Silt Removal/Dredging
 

So the canal I live on has a slow current through it and silt has been accumulating for years. There is about 2 feet to the silt bottom and the rumor is, the canal is actually 8 feet deep which I believe because I can push a kayak paddle with almost no resistance into the ground until it disappears.

I can currently get my Malibu through as well as the Wakesetter on the end of the canal, but I'd be a little happier with 4+ feet. Has anyone ever removed silt with something like a trash pump? I've found the piranha mini dredge (http://www.piranhapump.com/mini_dredges.html) which looks like it is a trash pump coupled with an "agitator" pump so you're not pumping dense packed sludge.

it's pretty pricey even used ones that I've found online so I was wondering if anyone has any experience before I make such an investment.

Thanks

if it's just fine silt and it's 2 feet down to it...no problem leave it alone.

It is fine silt, moves easy and we've done stump finding expeditions and have yet to turn anything up. The neighbors Wakesetter I know draws more water than my Sportster. I think I'm at 22" but I was under the assumption that was with a half tank of gas and 1 passenger. I guess there's not much risk if the prop is partially in the silt but when loaded I don't want the raw water intake taking in too much silt.

I might just put a crappy prop on my pontoon and turn it into a dredging barge.

You might be able to rent the equipment.

how big is the canal?

any regulatory agencies to worry about?

Roughly 30ft wide and ~700ft long, so that puts us at ~1555 yards of silt. We gotten "approval" that as long as all landowners agree, and no bucket loaders/excavators are used, it's considered shore frontage maintenance, IE they'll look the other way.

That sounds like a huge job that will consume a ton of gas/time.

Where will you dump the silt?

Time is the biggest part. It won't be an overnight kind of thing, most likely a lot of weekends in the fall. The dredge above can supposedly move 30 yards/hr so it would be a slow process. Late in the season the lake level can be lowered to as low as about 18" above the silt level. With people in the boat that puts the prop 6+ inches into the silt. Not sure if that is much of a concern but I definitely don't want to be sucking silt into the engine.

One neighbor has truck and dump access. We've also been in touch with local farmland who are willing to take it as long as we transport it.

1500+ yards is a lot of material to move for a few guys and some small equipment. You're talking about 300 dump truck loads. Just moving that amount even a short distance is going to cost some serious cheese in diesel alone. I moved 5 yards of dirt this past week the old fashioned way and it is something I never care to do again.

Holy lord my math was way off. I must have done some boneheaded conversions with dump truck sizes or something. Thanks Stanfield, that alone pretty much changes everything. I think the 50 dollar filter kit for the raw water intake is starting to sound like a better idea.

Also, those types of dredges are probably meant to move from 1 area in the body of water to another area. Pumping that into the back of a truck/trailer could be a problem as there will be so much water coming out with the silt. If 1 of those can really move 30 yards an hour (which I don't buy), that will be WAY more than you can keep up with having to truck it out, unless you had a small fleet constantly moving.

LOL ok. I was thinking this guy is a fool if he thinks he's going to move 1500 yards w/o some serious help. I don't think people fully understand how much a cubic yard is. You're average small dump truck will carry around 5 yards. The bed of your average fullsize 1500/150 will hold 1 yard, and if something heavy like dirt, will have your trailer hitch bottoming out over big bumps.

Yeah, fool indeed, I was an order of magnitude off of what this would entail. Math is fundamental kids! The sales people really do try to make it sound easy as pie "oh yeah, that thing will move 30 cubic yards an hour, and with some dewatering bags transportation shouldn't be to bad..." So unless I get the county to pony up for the removal, I'll just have to continue to blow the silt down the canal with the bu's prop.

I have no idea where you're at, but you might look into a professional service that does this sort of thing. If there is enough water around where dredging businesses can be supported, you might be able to find someone with a floating setup that would use a large pump instead of an excavator. If you can pump it out into the main body of water, it might be a "reasonably" priced alternative. Realistically you don't need the entire canal done, just a channel for the boats. Of course it's just going to fill up with silt again if water is moving, but might last a while. I know I definitely wouldn't be comfortable having to navigate in ~2ft of water every time I wanted to ride, but doing the job you described with you and your neighbors just isn't going to work.

just do some occasional flushing with fresh water to get the silt out of the motor.

The silt sure would bother me too...but that is a huge area. I was also thinking about moving the silt to the main channel by using an old outboard motor but 700 yards is a long way. I am glad you are getting by now as it looks like you are stuck with te problem.

I had a cance to build on a lake but it had a similar silt problem so I passed, someone did buy the lot and has an inboard but I just couldn't do it...and that was when I had a 17 year old DD.

You need to find someone that does manure management. It will cost you some $$$ but it would be the easiest most feasible route. We sell ag equipment and some of our contractors are hired out to do similar jobs.

[video]http://www.youtube.com/watch?v=Tl5Kf9fR4u8[/video]

Well, that would certainly do the trick Mark. It turns out that a different section of the lake has gotten approval from the lake board to have the DNR dredge it. While our canal wasn't included in the job, I had someone from the dredging company take a look at the canal for his assessment. He agreed that based on the location, hauling it wouldn't be cost effective, but he also said my math is way off in terms of area that needs to be dredged. He agreed that to keep the cost and labor down we don't need to dredge the entire width/length, just a channel for boat traffic, and a few hundred yards of material should do the trick. But even at a few hundred yards, still to much to haul. In our situation, he recommend what Stanfield said, to pump it back into the main body of water. Since there is an area that is already not passable by boats we could pump it there, and the lake will "redistribute" it. Most of it will end up back in the canal, but over years of time.

I do have to be honest, it freaks me out every time I see the neighbor's wakesetter cruise through what looks like 18" of water. But we've probed the canal and haven't found a section shallower than 40", it's just all the loose silt on top.

We have a similar problem in our lake, we get all of our water from a river that runs up to Dallas so every time it rains up there the water in the whole lake goes cloudy and you know that as soon as it clear up the lake just got that much shallower. Where our families lake house is under full pool it is only 2.5 ft deep, when the lake level was low we excavated a lot of it but it has already filled back in from the neighbors properties.

There is a large cove with a resort on the river and i hear it used to be 8-9 ft deep and now it is right around 2-3, when the lake is half a foot low or so you throw up a silt trail behind the prop while idling through there.