Record Rains Raise Lake Levels, Slow No Wake Orders Now in Effect for All Yahara Lakes

October 03, 2019
John Reimer, (608) 224-3730
County Executive

Annual Rainfall Totals Now One Foot Above Average

Slow no wake orders are now in effect for Lakes Mendota and Kegonsa, as southern Wisconsin continues to experience significant rains. Previous slow no wake orders were issued last week for Lakes Monona and Waubesa and remain in effect.

Dane County has now received 40 inches of rain in 2019, a foot above the annual normal. Rain totals from Tuesday and Wednesday of this week (3.35 inches) were nearly an inch above the typical October total of 2.4 inches. Additionally, we saw twice as much rain fall in September than the normal, with 6.80 inches falling. The average is 3.13 inches of rain.

This week’s heaviest rains fell in northern Dane County, which is contributing to a rise on Lake Mendota. Lake Mendota has increased about 10 inches in the past week and may come up further as run-off enters the lake.

While lake levels are high, they remain below 2018 peaks. Lake Monona is 10 inches lower today than its peak last summer. Monona is slightly below 100 year levels, while Waubesa eclipsed that figure overnight.

On dry days, given reduced plant growth in the Yahara River in the fall season, the lakes should be able to drop up to a ½ inch per day given current flow rates. It may be October, but Dane County aquatic plant harvesters remain in the Yahara River ensuring maximum flows.

Slow no wake orders are now in effect for Lakes Mendota, Monona, Waubesa, and Kegonsa until further notice.