Artificial Shoreline?

[Horton]

Has anyone ever engineered and effective artificial shoreline that mitigates backwash?

[Thomas Wayne]

I've seen some lake owners use materials from Goodrich, Goodyear, and Firestone - but I can't attest to the effectiveness.

TW

[Horton]

Yea  . . . No that is exactly not what I am talking about. Rocks, tires, sandbags. . . . not sure any of it is a good as correctly shaped shoreline. The question is there a good solution besides a tractor? I happen to know that we have a reader here that knows a lot about fluid dynamics (DW!)

[boarditup]

Yes.  There are multiple materials that can be used to various levels of effectiveness.  However, for the size of wakes we are dealing with the depth of the water for the shoreline is about 6-feet deep.  In other words, the depth of treatment is about 6-feet deep and then up about 2-feet above the resting water line.  The density, shape, and size of the material used will determine how well it will perform.  The selection criteria is based upon the slope of the ground and the composition of the substrate.  The typical best performers include geo-grid fabrics with stones to hold it down and filter the water as it recedes.

You are correct, a properly shaped shoreline in relationship to the substrate material is the best performer.

 Karl (www.placidwaters.com)

[RichardDoane]

SkiPark redid their shorlines prior to the 2008 Regionals.  Step 1 was use the Track-hoe to cut & pull back the grass, Step 2 was installing fairly large crushed rock.  Not quite as large as "rip rap".  The rock is from about 12" deep to about 12" above where the water breaks.  As long as they spray grass killer on the growing edge of the lawn, it won't continue to grow into the rocks.  Bounce back is now nill, and the lake skis really good.  However, the owners do not allow wakeboard boats, so the waves are only small.  As a skier walking out of the lake, you just have to be careful for the 2 steps it takes to get out and over the rocks.

[Dirt]

Horton, call Mike Martens at Bel Aqua. He is using some uv resistant plastic and rocks on top and rollers are non-existent. You will need a tractor and some serious labor especially for the islands. Is this for your lake? Call me. I do owe your family a bunch and I have a tractor.

[DW]

Rip rap / stones / rocks will work very well to break up the waves and break up the rebound.  Not the best to walk over though.  An other option would be a trench along the shore line to catch the rebound, this would be very sensitive to height and depth so not as easy as the rip rap solution.  Hard to keep in place but a semi pourous net would do a similar thing as the rip rap as long at there are multiple incident angles for the water coming through to break up the waves.

[eleeski]

My lakes started with an engineered 8:1 slope and no rollers. The clay banks eroded that away quickly and the rollers got bad. When the cattails started growing our water got perfect. The cattails were a perfect wake absorber. But after a few years the cattails got too thick and started reflecting rollers. Now there are lots of rollers. I need to remove the cattails and let them grow back - to just the right amount.

The best way to keep your lake smooth is to make it narrow. Even with poor shorelines, the rollers diminish a lot on reflection. If the lake is narrow, the wait for a reflection to pass and get perfect water is not too long. Wide lakes with jumps, islands and docks have lots of reflection points that take a long time to dissipate. The water always seems to move a lot on big lakes. But on my slalom bay - barely wide enough for a course - the water is perfect despite steep shorelines and no islands. Plus the wind does not affect the water nearly as much.  That headwind pass in smooth water is really nice.

175' wide (or narrower if cutouts for the turn buoys are engineered) will be the minimum size. The quality of the water will be excellent with any shoreline design. Plus you will need less water. A bigger separate jump lake will be needed for jump.

Eric

[Steven]

I don't know if you have any muskrats around, but muskrats like cat tails. If you get a muskrat burrowing in to your berm in the area where the cat tails are, all of the sudden you have a huge leak on your hands and a lot of repair work! Then you have to get rid of the muskrats. Your best bet would be to get a mini excavator and run down the shorelines and break out the walls of grass/growth and then follow up periodically with grass killer so clay doesn't get the stability of the roots from the grass. As long as there are no roots you will have the erosion effect and a nice shoreline. Then if needed you can add rock/10" minus (preferably river rock, kind to your tootsies) as this will stay in place and interlock nicely! The reason that I specify a mini excavator is that they are cheap to rent and light! An excavator allows you to point the tracks parallel with the shoreline there for minimizing impact on your berms(no back and forth turning motions). Also, it allows you to stay away from the edge of the lake so you won't get stuck and create a bigger mess! If you rent one, get the largest mini with the largest bucket and maybe one with a thumb. The thumb will allow you to pick up an I beam. This will give you the widest effective pushing area and do a cleaner job. Doesn't the owner of Iron Hood own one?

[AggieSkier]

I have seen Contech Armor Plate used for shoreline protection. Concrete blocks and steel cable make up a blanket.

http://www.contech-cpi.com/ess/products/contech_hard_armor/armortec_family/armorflex/220

 

Here is a picture of the lake http://search.har.com/engine/L-30-B2-Red-Oak-Dickinson-TX-77539_HAR6037881.htm

[kdeupser]

Guy's great info, got another one related to this one to throw at you.

 I ski on a friends lake that continuously fill's in with silt.  The lake is at the bottom of the sub-divisions watershed, and is continually hammered when it rains.  We try to blow out some of the shallow area's with the boat, but it still doesn't address the problem.  Some of the turn buoy's are only in 2 feet of water.  And if you stand up to walk out of the lake you will have leeches on you.  

Our initial thought was to use a siphon on the damn, then take one our boats and blow a spot and try to get the natural movement of the siphon to pull the silk down and out, but over such a span it just doesn't seem like it would work.

They have re-dredged the lake a time or two, but that is silly expensive.  We have thought about getting a worn out pontoon boat to use as a floatable pickup if you will and go turn buoy by turn buoy shoveling it back out, but this to is a pain.

Any idea's?

Thanks,

Ken

[Thomas Wayne]

I dealt with this by building a small suction dredge (7.5 hp), but it was still a hell of a lot of work to use.  Way easier than a shovel, however.  The upside is that the dredged area is still 5 feet deeper than it used to be, and that was 7 or 8 years ago.

TW

[eleeski]

My levees that are 20' wide don't get damaged by muskrats (30 years old). A 10' wide levee (with a lot of debris and brush buried in it) did fail from the muskrats. Reinforcing it to 20' wide with clean dirt solved the problem (10 years ago). Cattails are nice but not for every lake. They are taking over my old lake!

 

TW do you have plans for the dredge? Or a supplier? A broken pipe filled my boathouse with mud. Lisa won't let me get a new boat until I fix the boathouse!

 

Eric

[Thomas Wayne]

I just studied existing dredge designs and came up with my own configuration using off-the-shelf ABS plumbing pipe and plumbing fittings.  I went with 4" pipe, but for the slalom course issues described above I think i would up that to 6" pipe and a 15hp+ pump.

The principle is pretty simple, being just a high-volume discharge outlet fed from a venturi fitting that draws suction on a separate reinforced hose section.  For the venturi throat plate I used a large galvanized fender washer that necked 1 1/2" pipe down to about a 7/8" hole.  The resulting vacuum was surprisingly strong, and would easily yank a work glove off my hand under 5 feet of water(!)

Here's a link that may inspire your imagination:

http://nevada-outback-gems.com/design_plans/DIY_dredge/Homemade_dredge.htm

TW

(PS: If it can wait until April/May I think Brent E. is thinking about coming down to ski w/you, and I'm sure he's be able & willing to help with the boathouse.)

[Thomas Wayne]

 

I also found this diagram via Google, which may help you understand a suction dredge a little better.  This came from the Keene Engineering, Inc. website ( http://www.keeneeng.com - (800) 392-4653 ), which is a company in Chatsworth, CA.  You might contact them and see if they have suitable equipment for sale or rent...

TW

http://i115.photobucket.com/albums/n293/ThomasWayne_2006/SuctionDredge.jpg

[Steven]

Is there any chance of putting in a settling pond prior to entering the lake?

[eleeski]

Thanks TW. Come down with Brent! Of course if you want a new boat there, the boathouse needs to be fixed first!

Eric

[dougski]

Have ya ever heard of a yarder? they use  em for mining or logging will make short order of this matter . you'll have to remove your slalom course,It has a dragline bucket on it with two dozers one on each side one has pulley on it the other has spool a cable runs between with bucket attached.Let out slack bucket drags bottom pull material to ya spool side then tighten cable and send back to pulley side dig to grade and slowly move dozers down the berm.probably take couple weeks. you'll also need a support loader to haul off all the material.sounds like you guys got some serious cutting to do three to four feet.Going to cost some dough sounds like your lucky no one hasn't gone out front a broke a neck.Or you can use the vacuum cleaner idea.

[DW]

In the midwest many of the lakes are pretty much glorified swamps, they tend to fill with "muck" over time.  The muck is really decomposing vegetation (weeds).  A sludge pump is often used to suck out the muck and either move it or put it on the shore (muck basically turns to fertilizer in a few days once it dries out).  You can find these pumps at Northern Hydraulics and places like that.  Pretty much the same device TW describes. 

The pump has a 4-6" suction hose with a screen on the inlet and a long discharge hose to put it where you want.  They move a lot of water, but still not a low effort project.  At a minimum, I think I would start there.

I would also consider a settling pond, that is a very good idea.

Another device used for weed removal is a weed harvester.  Looks and operates like a combine, just travels on water.  Instead of a weed cutter at the front, you would need some way to burrow through the sand to get the material on the belt.

[Old MS Accout]

Here is how you fix erosion problems on turn islands.

Wait for 2 feet of ice, order rock and get it delivered. Move rock to islands.  

[Old MS Accout]

more

[Old MS Accout]

rock soild ice

[eleeski]

What's that white stuff? The salt around my lake never gets that thick!

Better way to deal with turn islands - REMOVE THEM! Safer and you can set down in the hole and not have to worry about getting around the islands.

And you will never have Imperial's problem...

Eric

[Old MS Accout]

I would love to dish them but we are only 2200 feet and it is very shallow on each end. We have a liner in the lake so maybe when we get a big hole we will drain and remove the islands. There is a minimum of 20 inches of ice, but it will go quick in March.       

[RichardDoane]

Eric - what's the problem with the islands @ Imperial ?  I skied around them just fine.  Oops - now I remember that there was an accident with a junior skier.

[Old MS Accout]

Eric is parinoid he will leave plaster on the rocks.

[eleeski]

No, I'm not talking about when I fell when getting up around the island for my 35 off pass at their tournament.

Someone hit the island and died a few years back (very old guy - not a kid). Details were unclear but Imperial lost a large lawsuit. Imperial has some of the widest skier paths around the islands. With expensive enough lawyers and mercenary experts, any case can be won. But no matter what if there is no island, it's hard to die on one.

Islands also get in the way of trick training. My lakes have no islands and are also 2200' long. No rollers from the ends and plenty of acceleration room straight in. Plus when I was farming fish, the nets were lots easier to manage without the islands.

Eric

[Old MS Accout]

JD and Dawgs lakes are island free. Nice cattails on the ends to eat up any rollers. It is great. The big plus on Dawgs lake is you get to drink Baileys and coffee everytime you ski.

[RichardDoane]

There needs to be a "BOS Invitational" at Dawgs lake!