Located in the Lyman F. Anderson Agriculture and Conservation Center 5201 Fen Oak Drive Room 234 Madison, WI 53718-8827 Map to Fen Oak 608-224-3730 email@example.com
Aquatic weeds are harvested by the Dane
County Public Works Department. The county's basic policy
is to cut or harvest aquatic weeds whenever it will enhance
the overall recreational or aesthetic value of the lakes.
The priority as to where cutting occurs depends on the timing
of weed growth and where the cutting will do the most good.
Weeds in the Vilas and Tenney park lagoons are usually cut
first. Cutting is done next on Lakes Monona or Waubesa,
whichever has more weeds. Lakes Monona or Waubesa, whichever
has more weeds. Lakes Mendota and Kegonsa are usually cut
last, and there have been years when weeds have not been
harvested on either lake.
When weeds are cut along the shoreline,
boat landings and swimming beaches receive special attention.
When weeds are particularly heavy, paths are cut along the
residential shoreline and out to the lake. The channel between
Lakes Monona and Waubesa is cut to allow for boat passage.
The river from Lake Waubesa to Lake Kegonsa is also cut
to maintain flow. If weeds are not cut in the river, it
is not possible to discharge the volume of water needed
to keep the lakes from exceeding summer maximum lake levels.
Special events, such as the water ski show
in Monona Bay, the Milk Carton Regatta at Vilas Park, the
triathlon at Warner Bay, and the Badger Sports Festival,
receive priority for weed cutting.
Large weed beds in Turville Bay, University
Bay, Warner Bay, etc., are not cut. If time and money would
permit, paths could be cut through these weed beds for fishing.
Vilas and Tenney parks are cut once again in the fall so
that weeds will not freeze in the ice.
It is illegal for individuals to chemically
treat shoreline areas without a permit from the Department
of Natural Resources (DNR). Health hazards may occur to
people and wildlife when chemicals are applied carelessly.
(Simply because a chemical can be sold does not mean it
is harmless.) Thus, non-chemical methods to control plants
should be explored first by contacting the aquatic plant
specialists in the DNR.
Chemicals, such as copper sulfate and sodium
arsenite, have been heavily used in the past for algae and
weed control, and there are now questions whether these
elements may have accumulated in bottom sediments to levels
that may be of environmental concern. Sediment sampling
is being done to assess potential problems. Use of chemicals
for weed and algae control is presently limited to small
areas, mainly for weed control along private shorelines,
and is generally conducted under the supervision of DNR.
DNR has established minimum and maximum
lake levels for the Yahara lakes. The Dane County Public
Works Department checks and regulates the lake levels by
making appropriate outflow adjustments. There is only a
six-inch difference allowed between summer minimum and maximum
levels, and it is very difficult to maintain lake levels
within this range. Lake levels are lowered for the winter
to prevent shoreline ice damage, especially on Lake Mendota,
and to store spring runoff from the watershed.
All navigable waters in Wisconsin are held
in trust by the state for the public. Many activities affecting
navigable waters and shorelines require permits or approvals
from the DNR. Some of the physical alterations to navigable
waters that require permits include: channel changes, riprap,
structures, grading, pipelines, sand blankets for improving
beach conditions, private bridges, dams, dredging and surplus
water diversion. Permits also may be needed from the U.S.
Army Corps of Engineers for filling wetland areas. Generally,
no permit is required for pier construction unless the pier
extends beyond a pierhead line or interferes with the rights
of the public or other riparian proprietors.
Local units of government also administer
regulations to control development along the shorelands
of lakes and streams and within floodplains. Shoreland control
is confined to lands within 1000 feet of a navigable lake,
pond or flowage, or within 300 feet of a river or navigable
stream (or to the landward side of the floodplain). Shoreland,
wetland and floodplain zoning ordinances often include:
restrictions on filling or dredging in wetland and floodplain
areas; permitted use of shorelands, floodplains and wetlands;
lot size; setbacks of buildings from navigable waters; tree
and shrub cutting along shorelands; and location and size
of waste disposal systems. County and municipal zoning administrators
should be contacted when activities are being contemplated
in these areas.
The Yahara lakes have a diverse and productive
fishery. The value of the fishery in numbers is striking.
More than 246,000 fishing trips have been projected annually
on Lakes Mendota, Monona, Waubesa and Kegonsa, with anglers
harvesting more than one million fish.
Lake Mendota is one of Wisconsin's most
popular fishing lakes. Generally, fishing for perch and
other panfish is outstanding both in the summer and in the
winter. Large- and smallmouth bass, northern pike, walleyes
and recently stocked hybrid muskies are present, as well
as a cisco population that has been increasing after a decline
that began over 40 years ago. Panfish are also abundant
in Lake Monona. Thirty-six species of fish have been found
in this lake, including walleye, muskie, northern pike,
largemouth bass, bluegills and sturgeon. Lake Waubesa also
supports a productive warn water fishery dominated by panfish,
but includes northern pike, largemouth base and some walleye.
Fish commonly caught in Lake Kegonsa are crappies, walleye,
largemouth bass, bluegills and perch. Stunted panfish, especially
bluegills, dominate Lake Wingra, although muskies have been
stocked and some largemouth bass are present. All the lakes
contain rough fish, such as carp and freshwater drum, that
have caused problems by stirring up bottom sediments.
DNR is responsible for managing the fishery
of the Yahara lakes. A major fish and lake management experiment
is being implemented on Lake Mendota by the DNR and the
University of Wisconsin. The project, known as "biomanipulation"
involves altering the food chain of the lake. A large number
of predator fish, such as northern pike and walleye, are
being stocked in the lake. It is hoped they will eat and
reduce panfish populations, which could correspondingly
increase the number of zooplankton (microscopic organisms)
that the panfish devour. Zooplankton eat algae and if zooplankton
populations increase, the amount of algae may decrease.
Thus, water clarity could improve, in addition to the sport
DNR also manages rough fish control and
harvesting on the lakes. Dane County is participating by
promoting and subsidizing additional harvesting of carp
and other rough fish. This not only benefits the fishery
but also helps water quality, since carp stir up bottom
sediments and recirculate nutrients.
Throughout the year, scientists from the
DNR collect fish from hundreds of lakes in the state and
test them for toxic chemical contamination. Each spring
and fall, they issue a health advisory that explains which
sport fish exceed health standards and where they were collected.
Lake Monona was put on the health advisory list in April
1987 after DNR experts confirmed that walleyes larger than
22 inches contained more than 0.75 parts per million (ppm)
of mercury. The allowable limit for mercury is 0.50 ppm.
At the concentrations found, pregnant or breast-feeding
women, women who plan to have children, and children under
15 should not eat walleyes 22 inches or larger. Everyone
else should limit their intake to no more than one meal
per month. So far, no other fish in the Yahara lakes have
been found to contain enough mercury or any other chemical
to warrant a health advisory.
The Yahara Waterways Water Trail Guide is a great resource for exploring our area waters.