Notes from “Our Changing Lakes - Low Lake Levels in Northern Wisconsin”

July 28, 2009 at the Waters of Minocqua

This Workshop was Sponsored by: UW-Madison Nelson Institute for Environmental Studies, Wisconsin Initiative on Climate Change Impacts, WDNR, and Wisconsin Association of Lakes.

Tim Asplund the state Limnologist with the WDNR called our attention to the fact that over thousands of years there has been a natural rise and fall of water levels that lakes depend on to build habitat.   However, northern Wisconsin is currently in a drought period.  For the last 6 years northern Wisconsin has had 20% to 30% less rain than normal. 

The interesting point is that although our current drought is moderate, compared to droughts in the 1950’s and 1980’s, our lake levels are much lower than in these previous droughts.  For example, Anvil Lake east of Eagle River, is at its lowest level since the 1930’s.   The disconnect between lake levels and the degree of drought leads Tim Asplund and other speakers to believe there are larger forces at work -  forces related to global climate change, how society uses water (high capacity wells, irrigation) and continued development of our shorelines.   With only 6 years of low precipitation it is still too early to accurately predict future trends.

The complexities of lake level changes make some lakes winners and some lakes losers. 

Our large number of lakes differ greatly in size, shape, depth, nutrient status and type of lake (a closed basin dependent on precipitation and ground water or a lake with an outlet, fed by streams).   Shallow seepage lakes, higher in the landscape are more affected by drought than deeper flow through lakes lower in the landscape.  Susan Knight emphasized important precautions people should take on lakes with low levels where the shore or beach has been increased by dry lake bed:

1. Motor boats should stay farther from shore in deep water to prevent propeller scars on the lake bottom and suspension of bottom sediments.

2. People must resist disturbing the exposed lake bed.  When stressed many aquatic plants flower and release seeds on shore that will allow the plants to re-grow when water returns.  Destruction of plants creates new habitat for exotic plants like Purple Loosestrife and Canada Thistle.

3. Do not clean up woody debris. As water returns this wood is needed to provide a home for macroinvertebrates that form the major food base for fish.  Fish grow 3 times faster when woody debris is present. 

4. Protect wetlands as they dry since they are a major habitat for many animals including fish.

Tom Blake from the Rhinelander DNR drew a clear picture of riparian owner rights in the exposed lake bed.   The Public Trust Doctrine says all land and water below the Ordinary High Water Mark (OHWM) is owned by the state which holds the land in trust for public use.

When lake levels drop, only the riparian owner has legal access to the dry lakebed, which is state property. (See Chapter 30 of the State Statues for OHWM information.)

The riparian owner has the right to remove wood and cut plants in a 30 foot wide section to gain access to the lake.   (If endangered species are present the DNR must be consulted.)   However no motorized tool or vehicle can be used to clear the exposed lake bed.  This includes power mowers, ATVs, tractors, etc.  All plant and debri removal must be done by hand.

Mike Meyer again stated that the northwoods area is a significant loon breeding area.  Our lakes are clear and contain enough fish, to feed a loon family (1500 pounds per year).  The majority of northwoods animals depend on healthy lakes.

The actions of riparian owners and lake users become more important when lakes are stressed by drought.   The large attendance, over 200, again shows that Northwoods people care about lake health.

Excerpts taken from Milwaukee Journal Sentinel Newspaper, June 4, 2009.  Article by Dan Egan
For additional information to www/sonline.com/greatlakes

Dan Anderson has just informed me that the Long Lake AIS treatment will be on May 12th and 13th, weather permitting.

Hi all. Dad and I went down to the dam last night. There is a bit of open water at the South end of the Lake but the rest remains iced over. Not for long, though! The lake is very low - about 1696.6. Last year at this time, it was a good 2 feet higher. And, I note sadly that the dam is open a full 2 inches! I’ve attached a few photos. If you click on the thumbnail, you can see a larger version of the picture.

Best to all,
Tuckey