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Wisconsin River Report July 27, 2006

Wisconsin Valley Improvement Company 2301 North Third Street Wausau, WI  54403 For more information contact Sam Morgan Phone: 715.848.2976, ex 301 Email: morgan@wvic.com

 

Recent Thunderstorms Not Enough to Break Drought

 

Recent thunderstorms that dropped 1.5 to 2.5 inches of rain on some areas in northern Wisconsin were not enough to overcome the extreme drought conditions that have gripped the area this summer according to Wisconsin Valley Improvement Company of Wausau. The thunderstorms moved across the area in bands dropping as much as 2.60 inches of rain at the Willow Reservoir near Hazelhurst, but as little as 0.37 inch in Wisconsin Rapids. After rainfall amounts that averaged 68% below normal in April and 51% below normal in June, the late July rain produced virtually no runoff and left river flow and reservoir water levels unaffected.

The flow of the Wisconsin River at Merrill averaged 1,170 cubic feet per second (cfs) for the week, 45% below the July normal of 2, 164 cfs. Water released from WVIC’s northern reservoir system provided 75% of the river flow at Merrill. Without the water released from reservoir storage, the Merrill flow would have been only 290 cfs, a whopping 87% below normal. At Wisconsin Rapids, the weekly average flow of 1,298 cfs was 60% below normal, reflecting the drier conditions in the central basin. Water from the northern reservoir system and the Big Eau Pleine Reservoir provided 79% of the river flow at Wisconsin Rapids. Without reservoir water, the Wisconsin Rapids flow would have averaged 90% below normal. The flows on smaller tributary rivers have dropped to critically low levels. The flow of the Big Eau Pleine River at Stratford dropped as low as 1 cubic foot per second early in the week, compared to the long-term average of 76 cfs in July. The Spirit River near Spirit Falls was not much better, falling to 3 cfs compared to the July long-term average of 47 cfs.

Storage in the Wisconsin River Reservoir System dropped 4% last week to only 55% of capacity. Water levels in the five large man-made reservoirs are dropping rapidly. The Rainbow Reservoir near Lake Tomahawk is 7.5 feet below maximum, the Willow Reservoir near Hazelhurst is 6.8 feet below maximum, the Rice Reservoir north of Tomahawk is 4.0 foot below maximum, the Spirit Reservoir south of Tomahawk is 4.3 foot below maximum, and the Big Eau Pleine Reservoir near Mosinee is 6.7 feet below maximum. Without additional heavy rainfall, reservoir water levels will continue to decline. Water levels in many of the natural-lake reservoirs are also well below normal and falling. For example; Twin Lakes near Phelps is 1.3 feet below the summer target level, Long and Sand Lakes near Phelps are 1.4 feet below the summer target level, and the Minocqua chain of lakes is 0.8 foot below the summer target level. Thus far, no water has been released from the natural-lake reservoirs to augment the flow of the Wisconsin River. The water levels are dropping simply because of the drought conditions.

 

 

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