Frequently Asked Questions & Concerns
Water, Erosion, Temperatures, Trout
Q: Is it unusual to remove dams?
A: No, in fact 50 dams have been removed in Wisconsin since 1990. Visit our "Library" link to get a list of the dams that have been removed, with some before and after photos.
Four dams were recently removed from the Prairie River in Wisconsin. Check out this page from the City of Merrill's website, with lots of pictures. At first, dam removal was controversial in their community; but now that the dams are gone you can see that the City is extremely proud of their beautiful river.
Q: What happens to temperatures downstream if the dams are removed?
A: The two impoundments (Lakes George and Louise) are shallow and slow. They warm up the river water in the summer, and cool the water down in the winter. This means that the lower river has larger temperature extremes than the upper river. The water temps of the Kinni have been extensively studied (20 years of temperature records), and a summary of the data can be downloaded from our "Library" page. Water temperatures in Lakes George and Louise can reach 80° (City data), which is fatal to brown and brook trout. If the dams are removed, then the river temperatures downstream will be less extreme (water not so hot in the summer and not so cold in the winter) — and this is better for trout.
Q: What is the effect of the dams and impoundments on river temperatures?
A: In the summer, 20 years of data show that the average temperature just upstream of the dams (Division Street) is 61° F (~ 16° C) and the temperature just downstream of the lower dam is about 66° F (~ 19° C). So, as the river goes through town and the two impoundments it warms up about 5°.
66°F is considered a "threshold" temperature for trout. Above the dams this temp was exceeded on only 9 days in summer 2012; but below the dams this river temp was hotter than 66°F on 39 days. This is a more accurate indication of the temperature impact of the dams because it is the extreme temps that threaten trout, not the average temps. (For example, 6 hours of 85° water will kill trout, but that sort of short event will barely change the 20-year average temps.) There are 91 days in 'meterological summer,' and on 39 of those days (43%) the temps were higher than the threshold temperature. This is a significant impact, and possible risk. More detailed information about river temperatures is on our Library page.
Q: If the dams are removed will there be more water downstream?
A: No. Every gallon that enters the impoundments must leave the impoundments at the same rate. So, if the dams are removed, the amount of water downstream does not change.
Q: Don't our dams help prevent floods?
A: No. Our two dams are operated so that the impoundments are always full (this is called "instantaneous run of the river"). Since the impoundments are always full, they can't catch and hold water during periods of high runoff. Some really big dams can be operated in a way to prevent or delay floods by drawing down their reservoirs and creating space to capture flood waters. Our dams can't do that.
Q: What about the silt in the impoundments?
A: The City tested the silt in the Lake George impoundment. When we get a copy of the report we will put it on our "Library" page for you to read. We expect there will be more studies done on siltation before dams are considered for removal. We do not know of any silt problems that cannot be solved.
Q: Will there be new erosion?
A: Not if the dams are drained down and recovered properly. There must be engineered plans that we all have a chance to review and comment on. We can avoid erosion problems by doing this right — draining down at the correct time of year, and seeding new grasses when they will sprout quickly to hold the soil. It will take time to prepare a good plan.
Q: Aren't dams good for fishing? I know of some great "tailwater" fisheries.
A: The Kinni dams are not "tailwater" fisheries. Tailwater dams are typically big dams with huge, deep reservoirs. Large tailwater dams catch and store snow-melt and spring-runoff and then release water at other times of the year. In contrast, the Kinni impoundments are extremely shallow. The Kinni dams are way too small to store water for later release; and they do not 'stratify' water the way that tailwater fishery dams do. Water temperatures in Lakes George and Louise can reach 80° (City data), and this is a fatal temperature for brown and brook trout. Trout populations on the Kinni above the dams have been measured at more than 10,000 per mile; below the dams, trout population is less than half this size.
Q: What happens to the geese and swans?
A: The Lake George Recovery Plan adopted by the City includes new wetland areas that should be good waterfowl habitat. We could have a Lake Louise Recovery Plan that also provides wetland areas.
Q: What about our wastewater treatment plant?
A: The City has a DNR permit to discharge treated wastewater to Lake Louise (a "warm water" impoundment). But the standards in the permit, and the standards that our treatment plant already meet, are the DNR's more stringent coldwater standards, not the warmwater standards. The DNR tells us that if the Powell Falls dam is removed, the existing wastewater discharge permit would not need to be amended.
It might be desireable to discharge our treated wastewater to a restored wetland area that is created when the Lake Louise impoundment is recovered, but this is probably optional. Our wastewater treatment plant discharges about 1.2 cubic feet per second of treated water (at about 69°). Because this is a small volume of water compared to the Kinni's average flow, and because the removal of the upper dam will decrease average river temperatures, the DNR has told us that it does not think that discharging directly to the Kinni would be a problem. For more information, please see the DNR memo in our Library.
Money
Q: How much will it cost to have the dams removed?
A: We will need detailed cost estimates before dam removal is considered. Two dams were removed from the Willow River not long ago. The Mounds Dam was removed in 1998 for $170,000 (the pre-removal cost estimate was $1,100,000, so the final cost was 84% less than quoted). The Willow Falls Dam was removed in 1992 for $450,000 (the cost estimate was $622,000, final cost was 27% less than quoted). Both of the Willow dams were much larger than our dams. Willow Falls dam created a 100 acre impoundment, and Mounds dam impounded 57 acres. On the Kinni, our dams each impound a 16 acre lake. Mounds and Willow Falls dams were both more than 58 feet tall. Our dams are about 24 feet tall. For more comparisons, click on the "About Our Dams" link above.
Q: How much electricity do our dams generate for us?
A: The most recent numbers released by the City show that our two dams produce about 1.3% of the electricity we use. RF Utilities buys about 98.7% of its power from WWPI.
Q: Don't the dams provide 'free' power? The Utility Dept says they make a profit.
A: The Utility Dept reports that the dams make an 'operational profit' of around $65,000 a year. But, we don't know yet if they have considered the expensive maintenance and long-term repairs that our dams have had (and will eventually need again). We are doing some research, and will let you know if our dams are making a profit each year, or losing money. We need to know.
Green Power
Q: Isn't hydroelectric power "green"?
A: Hydro dams are more 'gray-green' than pure green. Hydro-generation does have a smaller carbon impact than, say, coal-generation. But our dams catch sediment and silt, and they affect water temperatures downstream. Our impoundments turn green with algae blooms. If the dams are removed, then we should locally generate the power they used to provide. This should not be too difficult. The 1.4% the dams currently supply can probably be saved through energy conservation measures. The River Falls Utility Dept has award-winning conservation efforts and solar-generation projects, and we know they want even more successes. Through conservation, the City reports that 1 million Kwh have been saved each year.