Engineers Test Innovative Dredging to Save Kansas Reservoir
MANHATTAN, Kan. (AP) — Engineers launched a groundbreaking 10-day experiment Wednesday at one of Kansas' largest reservoirs, testing whether an untried underwater dredging technique can help reverse decades of sediment buildup that threatens the water supply for nearly half the state's population.
The U.S. Army Corps of Engineers and Kansas Water Office began the first phase of water injection dredging at Tuttle Creek Lake, a 63-year-old reservoir north of Manhattan that has lost about half its water storage capacity to accumulated mud and silt.
"We are excited to launch this first demonstration period for Water Injection Dredging at Tuttle Creek Lake," said Laura Totten, project manager for the Corps' Kansas City District. "This project represents a significant step forward in exploring sustainable dredging techniques to maintain water storage capacity and evaluate the associated environmental effects."
The demonstration, running through Sept. 27, uses a specialized barge to inject high-volume, low-pressure water jets into the lake bottom. Engineers hope the jets will loosen sediment and create dense, muddy water that flows naturally toward the dam's outlet gates and downstream into the Big Blue and Kansas rivers.
Picture three-and-a-half football fields with earth piled as tall as the Empire State Building. That's how much sediment flows into Tuttle Creek Lake each year. Since the lake was completed in 1962, accumulated mud has forced the marina to relocate and buried boat ramps.
The stakes are high for northeastern Kansas. The reservoir serves more than 40% of the state's population, providing water to cities including Topeka, Lawrence and Olathe. During drought years, stored lake water helps maintain adequate river flows for downstream communities and businesses.
Without intervention, the Corps estimates Tuttle Creek will be 75% full of mud by 2049 and retain just 7% of its original water storage capacity by 2074.
"We are about half full of sediment right now from the original constructed storage that we had there in the multi-purpose pool," Totten said in a radio interview. "So it is expected, but we're at a different time frame and we have a lot of demand for that water. We need to try to find a solution to try to sustain it for long term."
The water injection dredging method has never been tested in an inland reservoir, making Tuttle Creek a proving ground for technology that could potentially be applied to other sediment-choked lakes across Kansas and beyond.
In the 1960s, Tuttle Creek Lake was 30 feet deep under the mile-long Randolph Bridge, a popular boating spot. Today, mud flats are the norm at that location.
Engineers will monitor sediment transport, environmental impacts and operational efficiency during the demonstration. The U.S. Geological Survey, Kansas Water Office and Corps will collect water quality data from the Big Blue and Kansas rivers before, during and after the operation.
"We have tested the sediment within Tuttle for anything that could be harmful," Totten said. "Our scientific testing has shown there is nothing harmful."
Two additional demonstration phases are planned for spring and fall 2025, each lasting five days and focusing on areas within four miles of the dam.
Tuttle Creek Lake was built primarily for flood control after the devastating 1951 flood that inundated Manhattan, Topeka and Kansas City, causing more than $725 million in damages. The lake has prevented more than $12 billion in flood damages over its lifetime, according to the Corps.
The reservoir also supports recreational fishing for catfish, bass, crappie and other species, according to the Kansas Department of Wildlife and Parks. Tuttle Creek State Park at the dam's base features 1,200 acres of recreational areas, including camping sites, cabins and nature trails.
If successful, the innovative dredging technique could provide a cost-effective solution to extend the reservoir's lifespan and help address similar sediment problems at other Kansas lakes facing the same muddy fate.