operates these facilities as "Run of the River dams".
The water discharge through "Run of the River" dams is as close to the flow of the river as possible without losing efficiency on the generators producing electricity. There are two main ingredients needed to control a "Run of the River" dam:
- Present discharge
- Forebay level (lake level).
By continually monitoring the lake levels, the operator can approximate the flow of the river. Using the calculated flow of the river, the operator decides needed water discharge to raise or lower the lake level. The lake level at Norway is controlled within a 2.4" inch range, and the Oakdale lake level is controlled within a 3.5" inch range.
At a flood control dam, the reservoir (lake level) is raised and lowered through the year to adapt to different weather conditions. Usually this means very large fluctuations in surface levels. This is accomplished because flood control reservoirs are usually very deep and expansive, and the dam structure is much taller. Neither Lake Shaffer, nor Lake Freeman are very deep, averaging 12 and 15 feet respectively. The Norway and Oakdale dams were not constructed in a way to allow access water to be held upstream.
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Historic timeline of our hydroelectric dams
Currently, the dams are operated with a low flow provision from FERC (Federal Energy Regulatory Commission), and USFW (United States Fish & Wildlife), for discharges through the Oakdale dam. Norway and Oakdale were licensed by FERC on October 2, 2007.
1923
Construction of Norway facility completed and in service.
1925
Construction of Oakdale facility completed and in service.
1933
NIPSCO leases Norway and Oakdale dams.
1944
NIPSCO purchases Norway and Oakdale dams.
2000
Federal Energy Regulatory Commission (FERC) asserts federal jurisdiction, and NIPSCO begins FERC licensing process.
2004
NIPSCO files FERC licensing application.
2007
In October, FERC issues license order, which NIPSCO accepts in November.
FERC order issues original 30 year license with 20 articles.
2014
USFW (United States Fish and Wildlife) issues Technical Assistance Letter mandating discharge from Oakdale Dam due to the Endangered Species Act.
2018
FERC License is modified to include the Technical Assistance Letter.
2023
FERC issues order on March 30, 2023 amending Article 403 and the Project Operation and Compliance Plan. The amendment lowers the flow rates that trigger the lower range of the abnormal river conditions and associated discharge from Oakdale dam.
Disclaimer
NIPSCO is providing information via this website in accordance with FERC requirements and as a public service to agencies and individuals located in Carroll, Tippecanoe, and White Counties, Indiana. The data provided herein is applicable only to the Tippecanoe River in Carroll, Tippecanoe and White Counties, Indiana. To the best of NIPSCO’s knowledge, all information provided on this website is accurate at the time of posting. NIPSCO undertakes reasonable efforts to ensure that all information is accurately updated in a timely manner. NIPSCO makes no representations, guarantees, or warranties as to the accuracy, completeness, currency, timeliness or suitability for a particular purpose of the information provided on this website. The user relies on the data provided herein at user's sole risk. The user should not rely exclusively on the data provided on this website and should take all steps reasonably necessary to verify any information provided herein. NIPSCO specifically disclaims any and all liability for any claims or damages that may result from providing the website or the information contained therein.