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Archive for Sunday, October 28, 2007

Silt crowding out drinking water in reservoirs

Two-thirds of Kansans rely on man-made lakes

Mark Jakubauskas, a research associate professor for the Kansas Biological Survey, and Frank "Jerry" deNoyelles, KU ecology professor and associate director, survey bank erosion Friday at Kanopolis Lake southwest of Salina. Sedimentation has many top Kansas officials concerned about the future of Kansas' reservoirs, which are filling up with silt.

Mark Jakubauskas, a research associate professor for the Kansas Biological Survey, and Frank "Jerry" deNoyelles, KU ecology professor and associate director, survey bank erosion Friday at Kanopolis Lake southwest of Salina. Sedimentation has many top Kansas officials concerned about the future of Kansas' reservoirs, which are filling up with silt.

October 28, 2007

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Sedimentation in Kansas' Reservoirs

Sedimentation has many Kansas officials concerned about the future of Kansas' reservoirs, which are filling up with silt. Christine Metz reporting. Enlarge video

Dividing up water in a reservoir

Dividing up water in a reservoir

— By midafternoon, luck strikes on Kanopolis Lake for three Kansas Biological Survey scientists.

It's a crisp autumn day. The water is slightly choppy. Waves spill into the boat. The scientists wear windbreakers, flannel shirts, work boots and ball caps.

A grin - wide and excited - spreads across Mark Jakubauskas' face.

"This is awesome," he says.

On the computer screen in front of him are layers of colors - blues, greens, yellows, oranges and the occasional reds. To most they would mean nothing. To Jakubauskas, they are the reflections of sound waves that ping from the boat to the bottom of the reservoir and back to the boat. Over the course of two days, they will send 200,000 of these pings through the water.

In the moment the grin appears, Jakubauskas is looking at a computer screen showing a steady line of red across the middle. A few inches above it are some yellows and oranges.

The sonar has just captured the original bed of the reservoir, which before the dam's flooding in 1948 was the valley floor. The lighter colors above indicate the amount of sediment that has collected since the reservoir was built.

With a few pings, Jakubauskas estimates there is about 8 feet of silt accumulated beneath them.

The crew has been waiting all day - actually more like months - for this kind of easy-to-read data. Without it, they would have to use decades-old topographical maps and do complicated calculations.

But, here it is, in an instant, clear as a picture - just how much silt has gathered and how big of a problem Kanopolis Lake is facing.

Since this spring, Jakubauskas, KU ecology professor Frank "Jerry" deNoyelles and Scott Campbell, associate director of the KU Field Station, have spent days in this sturdy, aluminum fishing boat, turned research vessel. They have mapped the silt on about a dozen reservoirs in Kansas. Much of their work is funded through the Kansas Water Office.

The data indicate how much storage capacity the reservoirs have left for drinking water and flood control. And, if the time should come, the numbers will help establish how much sediment needs to be dredged from the bottom.

Their findings are important to state officials, who will spend the next half-century determining what to do to keep Kansas' aging reservoirs vital.

Inevitable

DeNoyelles stands along the shore of Kanopolis Lake. An eroded bank looms above him. Dirt sifts through his hands. This, Kansas' fine-sandy soil that eons ago was an ancient inland sea bed, is the problem, he says.

Kansas isn't like Minnesota with its granite rock locking in glacier melt to form lakes thousands of years old. By nature, lakes aren't suppose to be here.

The soil, which so easily washes from farmland and river banks, is carried by shear hydrologic force downstream. That is until the water reaches the mouth of the dam, where it slows. As the water settles, dirt drifts down to the bottom of these man-made lakes. Over decades, feet upon feet of silt stack up.

If nature has its way, someday - in 200, 300, 400 years - the reservoir will disappear.

"It is inevitable. That is the striking thing about it," deNoyelles said. "These reservoirs, this reservoir that we are looking at right now is going to fill in in a century."

The problem is, Kansas has come to depend on those reservoirs. From small farm ponds to Milford Lake, with its 163 miles of shoreline, the state has thousands of them.

When the U.S. Army Corps of Engineers began building reservoirs in Kansas - starting with Kanopolis - it was to provide flood control. They later became sources of public water supply, irrigation and recreation. Today, two-thirds of Kansans and much of the eastern side of the state rely on reservoirs for drinking water.

Even when they were built, the reservoirs were given lives of 50 to 100 years. Just a year shy of 60, Kanopolis has approached and passed middle age. Many others will follow in Kansas and in other Great Plain states, which will face the predicament of dirt displacing water.

The drought that has hit the southeastern United States - and panic over the declining drinking water in reservoirs - highlights the importance these bodies of water have on public welfare.

The sedimentation coming into the country's reservoirs has to be incorporated into long-range planning, said Michael Hayes, director of the National Drought Mitigation Center at the University of Nebraska-Lincoln.

"If you are an official and not considering that, then you are missing something," Hayes said.

Just a few days before the Kanopolis expedition, Kansas Water Office Director Tracy Streeter stood in front of a room full of state legislators, department heads, federal bureaucrats and water experts at the Dole Institute of Politics. He threw out a date: 2012.

Five years from now, the supply for water in southeastern Kansas' Neosho River Basin is expected to smack straight into the rising demand. And, if the region were to experience droughts as severe as those in the 1950s, there would not be enough water in storage for everyone who wants it.

For every year after 2012, it takes a little less drought for the water supply to dry up.

The largest of reservoirs in the Neosho River Basin is John Redmond, where almost half of the space needed for drinking water has been filled in with silt. The Kansas Water Office estimates that the amount of sediment settling in the lake each year would cover 2,075 acres a foot high with muck.

Smelly water

From the stern, deNoyelles guides the boat across Kanopolis Lake. He looks between his Global Positioning System and Jakubauskas' screen, which has red, ribbonlike lines charting the lake.

As he steers, deNoyelles talks about another project under way with the Kansas Biological Survey. Just as weather patterns are studied to forecast annual crop yields, deNoyelles said he is trying to look at weather and water conditions to estimate algae growth. The information will help in predicting water quality.

Long before reservoirs fill with silt, another problem surfaces. More sediment means shallower lakes and fertile growing grounds for algae. More algae means tarnished drinking water.

It's nothing poisonous and it won't make people sick. But, the water will have a musty, earthy, fishy taste, deNoyelles said.

"Really, all of our reservoirs are at some stage of having a problem with the taste in our drinking water," deNoyelles said.

Lawrence's water supply has had "taste and odor" problems from the algae growing in Clinton Lake. Assistant Director of Utilities Philip Ciesielski said he couldn't say if it had anything to do with the lake's increasing sedimentation.

Upstream from where the city of Lawrence pulls water out of Clinton Lake, sits the water intake system for Shawnee County Rural Water District No. 8. In the years after Clinton Lake formed in 1977, the district noticed the water quality decrease as sediment built up around one of the lines drawing water. Within a decade, the line was abandoned, general manager Dennis Schwartz said.

In the next 10 to 25 years, another line - this one higher in the lake - could be threatened by silt, Schwartz said.

"We are in the upper reaches of the reservoir. So we probably are seeing, witnessing, the first negative aspects of sediment accumulation," Schwartz said.

The solutions

From the bow of the boat on Kanopolis Lake, Campbell gives an overview. Call it Kansas Reservoirs 101.

The lesson: There is no easy answer on what to do to keep the reservoirs viable.

"If it were easier, we'd already know what to do," Campbell said.

Walter Aucott, director of the Kansas Water Science Center and with the US Geological Survey, told the crowd at the Dole Institute that efforts to shore up river banks and stop water runoff haven't been working as well as they had hoped.

The federal government hasn't built a dam in Kansas for 25 years. Federal agencies at the Dole Institute made it clear that building reservoirs isn't as simple as it used to be. They now have to factor in endangered species and environmental impact studies.

And, all the prime spots for reservoirs are taken.

Raising the level of the dam for some reservoirs could mean flooding out parts of towns and cities.

Dredging is an expensive proposition. DeNoyelles estimates to dredge some of Kansas' lakes could take up to a $1 billion.

Even if money was there to pay for the dredging, there has to be a place to put the uprooted silt and there are environmental impacts. When the sediment is dredged, pollutants are stirred up and the lake's habitat is disturbed.

The view

For the past decade, deNoyelles has been sounding the alarm on the rising sediment levels on the reservoir bottoms, his colleagues said.

State Rep. Tom Sloan, R-Lawrence, credits part of his concern to deNoyelles and Ed Martinko, director of the Kansas Biological Survey. The gathering of state officials at the Dole Institute was Sloan's idea.

For Sloan, a major question is who will pick up the tab for the changes needed in the reservoirs.

This year the state will send the federal government about $2.5 million so it can store water in its reservoirs. Sloan would like those annual payments to come straight back to Kansas. And, another tax - a few cents per 1,000 gallons - might be needed on drinking water, he said. He also thinks the fishermen, boaters and beachgoers should help out.

"If (we) do nothing for the next 10 years, we are going to be OK," Sloan said. "But the ultimate cost is going to be much higher. I believe it is better to pay a little bit today and prevent a crisis tomorrow than it is to try to address a crisis when it occurs."

As the boat bounced across the top of Kanopolis Lake, the pings at full throttle and the sun shining, the rising sediment seems far below the surface - out of sight and easy to ignore.

Then the image of the rock bottom covered in feet of sediment pops up on Jakubauskas' computer screen, bringing the problem into full view.

Comments

BigPrune 7 years, 1 month ago

Of course the lakes are filling with sediment. Everyone of them is muddy.

Start the dredgers and do the Kaw while you're at it.

just_another_bozo_on_this_bus 7 years, 1 month ago

If we can just continue to increase our population by 2% (minimum) per year, God will miraculously cure our imminent water shortage. You just gotta believe.

LogicMan 7 years, 1 month ago

Stop studying (a.k.a. "hand wringing"), and start dredging ("doing the real work").

The material brought up is excellent -- dry it, bag it/bulk it, and sell it to us for our gardens and farms.

just_another_ninja 7 years, 1 month ago

And somewhere, some football team is 8-0 for the first time since 1909. Great lead story.

On topic... somewhat ... I heard that there was once a city at the depths of what is now called Clinton Lake. I wonder if their technology can see what remains, if anything.

Kristine Bailey 7 years, 1 month ago

Why does no one ever mention the watershed ponds around Clinton Lake? I personally own one that is 10 acres in Osage Co. And the property next to mine has one as well. They are built to be the first silt catchers before the water enters Clinton Lake. Did they do this around Kanopolis Lake? Why do they never report the proactive measures in place? Why doesn't Mr. deNoyelles mention this to reporters?

Write2Know 7 years, 1 month ago

Increased ethanol consumption is only going to make the water situation worse as farmers irrigate more and more corn.

jayhawklawrence 7 years, 1 month ago

Like Rancho, I was surprised at the lack of information regarding what has been done in the past to alleviate the problem. I was the National Sales Representative for an erosion control company based out of Rossville, KS. I attended many conferences sponsored by the IECA (www.ieca.org) and gave quite a few seminars of my own on the topic. We had a great product, home grown and admired by Civil Engineering companies and city/county engineers in many states. Eventually, I had to leave because there was little interest in aggressive Erosion Control measures. It seemed to me that the only time states like Kansas want to invest any money is when the EPA starts threatening to fine them. During this period in my career I started switching my political philosophies away from the Republican party. I sensed that there is a lot of big money politics going on in the Transportation departments at the State and Federal levels which is not in the best interest of the average taxpayer. There are a lot of good innovative Erosion Control products available now and the companies that are supplying them are struggling to get them into the market. Don't get me started on the Ethanol and Coal companies use of water resources in the Aquifers.

Bladerunner 7 years, 1 month ago

Ninja, That mysterious underwater town is not Atlantis but in fact the old Clinton.....Hence the name.

just_another_bozo_on_this_bus 7 years, 1 month ago

From what I've heard, dredging the reservoirs would actually be more costly than their original construction was. And if/when global warming creates drought conditions, if there is no rain going into the reservoirs, it won't matter if they've silted in.

Joe Hyde 7 years, 1 month ago

"...and while you're at it dredge the Kaw, too."

Can even one proponent of this idea please explain how dredging the Kaw River has any impact on the depth of sediment that is relentlessly accumulating on the lakebeds of upstem federal lakes?

50YearResident 7 years, 1 month ago

I hear that dredged sediment from the bottom of lakes is not good soil for any agricultural use for at least 10 years. Does anyone have information about this?

monkeyspunk 7 years, 1 month ago

Erosion control should continue to be a priority, but another issue needs to be addressed and that is consumption. What percentage of water consumption is used for watering lawns, golf courses, and ball fields? I like the green as much as the next person, but I would imagine the percentage is pretty staggering. Also how much of an impact does urban runoff have in comparison to rural/agricultural? Is urban runoff even relevant to the discussion?

Also, I will look myself, but does anyone knows how much water Corn cultivation uses in comparison to a crop like switch grass.

monkeyspunk 7 years, 1 month ago

"The amount of water needed to produce crops varies considerably. Perennial prairie grasses such as switchgrass are native, hardy, and drought-resistant. They require far less water than intensive row crops. Similarly, jatropha bushes, a source of biodiesel, can survive dry conditions and poor soils. Other grasses require abundant rainfall to thrive. (In the U.S. about 15% of corn acreage is irrigated.) Of course, areas with low rainfall will be less productive than those with higher rainfall. For economic reasons, however, projections of biomass crop production do not include land that needs irrigation."

from http://www.energyfuturecoalition.org/biofuels/benefits_ag_rural.htm

Time to get off the corn band wagon. Damned Hawkeyes.

countrygirl 7 years, 1 month ago

I thought it was the town of Bloomington that is under Clinton Lake.

just_another_bozo_on_this_bus 7 years, 1 month ago

It's not a hope-- just reporting what I've heard, RT. And it does make some sense if you actually think about it (I know that's asking a lot of you, RT.)

When the reservoirs were built, they were mostly dry land. They are now completely under water. If they drain the lakes so that it can be dredged more easily (and cheaply) then the water source is gone for a long period of time-- likely years, not months. If you don't drain, then the dredging operation is incredibly expensive, since all the material you want to remove is under water, and bulldozers, scrapers and dump trucks don't work so well under water.

gccs14r 7 years, 1 month ago

We should be discouraging people from moving to Kansas and especially to Lawrence. The last thing we need is more folks drinking our shrinking supply of water.

jayhawklawrence 7 years, 1 month ago

I would also like to see a study on how much erosion is natural and how much is man made. From what I have seen, the biggest source is erosion caused by construction activities. These activities, until recently, have never been regulated in regards to erosion. As a result of federal legislation, the EPA has been given authority and funding to clean up the nations waterways and deal with the erosion issue. Under the Bush administration, the EPA's authority to monitor and enforce the clean water act was challenged in the court. The issue was whether the EPA's authority only covered "navigable waterways". The Supreme Court basically ruled in favored of the Bush supported plan to decrease the EPA authority to implement clean water policies. The silt fencing and hay bales you see in ditches and at construction sites are there because of the EPA enforcement and education activities. Kansas has been one of the states which is slower to respond to the new EPA guidelines. The problem of urban runoff is a different problem. It is a major source of pollution which is the other thing building up in our groundwater and waterways and source of increased flash floods which also increase erosion problems.

jayhawklawrence 7 years, 1 month ago

A lot of states blow mulch over a construction area because it is cheap and they can say they are using erosion control methods and avoid fines, etc. The first big rain or wind the mulch blows away and the soil starts eroding. Or they call the rip rap company that is owned by the big construction companies that come in and dump a bunch of rock for $40 a cubic yard and call it erosion control but it does not filter any pollutants and is not a natural solution. It also washes out over time in most cases and you end up with a lot of unsightly weeds coming up through rocks that also collect garbage such as tires and bottles. So they make a ton of money on tons of rock dumped in our ditches and along our streams. Meanwhile a lot of small new companies introducing native plant and turf reinforcement solutions are kept out of the loop. These products have been proven to hold up under high velocity water flows but they compete with the big quarries (Prime contractors) and sometimes require more money but not always. I guess what I am saying is that there are a lot of people who don't want this issue investigated too thoroughly so it will be quietly swept under the rug as in the past.

Write2Know 7 years, 1 month ago

You should have seen Mt. Mangino erroding away at the Baylor game.

ralphralph 7 years, 1 month ago

Dredge Clinton, use the silt to fill the Baker Wetlands and build the SLT on it.

badger 7 years, 1 month ago

For those of you cavalierly tossing out, "Just dredge it!" like it's some sort of easy solution, did you read the part of the article where it talked about a $1 BILLION price tag for that? It's not terribly feasible or realistic as a solution, if for no other reason than that it would have to be an ongoing process, with redredging every fifty or sixty years as the reservoirs silt up again.

Of course, that's not even considering what's in that soil: pesticide residues, fertilizers, heavy metals, industrial runoff. It'd take a lot of 'soil washing' (a very water-intensive process) to make that soil usable for anything.

To a certain degree, erosion control will help, as would a shift in focus to crops that require less intensive irrigation. Conservation, though, will be the big deal as the supply dwindles. Put in low-flow showerheads and get a high-efficiency front loading washer. Use targeted drip irrigation on a dawn/dusk timer instead of sprinklers, and plant drought-resistant ground cover instead of water-sucking lawn grasses. We cut our water consumption over 80% in one year with under two hundred dollars' cost outlay (incuding the difference between the high-efficiency washer we bought and the one we'd have bought otherwise, because our washer was d-e-d and being replaced either way) and about thirty hours' worth of work.

The big, shiny technical solution that doesn't require you to make any lifestyle changes only exists in fiction, guys.

hujiko 7 years, 1 month ago

Nothing remains of any town under Clinton lake, the Corps bulldozed everything before filling it in 1977, besides, it wasn't much of any town, just sparse farms. Richland was a small town that was demolished when they decided to build the dam, but it lies above the lake in Shawnee County and has never been underwater.

Toto_the_great 7 years, 1 month ago

The state of Illinois used silt from the Illinois River (one of the most polluted rivers in the country thanks to the sewage released by Chicago) and created parks near Peoria. The public thought it was great, but I think overall the project had moderate success. If I remember correctly, the plant species diversity didn't reach target goal: but they pulled out a lot of sediment (only to have in deposited in there from row crop agriculture).

Another problem with dredging is the release of the toxins that accumulate in the silt. I don't think I would want to be drinking the water from there after the dredging (or use the soils for my spaghetti squash).

The majority of silt from ag states (e.g., Kansas) comes from row crows, which is why some farmers are practicing no-till farming (don't really know the success on this topic). Those pretty orange (or black) silt fences you see construction companies use are just piece of mind to the public. They don't work at all.

John Redmond Reservoir near Emporia has almost filled with silt. These artificial lakes (e.g., Redmond, Clinton, Perry, etc.) fill with sediments because dams slow the water velocity and the silt has time to settle. I say blow the dams and let the waters flow into Missouri or Oklahoma and let them worry about it.

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