Creating a Lake

[EddieWalker]

I have my rebar tied and my forms are ready for concrete. I went with 3/8's rebar on a 12 inch grid for the wall and every two feet for the angle. The footing is 3 feet deep and a foot wide. The wall is two feet tall and changes from 18 inches thick right at the top of the cement pad, to 8 inches at the top.

Tomorrow I'm third in line for the concrete truck. The forecast is for rain and it's increasing. I'm hoping that I'll be fine, but if it's gonna be close.

I'm estimating 7 1/2 yards. I'm adding extrac cement to the mix to get a 4,000 psi mix.

Eddie

 

[EddieWalker]

Change of plans. It was raining this morning and too muddy to get a concrete truck to where it needs to go. I'm thinking it's going to be a couple weeks until I can try again.

Eddie

 

[philbuilt]

I like your set up. 2 more feet of water will make the lake seem so much bigger.
Will that add about 3' all around? How long before it will rain and fill it up.
Phil

 

[jinman]

Eddie, sorry to hear about your delay. It's unfortunate that you have to deal with needing nearly perfect conditions to get a truck to your spillway. BTW, it's taken your picture for my old brain to visualize what you are doing there. After the pour, are you going to fill in the sides behind the cinder blocks?

 

[Western]

Eddie, sorry to hear about your delay. It's unfortunate that you have to deal with needing nearly perfect conditions to get a truck to your spillway. BTW, it's taken your picture for my old brain to visualize what you are doing there. After the pour, are you going to fill in the sides behind the cinder blocks?

I was wondering about a water " baffle" on the backside. Maybe thay is what will go there. Wonder if filling that void with large rock would work for a baffle and strength??. I know Eddie has a plan, just curious.

 

[jinman]

I was wondering about a water " baffle" on the backside. Maybe thay is what will go there. Wonder if filling that void with large rock would work for a baffle and strength??. I know Eddie has a plan, just curious.

Yep, maybe crushed rock or something similar in the middle. I was wondering about filling with dirt between the outside wing walls and the concrete blocks. Hydrostatic pressure is gonna push really hard against the cinder blocks if Eddie gets a big 4"-5" rain and that spillway is flowing pretty fast. I'm just not sure how Eddie plans to handle the transition between the spillway and the earthen dam so water stays inside the spillway and doesn't erode around it. Eddie has the width of a 2x4 above the main spillway for the wings, but what if the water tops this?

 

[EddieWalker]

I'm not sure if I understand the question. The cinderbloacks will be filled with concrete. There is already rebar inside of them to help lock them in position and add strength to the wall. The water will flow over the dam between the cinderblocks, creating two, side by side spillways. Across the top of the cinderblocks will be a six foot wide foot bridge.

I extended the cement dam 9 feet into the dirt and raised it 8 inches. My thought is that the water will take the path of lease resistance and only go so far along the concrete. This is all theory, and I counldn't find anything online to copy or learn from. Guess, Guess and more Guessing!!!!

The concrete is fairly stright on the water side, but angled on the back side. The wall is two feet and the bottom is 6 inchse out for a 24:6 pictch if roofing terms work. Again, this is just guessing on my part and what looked good eyeballing it. I want to water to flow over the dam and not just drop.

Where are you thinking the rock or gravel should go?

Eddie

 

[HiddenHollow]

Ed, I think they are talking about the space behind the walls on each end. There is a triangle of sorts between the wall and the wing of the dam. I belive they are concerned about all the force against the walls.

 

[EddieWalker]

Thanks. That will be filled in with dirt that will be brought up to the height of the bridge. The wings will be covered by dirt and not be visable when I'm done. I can't fill in the dirt until I remove the forms.

Eddie

 

[Western]

Eddie I was just curious about the area between the down flow, or backside of the dam/spillway, between the Block walls.

It may take some water over it to see how the hydraulics will work against the backside. That's why I wondered about the large (big) rock I've seen used to baffle the water on some Corps lakes overflow, or drain area to cut down on the hydraulics cutting back into the dam .

BTW, your walkway idea is super neat, should be handy for removing debris and inspection of the spillway.