A muddy classroom chair, car floor mat and bike were among the recovered objects sitting along the shores of Potter Lake last week.
Nearby, crews were working to suck up thousands of cubic feet of sediment that had deposited in the pond during the past 50 years. The $125,000 dredging project, which began several weeks ago, is intended to restore health and beauty to one of Kansas University’s most iconic landmarks.
The project might also help answer the decades-old question of what exactly lies at the bottom of Potter Lake.
Leading the effort to pull mud and lost treasures out of Potter Lake is Mark Hannah, a project manager for Stream, Lake and Wetland Solutions, the company working on the project.
Hannah is also a 1971 KU graduate, who swears he isn’t looking for anything in particular.
“I have nothing prized or condemning in there,” he said.
On Thursday morning, Hannah’s crews came across what many suspected they would find.
At first the workers thought they had run over one of their hoses at the bottom of the lake. Upon closer inspection they realized it could be nothing other than a goal post.
Over the years, a few have been rumored to have disappeared into Potter Lake.
“Other than that we really haven’t found anything of any significance,” said Jim Modig, director of design and construction management at KU. “Most all of it has been branches and sticks.”
The lake, which will turn 100 next year, has been dredged only one other time in its history. In that instance, the lake was drained first. This time around the process is a little less intrusive.
“It’s the arthroscopic version of dredging,” Hannah said.
Filtering the water
Last week, crews were operating a small boat, which held a piece of equipment that Hannah calls a snow blower on steroids. Using 1,200 gallons of water a minute, that equipment chews up the sediment off the bottom of the pond. The silt is then sucked up into hoses and pumped to giant bags, which sit in a catch basin below the lake’s north side.
The liquid in the bags is injected with a polymer that separates the sediment from the water. To help speed the process, workers smack the bags with large sticks.
Crystal clear water leaches from the bag and into the catch basin. That water is returned to the lake.
The whole process is to restore the pond’s natural depth and to remove nutrients that have washed into the pond over the last half-century.
In recent years, seaweed-looking plants called coontail overcrowded the lake and green, grainy watermeal covered the surface.
During summer 2009, the lake reached a crisis point. Heavy rains led to a burst in plant growth, which sucked oxygen from the water. As a result, hundreds of fish died.
The restoration of the lake is in large part due to the efforts of the Potter Lake Project, a student group that has rallied around preserving the lake.
A year ago, the students were holding cleanup days, bribing other students with food to get up early on Saturdays to use pitchforks to clear the lake of its mountainous amounts of vegetation.
“It was a lot of manual free labor,” said Matthew Nahrstedt, a KU architecture student who is co-president of the Potter Lake Project.
While the students had an end goal of dredging the lake, the group anticipated having to wait years before raising the money needed to do it.
But last spring, funding from KU’s Student Senate Finance Committee, the Office of the Chancellor and KU Endowment allowed the project to move forward. Another $200,000 from the American Recovery and Reinvestment Act provided money to reduce the amount of stormwater runoff coming from Jayhawk Boulevard.
“It’s a dream,” Nahrstedt said.
Already, the north side of the lake has cleared of watermeal and more is expected to die after the first freeze. By spring, the lake should look like many people remember it — clear and beautiful.
“It unfortunately has been something to walk by, but we really feel this is a unique part of KU. Not a lot of campuses have a natural landmark like we do,” Nahrstedt said. “And we need to protect that.”
The dredging should be finished in the next two weeks. In all, 5,000 cubic yards of dirt are expected to be removed from the lake.
The dirt, which sits drying in giant bags, will be used for topsoil or backfill.
But before that happens, Modig said someone might want to take a metal detector over it.
He suspects they might find a few class rings or even a diamond one.