Marion Reservoir filling with silt, not water
Crisis in five years, no water in 50 years
Staff reporter
Think about this.
Within five years, there may be more demand for water than there is supply.
According to Deb Baker of Kansas Water Office, if there is another drought as experienced in recent years, those entities that use water from Marion Reservoir as their primary source may find the well running dry.
During a meeting Oct. 23 of Marion County Surface Water board members, Baker explained that within the Neosho River Basin, which includes Marion Reservoir, Council Grove Reservoir, and John Redmond Reservoir, water demands throughout the basin will increase while water in the reservoirs are decreasing, primarily caused by sediment.
"By 2012, if there is a two percent drought, demand will exceed supply," Baker said. And a two percent drought could occur again if history repeats itself. There were such droughts in 2002 and in 2006.
She continued that John Redmond, the largest of the three within the basin, is filling in the fastest with sediment caused by erosion and other factors. Council Grove and Marion reservoirs are smaller with slower sediment settling.
"By 2054, the water supply will not be sufficient," Baker said, which means in less than 50 years, residents in Marion County will not be able to draw water from Marion Reservoir.
So, what are conservationists and water authorities doing?
Past performance is used to project future returns. Unfortunately, there is no way to review peak supply and demand scenarios at multiple locations.
Dredging is an option but an expensive one at best. Baker said she wasn't sure if the reservoir could be used while being dredged.
Best management practices, a program offered by WRAPS (Watershed Restoration and Protection Strategy) to agriculture producers, continues to help decrease erosion along the banks of the reservoir to at least reduce the sediment load coming into the lake.
Other options include reallocation of storage within the reservoir and development of additional supply sources.
Building a new reservoir is out of the question, Baker said, because of expense.
Baker said the "end game" is to secure available storage with the State of Kansas paying for it, develop more sophisticated operations, provide or obtain better supply and demand information, identify storage and restoration opportunities, and increase funding of surface water issues.
A pilot study will determine if there is contamination in the top soil that is feeding into the reservoir. The water office will have conversations with officials in Oklahoma and Texas because they are experiencing similar problems.
Bathematric surveys will be conducted in Marion and Council Grove by July 2008.
Those surveys will track sediment in the reservoir. Instead of relying on outdated topographical maps and performing complicated calculations, this study will provide water officials with a clear picture of the amount of silt that has gathered in the reservoir.
Erosion issues
Erosion along the shoreline of Marion Reservoir is evident. Bare tree roots and even fallen trees are the most striking proof that the reservoir is filling with dirt and plant life.
Dr. Phil Barnes of Kansas State University, showed his study results following a heavy rain in May. With the rain came additional run-off of organic materials into the reservoir.
Monitoring was conducted at seven sites at the reservoir.
"Those thunderstorms in May were storms that we see every 100 to 200 years," he said. The area by French Creek was the most impressive.
Barnes estimated that 4,400 tons of sediment from French Creek alone since Feb. 1 have washed into the reservoir. Those sediments carried nutrients, nitrogen, and phosphorus. Approximately 48-49 tons of nitrogen moved with the water while 15.5 tons of phosphorus ran downstream.
"When (phosphorus) material gets into the reservoir, it can cause more cases of algae," Barnes said.
To monitor erosion along the lake banks, steel rebar is being driven into the banks. As erosion occurs, the rebar is exposed.
Former Marion County Commissioner Howard Collett commented that some county roads have been washed away and he wondered how much erosion from the roads have washed into the reservoir.
"I wonder what materials could be used on the roads to reduce road erosion," he said.
Marion County Commissioner Dan Holub said the county was aware of the problem and was looking for a solution.
