problem figuring out how to "lower" a fall from upper to lower pond

[lachancesare]

Ok...I sought help previously about this but still have the problem.
I have a two level pond setup with a cascade above the upper pond.
My problem is that with the pump running, I continuously lose water when pump pushes water from top pond to lower.
After repeated attempts to find a leak in either cascade or either pond...I am convinced the loss occurs because the in between falls is to high to allow the upper pond to move sufficient water to lower.
here is my conundrum:
When I built the ponds, I repurposed an 18" stone/concrete wall as the wall for my upper pond....when I planned the fall from upper to lower ponds, I put cinder blocks at the falls, under the liners, so I'd have a flat falls surface.
I did not allow enough depth for enough water to leave upper pond.
Question:
How can I do something to reach and remove/breakup/lower those cinder blocks??!!
There are 3 layers of epdm on top of the blocks (one layer to prevent puncture, the lower pond liner, and the upper pond layer)
I tried to use a rubber mallet but to no avail. I am resigned to trying to reach a way to "peal back" the upper pond liner by removing about 9" of mortared stone on each side of the falls to be able to peel back the upper, then lower liners, get under the "puncture proofing layer" and remove or break up the cinder blocks. But I fear it will be more problematic getting things back together to look right.
Any magic ideas on how to achieve this????
I am attaching g a couple of pics for showing the problem area.
Any and all suggestions appreciated!!!

 

[Lisak1]

So just to clarify - you feel the area which is supposed to create a falls between your two ponds is too high, so the upper pond won't flow into the lower pond? And the water level gets too low too fast for the flow to continue between the two ponds.

If I got that part right, I'm guessing then the upper pond WOULD eventually fill enough to start flowing again, but the rate at which the water is being pumped from the bottom to the top is too slow to keep up. Do you see where I'm going here? There is math involved with the problem you have - I don't know what it is and when we built our pond we just crossed our fingers and hoped for the best (and used a variable speed pump, just in case!)

As it stands, I see a few options. 1. Increase the size of your pump to pump more water to the upper pond faster. 2. Decrease the size of the outlet for your falls (reduce that opening with some well placed rocks and a bit of waterfall foam), meaning the waterfall would flow slower but the upper pond would have a chance to stay full or 3. add a second pump in the lower pond pumping to the upper pond into a second area in your pond - you could add a stream or even just a well concealed pipe. The advantage to #3 would be more water circulation, which is usually a good thing!

You may also want to/need to try a combination of all three to strike just the right balance.

Someone else (who knows that complicated math!) may chime in here and tell me I'm all wet (ha!) with my suggestions, but that's how my mind has worked your problem out!

 

[lachancesare]

Actually....the pump is filling the upper pond faster than it can flow to the lower pond, causing the upper pond to "overflow" (i.e.water rises above upper ponds liner level, causing water to seep out over liner but behind mortared stones.)
I tried slowing flow but if I slow it ....water still is lost...just more slowly

 

[Meyer Jordan]

The way I read your problem is that the water level in the upper pond is getting too high before sufficient water can flow over the cascade into the lower pond resulting in water loss voer the liner edge in the upper pond. If this is what is happening, besides your solution, you have maybe two (2) other. Your real problem appears to be that the weir between the upper and lower pond is not wide enough for the current water flow. You can restrict this water flow or the better solution would be to widen the weir assuring that it is level from edge to edge. The latter solution would allow you to maintain your current water flow.

 

[lachancesare]

The way I read your problem is that the water level in the upper pond is getting too high before sufficient water can flow over the cascade into the lower pond resulting in water loss voer the liner edge in the upper pond. If this is what is happening, besides your solution, you have maybe two (2) other. Your real problem appears to be that the weir between the upper and lower pond is not wide enough for the current water flow. You can restrict this water flow or the better solution would be to widen the weir assuring that it is level from edge to edge. The latter solution would allow you to maintain your current water flow.

Meyer....I tried that already. The real problem is that the weir is too high (and those darned cinder blocks under the liners at the weir do not allow me to lower it.)

 

[Meyer Jordan]

Meyer....I tried that already. The real problem is that the weir is too high (and those darned cinder blocks under the liners at the weir do not allow me to lower it.)

Then your only solution is the one that you feared. You need to demo the existing weir and rebuild it at the proper height and width.

 

[cas]

The real problem is that the weir is too high

Help me understand. How does having a too high of a falls cause the upper level to overflow? And why wouldn't creating a larger opening help in moving the water faster out of the upper level so it wouldn't overflow?
My falls is a little high and I loose water from a lot of splashing, but not from overflow.

Is there a way for you to raise the sides of the upper pond?

By the way, very pretty pond.

 

[lachancesare]

Then your only solution is the one that you feared. You need to demo the existing weir and rebuild it at the proper height and width.

Meyer....thank you for confirming my worst fear....lol
one other question:
In researching rubber sealant, I found one that is clear and can seal cement and stone.
I have asked the dealer to let me know if it will work to seal from the liner below water level up and over it over the mortared stone....wish me luck in getting a positive reply!!!

 

[lachancesare]

Help me understand. How does having a too high of a falls cause the upper level to overflow? And why wouldn't creating a larger opening help in moving the water faster out of the upper level so it wouldn't overflow?
My falls is a little high and I loose water from a lot of splashing, but not from overflow.

By the way, very pretty pond.

Cas
with the pump turned off....I do not lose water.
when I broadened the "weir" from upper to lower, and turn pump on, I still lose water.
with the pump oof, the upper pond level is exactly the weir level.....earlier I did an extensive check of the cascade above the upper pond. I also removed stone around the upper pond at any perceived lower perimeter.
the problem is at the weir.

 

[cas]

Thanks. After I thought about it for a few minutes I figured that was it. Is there anyway to raise the edges of the upper pond?

 

[Meyer Jordan]

Help me understand. How does having a too high of a falls cause the upper level to overflow? And why wouldn't creating a larger opening help in moving the water faster out of the upper level so it wouldn't overflow?

First of all keep in mind that with a waterfall of any shape or size the flow of water over this structure is gravity-fed. With that in mind think of the weir as piping or tubing. All piping/tubing has a maximum gravity fed flow rate. Only so much water will pass through this piping in a given time. The larger the piping, the greater the maximum flow rate. If water is pumped into a pond at a higher flow rate than what the piping (weir) can handle, water will back-up, so to speak, and the water level will rise in the pond. Weir width and depth is very important.

 

[lachancesare]

Thanks all, especially Meyer.
I'll let you know how things work out (with pics)
Mike

 

[Lisak1]

Ah! Precisely the opposite of what I thought! So just reverse everything I said and do that! haha!

Sounds like you have a plan! Good luck. Take lots of pictures - we love to see people work!

 

[Lisak1]

Also I think I had some really good ideas for anyone with the opposite of your problem!

 

[lachancesare]