Shoreline Question

[Texas6]

Question for the Ballers. We groom our shorelines by box blade every few summers to control clifting along the shorelines. I'm considering knocking the cliffs down again and then lining my shoreline (about 5ft up) with bull rock to help control erosion. Being at the end of the lake with boats that spin, it's a constant problem. My fear is that if I line the shore with bull rock and the clifting still occurs, I won't be able to box blade it as easily. Pic attached, what say you? (Please ignore the crappy looking grass - it's a winter thing

 

[Horton]

Anyone from Sacramento want to explain what Tim did with rock on Bell Aqua lake 2? Think that lake is now bullet proof.

[A_B]

I would put rip rap in (large stones). We use 1's and 2's in these parts. See picture of my friend's lake, don't mind the fat guy on the platform. It was the best picture I had to share. No backwash, and he hasn't touched them since the initial dig. So about 5 or 6 years, not sure, I lose track of time.

 

 

[Texas6]

Thx @A_B - good feedback

[eleeski]

While BelAqua's rounded rocks aren't that comfortable to walk on they are a lot better than rip rap (broken up concrete). Eventually someone or some boat will hit the shore (both have happened multiple times at my lakes). I have hit graded soil and cattails without serious injury and without boat damage. Rounded rocks might be painful. Rip rap could injure you or tear up your boat. Is your occasional grading that bad?

 

Eric

[Texas6]

Fair question Eric. It is a pain, some of which is my doing with sprinkler lines running where the box blades need to run, and sprinkler heads which were ten feet from the shore, now about to fall in the lake. My shore deteriorates at twice the rate as others due to where I am which makes grading necessary far more frequently. I suppose I could buy my own tractor, move my sprinkler lines, suck up the expense and do it myself or continue to rent out the work at $250 per grade....just thought possibly there was an easier longer term fix than a box blade

[boarditup]

You have other options. If the grade is 10:1 or even flatter 16:1 below the water, the wakes will lose most of their energy before it gets to the shoreline. You can use sand for the shoreline without erosion. If you have slopes that are steeper, then you need to have the energy absorbed by the shoreline above the waterline. If you put down some geotextile fabric that prevents the rocks from descending into the soil, you can use a much smaller rock. As another alternative that I have not used, but have seen, you can use astro turf (same as on football fields, not outdoor carpet) starting below the waterline and up beyond the wash line for the wakes.

 

As for the kind of geotextile fabric and the size of the rock, you need to know the slope of the shoreline and what kind of rock is available. The geotextile vendor can help without hiring an engineer.

[ToddF]

Not sure how well it would work, but your could groom/fill it in then put a liner in at that section, the liner would keep the contour, backfill the liner a bit to hold it in place. If you lower the lake in the winter it would be easy to access

[A_B]

The #1 and #2 rocks were just that, not broken up concrete from highway tear outs. Rounded stones could work, although, I think they are a bit more expensive, plus I am not sure they are as readily available as the rocks. My friend had a person being towed behind his sister's boat going around the turn island, pull out too wide and ended up taking a tumble on the rocks. I think he broke a finger. Although, your could break your neck in sand too.. We never use the turn islands for slalom work, but assume most course skiers would know how to take the turn. The guy who fell was on 2 skis or maybe one skiing recreationally once in a blue moon. The rocks eliminate erosion and don't have to be 16:1. I think his are more like 10:1. From your picture, I would just fill in from there and let them run out and up onto the grass. Some stone quarries now sling them into place, and you might be a good candidate for that.

[Texas6]

Great points A_B - makes me want to consider a beach ....if I can figure out how to keep my sand and keep weeds out of it

[mrpreuss]

I don't like the look or feel 60" up is necessary, will 18-24" do the job?

If so do that.

Some on my lake have what you are considering and I think it's awful.

One has rocks just where the waves hit.

It looks great and has been in the longest with no erosion.

[bishop8950]

I am not an expert, but have been working on the shoreline out club lake for a few years. Just a few points from my perspective.

 

It really depends on what you have to start with. Lake to lake is different and at our lake the shoreline has different material all around different parts of the shoreline.

 

I agree with @boarditup. If you have the right slope sand works. We have 16:1 and did a 250' beach area with sand and it lasted nearly 15yrs before you started to see the base. I recently added 6-10" of sand and expect another 15 years. It seems to stay in place. Shortline (Elk Grove) did this even longer ago and it held up nicely.

 

At one end of our lake we have all hard clay and the lip/cliff was tough. Given how hard the material is grading it doesnt seem to be an option. So there we used the same filter fabric and rocks Bell Aqua used (same contractor as well) to line the shoreline and it is now bullet proof.

 

Some other areas have a bit of clay mixed with sand and gravel. I removed the clay with a tractor and put back sand or gravel and it seems to be holding very well.

 

What has worked for me is to experiment. Do a trial on 25-50' of shoreline and see if something works before making a big commitment to labor and or materials.

[Marco]

When we first built our lake, we initially tried erosion fabric, thinking it would hold vegetation which would prevent erosion. When that didn't work, we brought in 6 inch minus river rock, and went about 2' below waterline and 1 foot above. It works great and it isn't to much rock to navigate when getting out of the lake

 

[MrJones]

I have a clay based soil that started out as 10:1. There are some areas that are starting to cliff, so I looked at number of things this winter and went up with what is locally called 1x5 rock. I used my tractor/bucket and (along with my kids) we basically filled in the base of the cliff creating a new slope.

 

The 1x5 is smaller, but much less expensive as well. Bull rock looks great, but the expense ruled it out. The local rip rap was huge and knarley looking. Will let you know how it works out after a few months of skiing this summer.

[bishop8950]

Additional comments

 

1) at our lake weeds are best controlled with herbicides like it or not. Dye helps. Any growth on the shoreline will increase clifting, unless you go all out with cattails or something similar. Filter fabric unprotected by a solid layer of rocks will not last.

 

2) my understanding of filter fabric is to keep the base shoreline in place. Rocks take most of the abuse but water still passes past them and pulls the dirt/base out of your shoreline unless you have a filter fabric to hold it back. Rocks on dirt can overtime still erode buy pulling the base out and watching the rocks sink.

[The_MS]

We have a sand shoreline and use this devise to grade the tops down.

 

[Not_The_Pug]

@bishop8950 is correct with Bell Acqua Lake 2. The whole lake is lined with filter fabric to keep the rocks from sinking into the clay and be eroded from behind the rock. Because of the clay it was really the only option to keep the rock in place and not have the shores shelf. We have not had an issue since it was done.

[Texas6]

@MS, I like that contraption of yours. Question for you about your sand shoreline. You obviously have a very flat shoreline (16:1?). We are 10:1 at the Lakes of Katy and mine seems to be steeper than that for some reason. If I graded 5-10' of shoreline down to a 16:1 grade right at the waters edge (after lowering the lake level, do you feel I could keep sand in place? I assume you guys are using a heavier aggregate?

[The_MS]

I did not do the design but we are at 15:1 and have a liner in place. We use large rock for our turn islands but the lake is primarily sandy rubble bottom with the shorelines mostly sand. Its like Minnesota lake sand. We made the drag with some fencing and green treated lumber. Keeps the weeds rooted up and the lips of the edge down. We have about 5-8 feet of sandy shore around the whole lake and that gives way to grass.

[Texas6]

Thx a million Ballers

[elr]

Maybe just removing the grass a few feet up from the water's edge would help -- seems to work at Cypress and Bennetts, but I don't remember what they do around the turn islands.

[boarditup]

Wakes are traveling waves. Think of a sine wave drawing with the zero being the water surface. When you have a gentle slope under the water line, the pressure from the wave pushes the wake upward and spreads it out - typically the crest of the wave will begin to curl over and then flatten out. This dramatically dissapates the energy that can cause erosion. The particle size of the soil also has a huge impact on the rate of movement and erosion. Clay and slits are very small particles and will erode and move quickly. Sand is a much heavier particle and stays put better. Rock, depending on size is better, but it reflects more energy back into the body of water. Rooted plants will cause "shelfing" as the water erodes the soil around them and will reflect wave energy back into the body of water and cause rollers just like a seawall.

 

Fabric with rock on top will avoid most erosion. You can use smaller rock and even sand to make the rock walkable. Peastone is great for this. However, if you do not have fabric to separate it from the substrate, you will lose all of your small rock very quickly. If you have sand that is fine, you can put some peastone in the sand to hold it in place a bit better. The stone will sink down, but you will find that it will "resuface" as it does its job. You will loose smaller sand particles over time.

 

So, you first have the proper underwater slope and then amend the top layer as necessary to give you the best option for avoiding reflective wave energy and erosion. The best solution is the below water contour. The depth from 0-3 feet is the most critical. The waterline to the potential wave height is also critical. The longer and more gentle the underwater slope, the less out-of-the-water height is necessary.

 

[boarditup]

You would need stone an 8:1 slope. Sand would be to mobile. Large particle size sand (gravel) stays put at 10:1. Fine sand (beach sand) needs flatter.

[mt17085]

Great info! Currently rebuilding an 8:1 slope on clay. @A_B Thanks for the great pic! The rock looks great. How thick? What is the slope? Did they put fabric down first?

@bishop8950 You said you put fabric and rock on one end of our lake with hard clay... what was the slope?

[mt17085]

@Marco Great pic. When you changed to river rock did you leave the fabric in place? What was the slope?

@Krlee What was the slope at Bell Aqua 2 where the rock and fabric was placed and has worked so well? Thanks!!!

[Marco]

@mt17085 - Yes we left the fabric in place. It helps to keep the clay from eroding around the rocks, and gives the vegetation a place to root. Our shorelines are 10:1

[bishop8950]

@mt17085 our slope probably was originally 10:1 around the islands. At be more. I bet when we rocked it it had eroded to less, somewhere between 8-10 : 1?

[rawly]

Thanks for all of the good information . we will be rocking our shorelines this spring . We will be putting down 2.5 " rock on 5 of our 6 shorelines ( Ski West Village ) . The total price will be roughly 40 K including material and tractor work . Adding an extra 5 K for the fabric seems like the way to go . The one price that I got was 11 cents per square foot . After reading through this thread , it seems that the route to take would be to add dirt where we have cliffing , get our grade back , throw down the fabric , then cover with rocks . Any feedback would be greatly appreciated . Our lake is down now , so there are roughly 3 feet of exposed shoreline that will be covered when we bring the level back up .

Thanks Steve

[rawly]

Thanks for all of the good information . we will be rocking our shorelines this spring . We will be putting down 2.5 " rock on 5 of our 6 shorelines ( Ski West Village ) . The total price will be roughly 40 K including material and tractor work . Adding an extra 5 K for the fabric seems like the way to go . The one price that I got was 11 cents per square foot . After reading through this thread , it seems that the route to take would be to add dirt where we have cliffing , get our grade back , throw down the fabric , then cover with rocks . Any feedback would be greatly appreciated . Our lake is down now , so there are roughly 3 feet of exposed shoreline that will be covered when we bring the level back up .

Thanks Steve

[bishop8950]

The fabric is critical and the cost is incremental. In fact, you might argue that it saves money given the shoreline will last longer and the rocks won't move so you could use less stone for the same benefit.

 

I would grade first if you can just to give you clean slate and flat basis for the fabric and rock. You can however rock right over a lip as long as its not too big. Bell Aqua did. I graded most of our shore before rock but where the hard pan was brutal we left it and used more rock for the desired result.

 

Here are some pics of a small section we repaired using fabric and 4-6" crushed stone. The close up has maybe 70% of the stone down

 

 

Here is another section (all the way around one island) repaired the same way

 

 

[Tim Vaio]

At Bell Acqua Lake 2, we spent much time determining what we should / could do. We had various opinions and ideas and wanted to line the turn areas and east side of the lake with rip rap and sand the west side of the lake. We ultimately decided to rip rap the entire lake and build 3 walkout areas on the west side.

We purchased fabric, lined the shoreline and then place the rip rap on top of the fabric. With then did the same to the turn islands. One of our members came up with a great idea on how to transport and drop the rock perfectly in place on the islands and it worked easily.

We did this 7 years ago and the lake skis fantastic and has not degraded during that time. The downside is that for tournaments you need to swim to one of the walkout areas to comfortably exit the water. We also then spent considerable time improving the common area with grass, irrigation landscaping and structured water quality treatments.

The rock we used was not round river Rock because our experience was that it did not stay in place and required regular maintenance. I can send pictures and specifics on the size rip rap we used, the amount and the rough cost if interested.

Our results have been great.

[rawly]

Thanks for the replys. I will pass this on to our board members. Pictures and the info would be very nice Tim. Post them here or you can e mail them to Charlie. He will be involved in this project. Thanks

[thompjs]

@rawly

The fabric is very important. Sometimes the rock without geotextile under it will cause more turbulence as the wave hits the shore and thus more erosion.

[Skoot1123]

@tvaio - what was the grand idea of getting rip rap to the island? I'm all ears for our lake.

[Tim Vaio]

One of our members designed a really effective floating cart. I can describe and also can post a picture soon. We built a raft that was plywood covering some old foam we had from our jump ramp. The raft was approx 4 ft wide by 6 ft long. The top deck of the cart was plywood and around the exterior of the cart was 2x4 on the deck which created a border. Then vertical on one side of the raft we built a tower approx 6 ft tall. The tower was built simply with 2x4 and then horizontally the tower was connected to the opposite side with long 2x4 (envision it created a rectangle on top of the cart).

This allowed us to stack rip rap on the deck of the raft. We then were able to float the raft and pull it to the islands from the shore. Once at the island we then had a rope attached to the top of the tower and were able to pull it towards us which in essence tipped the raft over and dumped the rip rap in 6 ft wide sections perfectly where we wanted it. We would then pull the raft back to shore and do all over again. We only lost one load of rip rap in the lake from overloading it. This allowed us to work very efficiently and more precisely with how much and where we dumped the rip rap .....

[Triplett]

I unfortunately do not have any pictures but we had a similar problem at our lake years ago. I do not know the size, but we put small field stone around the lake to eliminate this problem (the rocks fit in the palm of your hand for the most part). We just dumped the rock, no fabric, and haven't had any issues in 15+ years. The bottom and shorelines are all sand as well. They are not the most friendly for climbing out but we have no erosion or backwash issues. We have about 15-20ft of rocks since out water level drops quite a bit from spring to fall.

[skiep]

 

[Skoot1123]

@tvaio - yes please send pictures! We have a pontoon boat - but capacity is only 1,000 lbs. and the loading/unloading of the pontoon boat is also an issue as there isn't any easy way to do that. Thanks.

[Tim Vaio]

Will do tomorrow with some pictures

[eleeski]

Better solution, get rid of the stinkin islands! Less rock, erosion and backwash. Plus safer and better for tricks.

 

Eric

[Skoot1123]

@eleeski - aren't tricks for kids? No tricks on our lake - yet.

[rawly]

Hi guys , it's me again. Because of the large amount of rain this spring , we put off our project until this fall. We are either going with the larger rock you see in this picture , or 2 1/2 - 1" gravel. Which can have a larger percent of the smaller 1" pieces. Our thoughts are to put down the fabric if we go with the smaller gravel and scrape the surface to get rid of the ledge or fill with dirt before the fabric goes down. Will the fabric keep the fill dirt from moving ? Should we stick with the larger rocks 4-6" ? Does the smaller gravel need the mesh ? Thanks guys.

 

[ripa38]

The 1" rock will not stay in place. It will wash back into the lake within one year. Giant waste of money. We have already tried that. Have the board look at the rock on the east side of Adobe or the west side of Paradise lake 2. It's the bigger 2-3" and it stayed in place. Can even compare the bigger rocks on SWV lake 3 west side.

[rawly]

Any thoughts ?

[Marco]

Totally agree with @ripa38 . The smaller rock will not stay in place. We used rocks in the 6" range, and we still need to tune them up every spring when the water is low. 1-2" rocks will just get washed away. We haven't had any more clifting since we installed the larger rock, many seasons ago.

[bishop8950]

We did a small section with crushed stone around 1” and it’s holding better than I though, but is moving. The larger section with 4-6” stones is solid and going no where. Definitely use filter fabric.