Water flow expert weighs in on dam

Hydrologist Dr. Paul Richards of the State University of New York in Brockport, N.Y., offered his opinion concerning an emerging controversy regarding whether the Fordam Dam in the Rock River in downtown Rockford has the capacity to maintain recreational river levels north of the dam.

Richards studies surface and ground water flows, primarily in lakes and rivers.

He said, depending on how applicable laws define a run-of-the-river dam, it may be possible for dams such as Fordam to maintain a water level for recreational purposes even in the cases of drought or upstream dams that limit water flow into the “reservoir” that feeds into the dam.

However, Richards cautioned that because variables such as the volume of the reservoir north of the dam, total water flow from tributaries into the reservoir, and time period used to define a run-of-the-river dam are not known, it was not possible to issue a definitive claim of whether the dam is able to maintain a river level boat enthusiasts want for recreation.

Richards said a run-of-the-river dam is usually defined as the water flowing into the dam equals the water flowing from the dam during a calendar year. This means if the river level is low, Richards said it is theoretically possible for the garage door like gates on the dam to be closed during periods of low water flow to increase the river level for recreation, as long as the water is eventually released during non-boating seasons within the year.

However, Paul Callighan, regional external affairs manager for Commonwealth Edison Co., which owns and operates the Fordam Dam, argued that although the dam can control water flow, the dam is not designed for “absolute” control of water flow. He also said he had “no information” concerning the volume of the reservoir, and time period used in defining a run-of-the-river dam.

Boat enthusiasts such Loves Park resident and river barge owner Steve Lucas want ComEd officials to maintain a river level of 702.94 feet above sea level north of the dam, as required when the state issued a permit to operate the dam in 1975. Lucas said that level hasn’t been achieved since May.

“We cannot just totally shut off the flow of water,” Callighan said. He later clarified that statement by saying the gates on the dam are supposed to remain closed until the 702.5 feet level is achieved.

Richards said: “It’s definitely possible there’s not enough water to build up the reservoir. But if the gates are open, I would question why they have them open, and be suspicious of any claims that they can’t maintain that level. …At some point, they will have to open the gates to comply with the law to still be operated as a run-of-the-river dam. They could say, ‘We closed them as much as possible,’ but they do have to release it.

“They can mechanically maintain, increase and decrease the water level. If the volume of water flowing into the reservoir is so little, it might not be possible to maintain the river level. It’s possible that might be true, but I would have to learn more about the volume of water flowing into the dam,” Richards said.

Callighan said he did not have that information and referred that question, and what the time period is for a run-of-the-river dam, to the Illinois Department of Natural Resources (DNR).

Paul Mauer, acting division manager for the DNR’s Water Resources Management section was on vacation, and unavailable for comment. Mauer is familiar with operations of the Fordam Dam.

Callighan said two water-level sensors located in the middle of the dam and on the adjacent east bank regulate the gates, which open and close automatically on site. However, the dam is remotely monitored 24 hours a day at ComEd’s dispatch station in Joliet.

If river levels drop below 702 feet or rise above 703.6 feet, the dispatch center notifies personnel to investigate the situation and take appropriate action.

Lucas wants ComEd to open and close the gates on the dam to maintain a river level of 702.94 feet above sea level on the north side of the dam. He added that river level is what was required when the predecessor to the DNR issued a permit to operate the dam in 1975.

Two weeks ago, Callighan blamed the low river levels on the drought and possible restrictions of water flow into the Rock River somewhere in Wisconsin. He said Aug. 1 the dam did not have “absolute” control of the water flow of the river.

Lucas wants Winnebago County Sheriff Richard Meyers to force ComEd to live up to terms described in the 1975 Illinois Department of Natural Resources (DNR) permit, since Meyers’ department is already voluntarily enforcing an enlarged No Wake Zone on the river for the DNR.

Meyers said enforcement of the river level is not a function of his department.

From the Aug. 3-9, 2005, issue

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