Do it yourself dredging equipment

[JAWISA1]

I am looking for instructions on how to build as underwater dredger/vacuum that is to be used for removing built up sediment from a local dive site in an effort to try to increase water clarity. Has anyone here attempoted such a thing? Any information would be appreciated.

Thanks

 

[dannobee]

I am looking for instructions on how to build as underwater dredger/vacuum that is to be used for removing built up sediment from a local dive site in an effort to try to increase water clarity. Has anyone here attempoted such a thing? Any information would be appreciated.

Thanks

There's a thread at thedecostop where someone asked the same question. There were quite a few answers and a lot of experience doing exactly the same thing. Search "water dredge" over there.

Be careful. Most were strong enough to suck up anything near them, including fingers and arms, without skipping a beat.

 

[coldsmoke]

I was thinking about doing as well. I found some really good info on the deco stop. Depending on how deep you are going an air lift might be a good option as well.

see this

Post your progress and results. I still want to build one to clean off an underwater bridge next summer.

Hunter

 

[Bob3]

Air lifts aren't my #1 (or #2) choice, a good pump is what ya need.
About how much sediment needs to be moved, and how far do you want to move it?
What consistency is the material? (sand, mud, gravel, stones, etc)

 

[muddiver]

Problem with an air lift is that they really only get the muck to the other end of the pipe, usually at the surface, it won't pump the muck and water anywhere and it will all rain back down on you.

A better setup is a venturi dredge. You need to build a pipe that necks down at the point that water under pressure is injected and then it goes back to the original size after the injection point. Attach a fire hose and it will move material suspended in water quite a ways away. The injection point also needs to point away from the suction end so you get flow in the tube. Provide a strainer that has holes smaller than the venturi section of your tube or it will plug.

Otherwise like Bob3 says, go get a trash pump and hope you don't drain the pond before you dredge out the muck you are trying to move.

 

[dsteding]

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[muddiver]

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[FredT]

Your site has a decent current a lift will work to distribute the sediment downstream, and is dirt cheap to build and operate, even it will bite pretty hard if you aren't careful. If your site has no current as in a quarry or lake a pump with a filter press or settlement pond is pretty much your only option.

BTW, Filter presses are EXPENSIVE!

FT

 

[JAWISA1]

Thanks everyone for the information. The site is an old quarry with no current to speak of so the best thing to do will probably be to dump it into a prepared loaction that will allow the sediment to be captured while allowing the cleaned water to re-enter the quarry. I may experiment with the home made system to check the viability on such a large site. The maximum depth would be around 50 feet.