Long-awaited cooperative project improves Geneva Lake in Freeborn County
Note the clear water leaving the lake through the water control structure Ducks
Unlimited engineered.
After years of discussion, work completed to improve the water quality and aquatic
ecology of Geneva Lake in Freeborn County in southeastern Minnesota is clear to
see in the clean, clear water leaving the lake. Formerly held back by a fixed crest dam
that impounded both water and carp, Geneva Lake had been turbid for years and the
water was pea green. Now, after a temporary
draw-down of the lake via a variable crest water control structure engineered and
installed by Ducks Unlimited (DU) followed by chemical carp removal, the water is
clear to see again.
Geneva Lake is 1,875-acres in size, but averages less than four feet deep. A cooperative
agreement signed between Freeborn County and the Minnesota Department of Natural
Resources (DNR) in 2006 allowed DU to replace a fixed-crest dam on the outlet of
the lake with a variable-crest water control structure and fish barrier. The new
structure allows the DNR to manage water levels and greatly improve the wildlife
habitat benefits provided by the lake, and horizontal bars on the outlet now prevent
new carp from re-infesting the shallow lake.
“Using the
new water control structure to actively manage water levels will improve water quality
in Geneva Lake for both wildlife and humans alike,” said Jon Schneider, DU manager
of Minnesota conservation programs. “It is a real win-win partnership, and the participation
of Freeborn County Commissioners and local stakeholders was critical to our moving
forward this year.”
One of only 40 lakes legally designated by DNR for wildlife management purposes
in Minnesota, Geneva Lake is a 1,875-acre, shallow wetland basin with an average
depth of just over three feet.
Historically, the basin was too shallow to support fish populations
over winter and clear water and aquatic plants flourished.
However, warm, mild winters over the past decades coupled with
above-average rainfall since 1990 allowed carp and other invasive fish to overpopulate
and alter the lake’s ecology. The existing
fixed-crest dam, constructed back in 1953 to stabilized water levels in the lake,
further hindered water management efforts.
Water quality and wetland productivity declined dramatically
as a result, and the
lake became stagnant and of little value to wildlife.
Water quality leaving the lake was especially poor.
The start of construction work to remove the dam followed numerous discussions about
the degraded condition of Geneva Lake among local landowners and stakeholders, the
DNR, Freeborn County, the Turtle Creek Watershed District, and DU biologists and
local members.
“I’m really
looking forward to the improved water level management capability of the new structure
on Geneva Lake,” said Jeanine Vorland, DNR area wildlife manager in Owatonna. “Working
with Freeborn County, DU, the Turtle Creek Watershed District and local landowners
and stakeholders continues to be a real pleasure.”
Freeborn County, which granted DU permission to remove and replace the dam, retains
ownership of the new and improved structure. Freeborn County also granted DNR the
authority to manage the new variable crest structure to improve lake conditions.
DNR has established a local steering committee that will guide future Geneva Lake
water level management and improvement efforts.
The new
variable crest structure will be used to keep water levels about two feet below
normal pool level throughout the winter and into 2007. “Draw-down” management actions
like this simulate periodic droughts and winterkill conditions that reduce fish
numbers, consolidate sediments and rejuvenate aquatic plants and invertebrates.
A new fish barrier installed in the lake’s outlet culvert downstream of the structure
will prevent movement of fish back into the lake following managed winter draw-downs.
DU engineering for the Geneva Lake partnership project was supported by the combination
of state DNR duck stamp funds and an Environment & Natural Resources Trust Fund
grant recommended by the Legislative and Citizens Commission on Minnesota’s Resources (LCCMR) in 2005 and 2006 through the Habitat Conservation Partnership. DU subsequently
received $154,000 of federal North American Wetlands Conservation Act (NAWCA) funds
to pay for project construction. In
addition to the outlet structure work, DU is working with private landowners around
Geneva Lake to secure conservation easements to protect and restore sensitive shoreline and promote the USDA’s Wetlands Reserve Program (WRP). To date, several landowners
have protected their land with easements and other easements are pending.
“Enhancing and protecting Geneva Lake project is a huge
boost to DU’s
Living Lakes Initiative and the state’s Duck
Plan,” Schneider said. “With the support of partners like the Minnesota DNR and
Freeborn County, grants from LCCMR and NAWCA, and interest from local landowners, we hope to enhance and restore 300 shallow lakes throughout Minnesota in the future.”
DU and partners are actively delivering several other
shallow lake enhancement and protection projects throughout the state with Minnesota
Environment and Natural Resources Trust Fund grants through the LCCMR to the multi-organizational
“Habitat Corridors Partnership” (see
www.mnhabitatcorridors.org).
Many forms of wildlife will benefit from DU and DNR’s shallow lake work, especially
migrating ducks and wetland-dependent birds that rely on large marshes and shallow
lakes to replenish energy and nutrient reserves depleted during their long flight
through Minnesota in spring and fall. Several shorebird species and at least one
duck species, lesser scaup, are in decline continentally, and both state Trust Fund
and federal NAWCA funding is critical to improving and protecting the wetlands they
rely upon throughout their spring and fall migrations.
Previous Projects
Minnesota Land Trust - Private Landowners
U.S Fish and Wildlife Service - City of Kandiyohi