Pondless Waterfall Build Questions

[msr0459]

Does anyone know approximately how heavy a 10 x 25 roll of 45 mil liner is? It'll be just me, my 14 year old son, and wife moving these rolls once delivered.

 

[combatwombat]

45 mil EPDM weighs about 0.33 lbs / sf. So about 83 lbs. Easily moved in a roll by 2 people. Once spread out, easily moved by yourself.

 

[msr0459]

Spent today digging out more, and planning the water path. The very top dug out area is for the spillway. The white W's are pooling areas, the X is the flat top waterfall rocks. Because of the steep hill, I'll have to come off the main spillway for the 2nd stream. Does anyone think I'll need a 2nd pump for it?

I've also added basically a "trickle" coming off that center pool,.. just thought It'd look like something I've seen in the mountains.

The horizontal white line at the bottom is approximately where the outer edge of basin will be.

Any additional questions and/or advice are more than welcomed.

Marc

 

[combatwombat]

Assuming you get a pump that will flow enough GPH, I can’t see why you would need a second pump.

 

[GBBUDD]

If your design is as drawn with two separate finishing points. Like the last picture your going to have a bit of a battle. The branch where the water goes down a small meandering stream . What is going to make sure too much water doesn't go down the stream. It will be impossible to regulate that unless the termination / end of the stream is the same as the other.

In the attached both pumps work off the same area coming from the negative edge. It drops into a pool with a over flow to the cistern. The cistern pump is small 500 to 800 gallons per hour. The other is to the main pump a 2 inch line. So as it draws water from the little pooling area it pulls the max it can and the ballance is from the second pump that overwhelms the little pool creating the small overflow.

The difference is my branch off is a overflow the water is drawn where the branch splits off.

Trying to have the water go past the little pool in two directions in the correct gph is impossible imo

 

[msr0459]

Just making sure we're on the same page. The circle is where the meandering stream starts. I was planning on making the path narrow, like around 6" or so,..then choke it off with rocks where it begins, so only the amount of water I want makes it through. Then it, and the other smaller stream will both hit the flat top, waterfall rock at the same time, then on to the basin. Why won't that work?

 

[msr0459]

Assuming you get a pump that will flow enough GPH, I can’t see why you would need a second pump.

That's what I was thinking, but one of the websites I was speaking with (that sells materials) mentioned I need to be sure I don't get a pump with TOO much gph, or it could drain the basin by forcing more water uphill than the "water in motion" could handle. So now it seems I can't get concise info on exactly which pump will do the job. Is there a different formula for multiple streams?

 

[msr0459]

It will be impossible to regulate that unless the termination / end of the stream is the same as the other.

I'm confused as to "end of stream is the same as the other" part. The end of the meander stream? Which "other" are you referring to?

 

[combatwombat]

That's what I was thinking, but one of the websites I was speaking with (that sells materials) mentioned I need to be sure I don't get a pump with TOO much gph, or it could drain the basin by forcing more water uphill than the "water in motion" could handle. So now it seems I can't get concise info on exactly which pump will do the job. Is there a different formula for multiple streams?

Where would the second pump draw from?

 

[RMaynard]

I think the 2 stream plan would work, so long as the smaller stream had the lower overflow, but the ability to be blocked as much as necessary to force most of the water over the slightly higher main stream waterfall. They both end up in the same pooling area before going over the waterfall, so seems ok to me.

I think the "too much pump" problem is that in a pondless waterfall, there is a limited amount of water in the basin. If your pump is too strong and your stream too long, you'll have all that water in motion up on the hill and none left in the basin. Obviously you don't want to go too oversized as that costs money and watts, but you can deal with excess flow by throttling the output side with a ball valve, and/or teeing off some of the outflow so it doesn't go all the way up the hill... Maybe a separate fountain feature that disguises the basin?

 

[msr0459]

Where would the second pump draw from?

From the same basin, but the guy said it would be a smaller, less powerful pump. Said they could do a separate Lazer print build of what they call "matrixblox", same as aquablocks.. to sit the smaller pump in, so I wouldn't need a 2nd vault. Sounds feasible I guess,..but certainly more money and I'm just not sure it's necessary. He's a very nice and knowledgeable guy it seems, when I start getting deeper into the science/planning.. he says they can't also be a consultant company, and I should hire one. I simply cannot afford that. So..?

 

[msr0459]

but you can deal with excess flow by throttling the output side with a ball valve, and/or teeing off some of the outflow so it doesn't go all the way up the hill...

I was considering using a Y connector at the top spillway, and throttling down pressure going to the 2nd stream (the one illustrated that starts at the spillway and goes around the tree. Is that similar to what you were describing?

 

[Lisak1]

Ball valves on a wye is the way to go in my opinion - one pump split into two lines. You'll find that you can adjust the flow infinitely better than trying to work with two pumps. I can "math" all day long, but once you're dealing with real rocks, water, slope, etc the ability to fine tune the flow is what will make things really work well.

Choose your ball valves wisely - don't go cheap on those, as they will be impossible to use. Also - vaseline is your friend.

 

[RMaynard]

I was considering using a Y connector at the top spillway, and throttling down pressure going to the 2nd stream (the one illustrated that starts at the spillway and goes around the tree. Is that similar to what you were describing?

I think that means you'd still be sending all the water all the way up the hill, so it wouldn't help with the "too much water in motion" problem, I don't think. But you could tee it off and have that smaller stream begin just behind the tree instead of the top of the hill, reducing the length of the stream and thus the amount of water in motion.

 

[msr0459]

But you could tee it off and have that smaller stream begin just behind the tree instead of the top of the hill, reducing the length of the stream and thus the amount of water in motion.

But where would I be "teeing it off"? From the pump end, as opposed to up at the spillway?

I mean, not a bad idea to it start the 2nd stream closer to the tree,.. but I also kinda like the idea of having the visual of more water leaving the top of the hill.