Impacts of the recent prolonged rain event

Based on the flooding of 2018, there is always a lot of community concern when we have a prolonged rainfall event. Although all of the lakes will continue to gradually rise above summer maximums as the water works its way through the watershed, it will not rise to flood levels or anywhere near where we were in 2018.

The rainfall for the rest of the week will be minimal. Dams in the lower watershed will be open while water will be restricted out of the Tenney Dam and held back in Lake Mendota to not overwhelm the lower lakes.

We have our quarterly Lake Levels update on Thursday and we will get a detailed report from staff and I will post about it.

Here is a link to our Lake Levels page:
https://lwrd.countyofdane.com/lake-levels

Here is a link to operational dam changes that I had the department add to the web site in the last term:
https://lwrd.countyofdane.com/Dam/TabularData

Here is a detailed summary that was put out to the public from the Land and Water Department:

"From the recent rainfall, all lakes are above summer maximum. The past weekend rainfall totaled lower amounts of approximately 3" in the northern watershed (Mendota) compared to 5" in the southern (Kegonsa). Currently all the downstream dams (Babcock and Lafollette) are wide open. We are seeing aquatic plant growth in the river starting to die off for the season which reduces friction and increases flow. Near the end of the week, the lower lakes are expected to experience peak water levels from this weekend's rain.

We will continue to keep Babcock and Lafollette dams wide open with lower flows out of Tenney to reduce lake levels from Monona to Kegonsa (due to experiencing higher rainfall amounts). It is anticipated near the end of the week (after peak levels on the lower lakes) Tenney dam will be opened to reduce Lake Mendota levels. From today to near the end of the week, all lakes are expected to rise but not to flood levels.

The National Weather Service is predicting less than a quarter of an inch for the remainder of the week. We will continue to monitor rainfall predictions and runoff into the lakes and make adjustments as weather forecasts or flows change."