Aquatic Habitat Program
F
lood control reservoirs aren't expected to last
forever. Rivers and streams inherently carry
sediment from the watershed. Banks erode, adding
more sediment. Many are expected to fill in just
100 years.
Conestoga Lake was no exception. Completed
in 1963, it had lost one-third of its original storage
capacity of 2,400 acre feet to sedimentation by
2013. The maximum depth had dropped from
more than 20 feet to 16. The west half of the
reservoir was less than 6 feet deep, and much of
the lake was 2 feet deep or less.
"Shallow, muddy, full of carp and gizzard shad
and powerboaters," is how Jeff Jackson, head of the
Commission's Aquatic Habitat Program, described
the lake.
"Essentially it was a mud bowl," said Aaron
Blank, southeast district fisheries manager for the
Nebraska Game and Parks Commission.
Fast forward to today, and you will find a lake full
of fish that is already attracting anglers in droves
thanks to an $8.5 million Aquatic Habitat and
Angler Access Program project that began in 2014
and was completed in 2018.
Most of the work involved addressing the
number one problem: sediment. With little deep
water remaining, and no aquatic vegetation
growing in the shallows, there wasn't much
habitat left for fish. Additionally, the sediment
also contained nitrogen, phosphorus and other
nutrients washed from farm fields that fueled large
algae blooms. "It was probably nearing the end of
its life expectancy as far as recreation sport fishery
at that point," Jackson said.
Roughly 600,000 cubic yards of muck, enough to
fill three-fourths of the bowl of Memorial Stadium,
was scooped from the lakebed. Most of the
sediment was removed from the bays on the north
side of the lake and the perimeter of the main arm,
increasing the depth of water within casting distance
of where most bank anglers fish to 10 to 12 feet.
Keeping sediment out of the lake and protecting
the shoreline was the second priority. The
Commission had built two-stage sediment traps
in reservoirs it had previously rehabilitated. At
Conestoga, they added a third, creating three
fingers that come from opposite banks that
Holmes Creek snakes around before reaching the
34 Nebraskaland • April 2022
A three stage sediment trap in the upper end of the reservoir will keep silt out of the lake and maintain water
quality, and also created wetland habitat for ducks, geese and shorebirds.
