Siltation may cause shortages by 2012


Deb Baker of the Kansas Water Office said supply and demand estimates cross referenced against reservoir conditions project permanent public water deficits by 2054.

Baker said Marion Reservoir, Council Grove Reservoir and John Redmond Reservoir supply most water in the Neosho River Basin. John Redmond is the largest with the most water.

Population projections from Baker’s office predict flat-line growth for Marion County through the years to the 2050s. In other words, population based on current data is not expected to grow or shrink appreciably.

Baker said everything in the research could be thrown off if one of the counties experiences unexpected growth. If all of Marion County’s efforts to recruit employers pay off with more people living here, there could be earlier problems to deal with at the reservoir, she said.

The City of Emporia in Lyon County is the only entity in the Neosho Basin expected to experience continuous growth, Baker said. Each county has different projections. Baker said Morris County, with Council Grove as its major city, is expected first to grow, then decline.

Baker’s data are based on a poor situation scenario on rainfall, to error on the side of caution. She said a 2 percent drought equal to that which occurred from 1952 to 1957 is used as the constant background.

The only ways available to improve the situation from KWO observations, Baker said, are reducing sediment flow into lakes, reallocating storage reserves, developing additional supplies—including, perhaps, new reservoirs—and dredging sediment from the reservoirs.

Of these choices, Baker said reducing sediment flow and dredging from strategic locations in each reservoir appear to be the most realistic.

Any of the choices involve great expense, she said, but building new reservoirs would be the most costly and the most upsetting to current uses.

“Besides that,” Baker added, “all of the really good locations for reservoirs were chosen the first time around.”

Some participants at the meeting said that if no conservation work had been done over the years on lands above reservoirs, many of the lakes would be filled already. Baker said the reservoirs were built for 50- to 100-year life spans with much of the work completed in the 1960s.

Phil Barnes of Kansas State University, who has been metering contaminant flows at Marion Reservoir this year, said he has been able to observe results of storms this spring and summer that were powerful enough to be in the likelihood of occurring only once in every 100 to 200 years.

This gave him high record daily inputs. On French Creek, for example, there were 4,400 tons of sediment, 48 tons of nitrogen and 15 tons of phosphorous. Plus this, he said, the lake had a high pH, which along with the load of nutrients, gives high growth conditions for algaes contributing to eutrophication.

Eutrophication includes the growth of plants that fill a lake to turn it to a swamp or marsh area. The plants may include toxic species such as the blue-green algae that has been a problem in Marion Reservoir, he said.

Researchers for the state and the U.S. Department of Agri­culture WRAPS program from the University of Kansas and Kansas State University also find concerns at the reservoir site. Their studies show high potential for cycling of nutrients from within the sediments of Marion Reservoir itself contributing to eutrophication and rapid erosion of banks.

Peggy Blackman, administrator of $499,073 in WRAPS grant funds, will travel the 200 square miles of the Upper Neosho Basin, which constitutes the Marion Reservoir watershed, to help agricultural producers initiate practices to slow sedimentation and nutrient loss. For the first time, this funding will include helping farmers adopt no-till crop practices.

The Marion County Commission also has included $50,000 in the county’s 2008 budget to provide the local contribution necessary to continue the watershed assessment study.

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