Silt Wars
Casitas Municipal Water District’s rejection
of disposal plan threatens dam’s removal
By Daryl Kelley
The Casitas Municipal Water District refused Wednesday to endorse in concept disposal of 2.1 million cubic yards of silt behind obsolete Matilija Dam to a storage area above the dam, an alternative favored by county and federal agencies.
Casitas directors, on a 3-2 vote, refused to grant conceptual approval to an alternative proponent recommended to rescue the troubled $155-million dam demolition project by moving it along more quickly and for much less money.
Two other silt-removal alternatives had turned out to be either more expensive than expected or were blocked by uncooperative private property owners.
Casitas’ approval of the new alternative was considered essential because federal money, the bulk of the overall project’s funding,- cannot be pushed through Congress without Casitas on board, project backers said.
Conceptual approval by Casitas would have enabled federal officials to gain about $4 million needed to complete a final design of the project, backers said. About $4 million has already been spent on such studies.
But most Casitas directors said Wednesday that they did not have enough information to commit to the new alternative, even conceptually.
They said they needed to be convinced the project would not harm the quality of water in the huge Lake Casitas reservoir or interfere with the district’s federal mandate to assist migration of endangered steelhead trout.
They asked for more study, saying they felt they were being forced to make a decision prematurely or to take the blame for killing the overall project.
Indeed, after the vote, county and federal officials said Casitas’ position puts the entire project in jeopardy, because delay will allow scarce federal funds to go elsewhere.
“The project is at more risk now than it was before this vote,” said Ventura County Supervisor Steve Bennett, spokesman for groups favoring the newest alternative. “I remain committed to finding a way to overcome this setback, but this decision makes it much more difficult.”
Directors Russ Baggerly, Pete Kaiser and Richard Handley said they wanted more study before they could commit to the new storage concept, while Directors Bill Hicks and Jim Word voted for conceptual approval because of warnings that the project could die from delay.
Baggerly, frequently an ally with Bennett on environmental issues, said he had to break with the county supervisor this time, partly because he did not want to see a permanent silt storage area built in Matilija Canyon. Perhaps the silt could be stabilized above the dam by mixing it with soil, he said.
Baggerly said the new alternative would accomplish none of the goals set out by groups that have worked for more than a decade to remove Matilija Dam, which has been nearly filled with silt and sediment since the 1960s.
The alternative would not restore the Ventura River to its natural state, he said, nor would it bring sand to Ventura beaches, enhance recreational opportunities or assist migration of the endangered steelhead trout.
“We don’t necessarily have to jump into this today,” Baggerly said, complaining that Casitas had only weeks to study the new alternative, which is poorly defined so far.
“If we get our heads together we might be able to work something out,” he said. “But this dog won’t hunt … There are other alternatives.”
He asked Bennett and representatives of the county Watershed Protection District and the U.S. Army Corps of Engineers to bring in experts to answer Casitas’ questions about what might happen to the stored silts during heavy flooding and to study whether some of the silt stored in the canyon might be released over time, instead of placed in a de facto “landfill” permanently.
“I don’t want to endorse this preliminary idea until it is more thoroughly vetted,” Baggerly said.
A Corps of Engineers spokesman, Darrell Buxton, told the board that its approval would pave the way for a more complete analysis of the Matilija Canyon storage alternative.
“This is a conceptual design,” he said. “With your concurrence, we’ll go forward and answer a lot of these questions.”
Board member Hicks said he didn’t think Casitas had much choice.
“If we’re going to lose this funding, then where are we?” Hicks said. “If, in fact, the funding is going to go away, this is the lesser of three evils.”
But Baggerly, joined by Kaiser and, finally, Handley disagreed. They approved an amended statement of the Casitas position that called for more study instead of endorsing the behind-the-dam storage alternative.
“The proposed concept may have elements that could prove to be beneficial,” the Casitas statement said. “And, in the spirit of collaboration, there may be other ideas on the subject that may also prove to be useful.”
But, after the vote, Bennett said the county had no money for studies and that the Corps of Engineers had a very limited budget for such analysis.
So, Bennett said, Casitas’ position could derail removal of Matilija Dam, which had been on a fast track in Washington but could now be shunted aside in favor of other federal projects that are ready to go.
“After the millions that have been spent, Casitas asking for more expensive in-depth studies when they are not willing to even conceptually support the proposal likely dooms the project to the decades-long slow track,” Bennett said Thursday morning.
“The Army Corps has hundreds of underfunded projects,” he added. “Why would they spend their scarce dollars on expensive in-depth studies if the Casitas board is not willing to even conceptually support the proposal.”
Baggerly’s response was that it would have been “bad government” for Casitas to endorse so sketchy a proposal.
“Casitas told them publicly that if they could demonstrate that the fines (silt) could be stabilized upstream permanently, we could live with it,” he said Thursday. “To date they have not been able to answer one single question. The only answers we have received are ‘We don’t know,’ or ‘We will have to look at that.’”
Baggerly said project backers need to revisit an alternative embraced six years ago, to pump slurried silt from behind the dam to the Baldwin Road area, where it would have been spread along the Ventura River to wash downstream during storms.
The cost of that proposal skyrocketed from about $30 million to more than $50 million, so project backers looked for cheaper alternatives.
Baggerly said the Baldwin Road plan might be used in conjuction with other alternatives.
“Just as they have come up with a new concept,” he said, “I believe there may be some combination of concepts that may work.”
Man-Made Lake Saved from Strangulation
For the past 15 years, residents of privately-owned Lake Tishomingo have watched their lake slowly deteriorate from a gradual buildup of choking siltation. As the problem grew in magnitude, they explored the possibility of obtaining government assistance, but finally decided to take matters into their own hands before it was too late. Homeowners in the community leased a Mud Cat™, a portable dredge, together with accessory equipment, and within a few months they were winning the battle.
Lake Tishomingo is a 120-acre artificial lake located southwest of St. Louis, Missouri. Its name is derived from an Indian word for “healing waters.” Developers envisioned the newly-created lake community, built between 1947 and 1950, as the perfect setting for “vacation living every day,” with a short 30-mile commute to the heart of St. Louis.
In the wake of postwar development, forested lands near the lake were cleared for farms and residential areas. Tishomingo has a natural watershed system and the removal of virgin ground cover increased topsoil runoff, causing silt to built up on the lake bottom.
A water quality problem resulted from the accumulating sediment, which produced an over-abundance of aquatic weeds. Together, these problems made boating impossible in some areas, limited fishing, and caused a water pollution problem.
For more than a decade the Lake Tishomingo Property Owner’s Association tried to solve their problems by drawing the lake level down about four feet each year between October and December.
During these drawdown periods, excavators attempted to remove sediment build-up from coves, using bulldozers. Although some sediment was removed in partially dried out areas, the bulldozers could not operate in the soft, mucky silt. The lake wetlands were also too soft to support other heavy equipment.
Attempts were also made to remove silt from the main channel with draglines, but there was little progress: the dragline bucket stirred up the silt and caused turbidity. The silt, in suspension, would simply separate itself in the lake, causing additional problems.
Finally, members of the association formed a silt removal committee and charged it to solve the sediment problem. Jewel Lindsey, a Tishomingo resident for more than five years, was named chairman. He reports, “Our only objective was to get the lake cleaned and restored. Members of our committee traveled to neighboring states, studied a variety of on-site cleanup alternatives and reported their findings.”
Committee members also looked at conventional dredges, but concluded that they were too expensive and too large to operate in the shallow areas and numerous small coves which needed dredging. Residents also turned down the idea of drastically lowering the water level for entire summer to accommodate draglines, front end loaders and bulldozers.
One reason for rejecting this clean-up method was that the lake rests on relatively thin rock formations which could crack under the weight of the heavy equipment, causing openings which might drain the lake. Also, during the long drawdown period envisioned, the residents would have virtually no use of the lake. They also feared that Lake Tishomingo would not be able to replenish itself after the cleanup. There had been a recent history of low rainfall in the watershed area.
Eventually, a member of the committee read about the Mud Cat™, a small, portable dredge marketed and sold by Ellicott International of Baltimore, Maryland. It appeared to be the best alternative from several standpoints the cleanup could take place without lowering the lake: residents would still be able to enjoy all their summer water sports; and the machine was small enough to operate in the shallow, heavily silted upper end of the lake. The Mud Cat™ could also perform selective dredging in the long, narrow coves which contained from one to two feet of silt.
As compact as it is – 8 feet wide and 39 feet long – the Mud Cat™ is equipped with a 175-horsepower Detroit Diesel engine. This motor drives a pump capable of removing up to 120 cubic yards of sediment per hour. Its auger can cut out up to 18 inches of silt per pass in depths to 15 feet below the surface of the water.
The key to the effectiveness of the dredge is the eight-foot wide auger attached to a hydraulic boom at the front end of the machine. A mud-shield surrounds the auger minimizing turbidity. As the auger rotates, it cuts out and feeds the silt deposits to a center intake tube where the material is sucked up by the pump, which provides the energy to propel the silt, suspended in water. through an eight-inch diameter discharge pope over distances up to 3,000 feet to a designated disposal area.
On the Lake Tishomingo project, the Mud Cat™ is being used with two additional booster pumps to deliver the sediment through approximately 9,500 feet of pipeline to the disposal area on a nearby farm. There are three levels to this disposal area, which act as individual containment ponds for the sediment as it moves across the land. The sediment settles out onto the field and the water runs off over a controlled spillway structure to a nearby stream.
The quality of the disposal area runoff water is constantly monitored by the Missouri Clean Water Commission. Samples are taken regularly by the Lake Tishomingo project superintendent and submitted to the commission for testing. Clarity of the water being returned to the stream has been termed “excellent,” indicating that the disposal area is permitting settling of virtually all silt.
The long pipeline which carries the silt to the disposal area is required to pass over both land and water. It is coupled together in 39-foot long sections.
The pipe (Driscopipe 7600) is composed of ultra-high molecular weight, high density polyethylene. It conforms to the steep ground contours without disturbing property owners, thanks to the tight leak-free joints. The pipe ran across the surface of the lake supported by special floats. Steel flanges were added to protect the pipe from wave actions caused by passing boats.
Boat accessibility from docks to the main recreational areas of the lake is maintained by removing floats from the pipeline, allowing the unsupported section to sink two to three feet beneath the surface. This permits boats operating at reduced speeds to pass over the pipe safely.
More than 80,000 cubic yards of sediment have been removed from the lake bed. Fishing areas that had been silted over are showing signs of coming back to life. A swimming beach near the community center was badly silted over; now it’s clear, clean and suitable for water sports. Boats that have been in storage for several years because of the siltation are back in the water. The lake looks as it did 20 years ago, according to Lindsey, who adds that there will be a continuing effort to see that it stays that way.
start slow they did it
12 Feb 10 at 10:10 am
great find starts slow I am glad the board voted to wait on this one. We need to look at all options and not one that is being rammed down our thoat.
now is the time to get creative
12 Feb 10 at 12:06 pm
It was a good story. Sounds like they really worked together on it.
A slow steady inexpensive (relatively) start sounded better than doing nothing at all. Maybe start with a temporary smaller solution until they get it figured out and that way it’s easier to correct mistakes and redirect potential problems without a catastrophe.
I’ll help! Bring my bucket and pantie hose?
start slow they did it
12 Feb 10 at 3:51 pm
There is no good reason to tear down MJ dam. It still functions as a reserve and holds back over a million cubic feet of water year round. That water leaches into the water table and provides for Miners Oaks wells. It supports an ecosystem of fish, turtles and birds. Tearing down the dam would leave carnage from MJ to the sea.
It took 60+ years for that lake to fill half full of silt. 100 years from now it will be a slowly eroding waterfall. So why spend $43 Mil in this economy? O-right, to bring back non existent steelhead…
No dam spending
12 Feb 10 at 4:56 pm
It’s going to happen so you might want to get on the solution side and try to help keep the animals and fish from experiencing a holocauste or Haiti incident.
Maybe if they suck out the silt gently the beauty of the lake will make them reconsider the entire tear down or at least allow the wildlife to move on due to a mild disruption.
I’ve seen cool pictures of one horse powered wagons before the dam, it’s a really neat gulch. And won’t it be cool to hike through there with new water holes and stuff?
start slow they did it
12 Feb 10 at 5:33 pm
4 million on studies??? I could have removed the dam turned a 2 million profit: 2 million to condemn and buy land below dam (eminent domain), 500,000 in tnt, and 1.5 million to truck silt to local beach communities. They could buy the silt for 6 million.
Who says the Truth Coalition does not produce solutions?????????????????????????????????
Anon.5
13 Feb 10 at 8:32 am
Let Mosler Rock mine it and remove one million Cu Yards a year and it will be clear in 3 years. Mosler is already regulated with Fish and Game County and state water and air quality departments and the Gravel trucks from over the hill won’t need to come thru Ojai. Too easy. Too cheap and not political enough to mess it up. Won’t work for sure. We need to waste vast amounts of money to solve easy problems. Why spend Hugh amounts to haul it away when the silt and rocks can be SOLD and give the taxpayers a break. Why not take some of that material and rebuild the levee down at Burnham and get the people out of the flood zone?
anonn
14 Feb 10 at 9:34 am
This was a good idea five years ago, when the economy was booming and unemployment was 5% and the government had plenty of taxpayer revenue. Now, not so much.
Just Another Taxpayer
14 Feb 10 at 5:39 pm
Tear down the wall – Tear down the wall – Tear down the wall….
The chant of crazy people…
Truth Coalition
16 Feb 10 at 5:25 pm