A Long- term Lake- Level Monitoring Network for Wisconsin
Lake water-level fluctuations are important to lake and water managers, lakeshore property
owners, developers, and lake users. Lake levels change from year to year, and extreme high
or low levels can present problems by restricting access to water and hampering navigation,
flooding lakeshore property and damaging shorelines and structures, and changing near-shore
vegetation. To respond appropriately, we need to understand why and how lake levels are
changing. Change can occur at various scales of time and space. Weather cycles or climate
change occur over large areas and longer periods of time, which can be summarized at a state
or regional level but vary according to geology, topography, type of water body, and human
use (Wisconsin Academy of Sciences, 2003).
Lakes in Wisconsin may be classified into three general hydrologic/topographic categories:
groundwater flow-through lakes, surface-water drainage lakes, and surface-water flow-
through lakes (House, 1985; Novitzki and Devaul, 1978)). Groundwater flow-through lakes
(also called Seepage Lakes; WDNR, 2001) have no perennial inlets or outlets, and sources of
water are primarily groundwater and direct precipitation. Surface-water drainage lakes (also
called groundwater discharge or ‘Spring Lakes; WDNR, 2001) have a perennial outlet and
small or no inflow streams, and sources of water are also primarily groundwater and direct
precipitation. Because they have an outlet, lake level fluctuations are not as large as those of
seepage lakes. Surface-water flow-through lakes (also termed ‘Drainage Lakes; WDNR,
2001) have perennial inflow and outflow streams, where the source of water is primarily
from surface inflow but groundwater inflow and precipitation may also contribute some to
There is no consistent long-term lake-level monitoring network in Wisconsin to evaluate
climatic effects. Seepage lakes exhibit large fluctuations in stage because water-level
extremes are caused by the cumulative effect of climatic factors over years or tens of years.
These factors make seepage lakes ideal for lake water level monitoring. On the other hand,
water levels in spring lakes and drainage lakes are highly influence by the elevation of the
particular outlet stream. The need for a coordinated lake-level monitoring network was
recognized by the Wisconsin Academy of Sciences (2003, p. 55).
• Establish a long-term lake-level monitoring network to evaluate trends in various regions
of the state. Emphasis will be on relatively natural seepage lakes, which are most
responsive and can give indications of regional changes in climate and hydrology.
• Establish baseline conditions for environmental studies and comparison with short-term
• Provide information to increase the understanding of different lake hydrologic systems
and how they affect lake water levels.
• Provide a framework and protocols for facilitating lake water level monitoring by citizen
volunteers through the Citizen Lake Monitoring Network (CLMN) program.
Establish a long-term monitoring network of selected index seepage lakes located in major
regions of the Wisconsin that reflect climate variations and provide indications of climatic
change. Data from other lakes that may be experiencing unusually high or low water levels
may be compared with data from these index lakes to discern if high or low water levels are
caused by natural or by human activity in the vicinity of the lake.
A core of approximately 10 lakes will be chosen from a list of seepage lakes relatively
unaffected by human manipulation (table 1). Many of these lakes are proposed because they
were monitored in the past and have relatively long periods of record. Additional secondary
criteria, such as a previous hydrologic study, water quality data, and active volunteer
involvement, among other criteria, may be considered during the USGS and WDNR joint
selection process in early 2010. Several drainage lakes (Winnebago, Mendota, Monona,
Koshkonong, table 2) are currently being monitored and have long records of continuous data
that can supplement this core of long-term index lakes. Other lakes may be added to or
supplement this long-term monitoring network after its establishment such as: lakes that are
targeted for monitoring in areas of intensive groundwater development (e.g. Middle
Genesee), in other problem or special interest areas (e.g. Shell Lake, Devil’s Lake), or
shorter-term monitoring needed by lake districts and associations for management purposes.
Moreover, it is hoped that this long-term lake-level monitoring network will provide a
framework and protocols for guiding the CLMN program in monitoring water levels in
additional lakes throughout the state.
All lake monitoring sites that are part of this long-term monitoring network will be
referenced to a surveyed datum twice each year by USGS staff. Water levels for these lakes
will be read during open water by a local observer at about a weekly interval. USGS
personnel will measure stages 2-4 times annually on an opportunistic basis when they are
working near the vicinity of the lake. All lake level observations will be uploaded to the
USGS website for public access. In addition, a method will be developed to link this
information between the USGS and DNR websites. As a future option, a subset of the lakes
could be monitored with continuous recorders and the real-time data presented on the USGS
web site to provide access to current conditions.
The long-term network will also provide the following benefits to any citizen lake water level
• Establish a set of consistently monitored and quality controlled lake water levels,
for which the data will be archived and served to the public on the USGS website
where other relevant water data are available to the public for comparison.
• Serve as an index to evaluate data gaps and possible datum conflicts, and identify
abnormal or unanticipated water level fluctuations in adjacent lakes with limited
• Provide a dataset for evaluating causes of changes and trends in a region and
provide context for evaluating and understanding local perturbations or trends in
• Establish protocols that can be mirrored by the CLMN program for use with
additional lakes throughout the state.
An important part of the USGS mission is to provide scientific information to manage the
water resources of the Nation. To effectively assess the Nation's surface-water and
groundwater resources, the USGS operates streamgaging stations, monitors lakes and
reservoirs, and water levels in wells, using standardized methods. Data from these stations
are maintained in a national data base. Surface-water data are needed to develop information
about flow and stage that can be used by a variety of individuals and agencies for the
planning and management of diverse water-resources projects and programs including flood
warning; flood assessment; lake and reservoir operations; evaluating the effects of changing
land use; and detecting long-term changes in climate. The data are critical to local, state, and
regional water managers for broad-based planning and managing of water-resources projects.
The monitoring stations operated in this State are an integral part of the nationwide surface-
water and groundwater data program. This project addresses the following USGS science
themes and strategic directions: Understanding Ecosystems and Predicting Ecosystem
Change; Climate Variability and Change.
Funding levels listed below are based on a network of 10 index seepage lakes. Additional
lakes could be added or removed from the network using a similar per-lake funding rate.
Total cost of the basic network (assumes 10 lakes):
Installation (recon trip, supplies, surveying, install staff gage)-- $18,600 (first year only)
Operation (surveying, install/adjust staffs, data processing) -- $16,300 annually (+ inflation)
Cost breakdown: WDNR Year 1: $9,300; Year 2: $8,150; Thereafter: $8,150 + inflation
USGS Year 1: $9,300; Year 2: $8,150; Thereafter: $8,150 + inflation
House, L. B., 1985, Stage Fluctuations of Wisconsin Lakes: U. S. Geological Survey and
Wisconsin Geological and Natural History Survey, Information Circular 49, 84 p.
Novitzki, R. P. and Devaul, R. W., 1978, Wisconsin Lake Levels—Their Ups and Downs:
U. S. Geological Survey and Wisconsin Geological and Natural History Survey, unnumbered
report, 11 p.
Wisconsin Academy of Sciences, 2003, Waters of Wisconsin: The Future of Our Aquatic
Ecosystems and Resources: Wisconsin Academy of Sciences, Arts and Letters, Madison,
Wis., 179 p.
Wisconsin Department of Natural Resources, 2001, Wisconsin Lakes: Wisconsin Department
of Natural Resources, Pub-FH-800, 180 p.
Table 1. Seepage and Spring lakes in Wisconsin with considerable historical stage data to be
considered for inclusion in the lake water-level monitoring network.
Lake Name County Lake Type Periods of stage records
Anvil Lake Vilas Seepage 1936 - 92, 1998 – present
Bear Lake Portage Seepage 1965, 1970, 1974, 1978, 1979
Beaver Lake (called Waukesha Spring/ 1926 – 73
Spring Lake in WI lake Seepage
book and has
Boot Lake Oconto Seepage 1935 - 65, 1976 – 80
Cedar Lake (has well Manitowoc Seepage 1936 – 1983
De Neveu Fond du Lac Seepage 1936 – 64
Devils Lake Sauk Seepage 1922 – present
Emily Lake Portage Seepage 1977-79
Fish Lake Dane Seepage 1966 - 81, 1985 – 2005
Fish Lake Waushara nr Seepage 1971 -72, 1978 – 79
Irogami Lake Waushara Seepage / 1966 - 77, 1979
nr Wautoma Spring
Little Green Lake Green Lake Seepage 1936 - 64, 1979, 1991 - 2003
Long Lake Bayfield Seepage 1964 – 81
Long Lake Waushara Seepage 1977 – 79
Morgan Lake Florence Seepage 1971 - 79, 1986 – 98
North Lake Walworth Seepage 1937 – 81
Pickeral Lake Portage Seepage 1977 – 79
Pine Lake Chippewa Seepage 1936 - 65, 1974 - 79
Pine Lake (has Waukesha Seepage / 1931 – 79
intermittent inlet & Drainage
outlet) (from Beaver
Silver Lake Columbia Seepage / 1936 - 65, 1975 - 79
(intermittent outlet?) Spring
Shell Lake (3 billion Washburn Seepage 1936 - 81, 1983 – present by city
gallon diversion in
Wheeler Lake Oconto Seepage 1936 - 81, 1985 – 91
Table 2 Drainage lakes in Wisconsin with considerable historical stage data to be considered
as secondary lakes in the lake water-level network.
Lake Name County Lake Type Periods of stage records
Amnicon Lake Douglas Drainage 1936 - 64, 1970 – 78
Big Lake Vilas Drainage 1937 - 45
Bone Lake Polk Drainage 1935 – 67, 1974 - 80, 1984 - 90
Browns Lake Racine Drained 1936 - 64
Connors Lake Sawyer Drainage 1936 - 65, 1976 - 79
Eagle Lake Racine Drainage 1936 - 64, 1975 - 79
Koshkonong Jefferson Drainage 1987 - present
McKenzie Lake Burnett Drainage 1936 – 78, 1984 - 91, 1997 - 98
Mendota Lake Dane Drainage 1916 - present
Monona Lake Dane Drainage 1915 - present
Rib Lake Taylor Drainage 1936 - 79
Lake Ripley Jefferson Drainage 1936 - 61, 1975 – 79
Turtle Lake Walworth Drained 1936 - 65, 1975 - 79
Winnebago Fond du Lac Drainage 1882 - present
Yellow Lake Burnett Drainage 1941- 64