In over my head, building a huge waterfall. Need pointers.

[Beercan31]

@Beercan31 thanks for the tips. I have a pump and I think 50' of 3' piping. The total height I have to hit is about 16'. Will this do it? Or am I missing something here?
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First things first. That is a very nice pump.

Secondly with out getting into exact product, types of fitting, type of pipe and working with an average calculation you have the potential of a flow loss of 25-30 gph. you will hardly notice it. but like stated earlier your asking 1 pump to lift a water column 16/17 feet through a 3"x50' hose, that's a hell-of-a load don't be shocked to see your electric jump significantly because the pump is working a little harder.


In your build process just give your self the option to do a 2 pump lift at a later date if need be.

 

[combatwombat]

you have the potential of a flow loss of 25-30 gph.

How did you arrive at that number? You mean that you think the pump will do 12470 gph at that head pressure? That with 16' of static head and 50' of pipe that you'll only lose 30 gph off the pump's max flow? I doubt it will even do that wide open with no head at all as most pond pump manufacturers are big fibbers.

that's a hell-of-a load don't be shocked to see your electric jump significantly because the pump is working a little harder.

It'll actually be working less hard. The more head you throw at a pump, the less current it will draw. That's one of the funny things about centrifugal pumps. Not that it's an energy saving practice. You lose more flow than you do current, so the pump becomes less efficient even as it draws less power.

In your build process just give your self the option to do a 2 pump lift at a later date if need be

I think this is the best route. You can even put two identical pumps in series, which will achieve roughly 2x the head capacity (more like 1.75 in real life).

 

[cas]

@cas can you help me understand (if you even had to worry about it) how you would calculate the water in motion for your falls: https://www.gardenpondforum.com/showcase/cass-pond.44/ ?

A couple of people are worried that my 8k gph is gonna feel like a trickle. Basically, I will have like 6-8 falls just like yours all stacked in a winding falls. so I am trying to figure out my water in transit. TIA

Currently I have a Laguna 4200 pump.

This is the information I used when determining the size of pump I needed:

1. Ideally, you want to turn over the volume of the pond 1 - 2 times per hour. My pond is about 800-1000 gallons, which means I needed a 1,000 – 2,000 GPH pump, but that does not include the head pressure, or the width of the falls, which increases the GPH that is needed.

2. Determine the Dynamic head pressure (lift)
height of waterfall (my waterfall is about 3 feet high)
+ (length from pump to falls / 10) (my pump is about 20 feet from the falls, divided by 10)
+ (# of 90 degree bends / 2) (I have one 90 degree bend)
+ (# adapters, joints / 4 ) (I have two)
= head

So for my pond:
3 feet + (20 feet / 10) + (1 / 2) + (2 / 4) = head
3 + 2 + ½ + ½ = 6 head pressure

3. Determine Gallons per hour to support waterfall width
(water fall spillway x 125) (my waterfall is 23” wide)
+ (gallons in pond x 1 times per hour) (my pond is 800-1000 gallons)
= pump Gallons Per Hour

So for my pond:
(23 inches x 125) + (800 x 1) = 3675 GPH (to circulate water 1 time per hour)

4. Then I looked at how the pump was rated at a head pressure of 6. For the Laguna 4200:

• Flow Rate @ 3' - 3296 GPH
• Flow Rate @ 6' - 2853 GPH
• Flow Rate @ 9' - 2092 GPH
• Flow Rate @ 12' - 1395 GPH
• Flow Rate @ 14' - 760 GPH

You can see I am only getting 2853 GPH, even though the Laguna pump is rated at 4200 GPH.

I hope this helps.

 

[GBBUDD]

How did you arrive at that number? You mean that you think the pump will do 12470 gph at that head pressure? That with 16' of static head and 50' of pipe that you'll only lose 30 gph off the pump's max flow? I doubt it will even do that wide open with no head at all as most pond pump manufacturers are big fibbers.

Agreed . your going to loose Thousands of gph due to head pressures. A 3 inch hose full of water hold 3 pounds per foot x 50 =180
17 feet of head in height alone plus fittings call 25 feet or 75
75 +180 is a constant 255 pounds of water pushing up hill. That's why the pumps numbers drop so drastically the higher you go the more fricken that's created.

You have the liner on the hill do a test

 

[GBBUDD]

I guess my phone is a smart phone it chose fricken over correct spelling for friction

 

[Tjsherrill]

Ok, spent my lunch using tracing paper to outline closer to what I am trying to achieve.

The first is current status of the project. The "wier"s if you could even call them that are very wide 8'+ and 4-5' drops. This would take a MASSIVE pump system and I don't want 8' sheets of water.

Image 2 is more what I am going for. I laid the tracing paper on the above image with a light board and mapped it out. AND YES I AM A BAD ARTIST. Narrower falls and more of them. This is why I was referencing @cas. My goal is 8-12 falls that are 8" to 2' wide depending on location, rocks, and positioning. There may be a few other small trickles here and there.

In order to achieve this, I got ~14 more rocks that are larger than anything else I have so far. New rocks are 1-2 tons each. I rented a Kubota KX080-4 which can handle rocks that weight (I have used one of these quite a bit).

I am going to pull the reservoir into the yard by about 4' and remove a bunch of dirt up top in order to make it have more depth.

My plan is to remove it all (yep all of it lots of curse words). Then move the reservoir into the yard 3-4', then start placing rocks, pull the liner over, backfill and work my way up and back like all those aquascape guys do.

Does this plan make a little more sense? It seems like my pump can handle this load. But after talking it out. maybe my reservoir should go up to like 500gal from 370?


Thoughts?

 

[Lisak1]

I won't even attempt the pump math, but I will say that you can never have TOO MUCH reservoir. Build the biggest you can sensibly accommodate. You'll spend less time topping it off that way.

 

[cas]

I think your proposed water fall image is great!

 

[combatwombat]

Drawing looks great! This is a much better plan than where you started. Good call on the outcropping boulders, too. Looks weird if all the rocks are only inside the liner.

 

[GBBUDD]

The liner being over sized is exactly what you want for now. it allows creativity and freedom to place boulders as what looks good not because its within containment. it's actually easy to make your boulders look more 4 to 5 feet tall when they are only 3 . if you placed a three foot boulder out away from the drop of a falls by 2 feet or so fill the area behind that boulder with smaller boulders or gravel but stop say 6 inches before that backfill reaches the top of the lower boulder and place the character stone in the pocket of gravel elevating it to where it now looks like a smaller boulder is in front of it and not one rock stacked on top of another.

Like cw said all the rocks in a row all within a straight liner like a liners restriction looks very man made and not warm . turning one long rock out away from the falls or that simply cuts off the flow of the falls and creates the heavy flow to the other side will look natural

 

[Tjsherrill]

Drawing looks great! This is a much better plan than where you started. Good call on the outcropping boulders, too. Looks weird if all the rocks are only inside the liner.

Thanks. Ya I want to create some wing walls-ish to help it feel natural.

 

[Tjsherrill]

@GBBUDD I totally agree... The rocks I get delivered next Friday at ~4' tall so I'll be able to create a few taller drops while using smaller rocks near them to keep it from being a straight line.

Based on this does my pump seem more in line with what I will need?

@combatwombat based on your notes about gph for width of falls. It seems like at a given level (roughly laid out) I should have less than 50" of falls. Which I think is fine. if there is 1-3 falls per "level" that nets out to some great falls.

I am going to track down a few more aquablox to increase my reservoir size as much as my wife will let me...

Please poke holes in the plan if you see any.

 

[GBBUDD]

to wide is impossible that makes things so much easier . instead off thinking waterfall think ponds/ pools right where you have your arrows i would look to make those pools . very wide and somewhat long . like a pond have the shelves on the sides . this will hide the liner as well as contain any plash. as well as limit the water in motion. then build upward from there

 

[GBBUDD]

heres 12000 gph granted its just pouring out no real structure but it should give you what your looking at AT ZERO HEAD https://www.gardenpondforum.com/threads/going-for-it-phase-one-12-000-gallon-pond.22563/page-12

 

[Lisak1]

I'm excited to see how this turns out! Unlike many people, you took the critique offered and used it to your advantage - that's a great quality to have. You'll end up with a project you'll enjoy and be proud of for years to come!

As for extending the reservoir - remember that what's underground can look different from what's above ground. You can encase your aquablox in liner and put dirt over the top for planting or grass or mulch for a path. You can control how much of the "pondless" part is exposed.