Pondless waterfall construction

[Drz]

Hi all. I was hoping to get some advice on my waterfall construction in my backyard. I'm going the DIY route, but I'm not especially handy and this is on the upper end of projects I can handle. I just enjoy doing things on my own.

Here are some pics of the area I'm building the waterfall, and some work already done:


View of backyard. Waterfall will be at left.


Waterfall location. Starts near the iron fence, spills to the bottom. The bottom and middle are flat, while the top rises about 2 feet over an 11' distance.


There will be no koi or fish, and I'd like to go pondless, hence the small 7' x 3' size. Since this picture I've dug the a hold a little over 2 feet deep.


I'd like to split the top tier into three individual streams.


The top (waterfall source).


I've also created this overhead diagram in Paint of what I'm going for:




I have a buttload of questions at this point... answers or any other advice would most definitely be appreciated.

1. What size pump do I need? It would run about 40 feet, including about 10 feet of total rise (somewhere on the internets I came across this wording: "The general rule on pond pumps is 10 feet of horizontal length reduces water flow as much a 1 foot of height from the pump does."). I'd prefer a medium-to-fast flow.

2. What tube type/diameter do I need to bring the water from the pump to the source?

3. Would there be a problem with splitting the pipe three ways so the water would flow into three separate streams (as seen in the diagram)?

4. How deep does my basin need to be if I use water matrix blocks?

5. Are Water matrix blocks really needed, or would milk crates or plastic pipes be enough?

6. I read some of the horror stories on here of people who didn't reinforce their sides. Would that be necessary in the Texas limestone, for a pondless construction? My gut says no (it's solid rock under the ground here, I had to rent a jackhammer to dig out what I've dug so far) but I wanted to see if anyone's had a problem.

Thank you,
Drz

[fairlady]

Your project looks interesting...Please post pictures as you progress.
I'm sure the construction guru's will be able to answer your questions when they pop on.
Good luck.............

[mbrian1226]

Hi all. I was hoping to get some advice on my waterfall construction in my backyard. I'm going the DIY route, but I'm not especially handy and this is on the upper end of projects I can handle. I just enjoy doing things on my own.

1. What size pump do I need? It would run about 40 feet, including about 10 feet of total rise (somewhere on the internets I came across this wording: "The general rule on pond pumps is 10 feet of horizontal length reduces water flow as much a 1 foot of height from the pump does."). I'd prefer a medium-to-fast flow.

You will want 100-200gph per inch wide of stream/waterfall. 100gph for a nice flow and 200gph or more for niagra falls. With a 5.5' wide waterfall that comes to 6600gph using the 100gph per inch wide rule. At that kind of flow I would go with 3" pipe. With a 10' rise and 40' run you are going to have around 15' of total head. You will need a pump producing 6600gph at 15 feet of head minimum. Don't forget to calculate your fittings into the total head.

2. What tube type/diameter do I need to bring the water from the pump to the source?

I would go with 3" pipe.

3. Would there be a problem with splitting the pipe three ways so the water would flow into three separate streams (as seen in the diagram)?

I don't see why not. Build yourself a manifold at the top with three 2" single union ball valves to adjust the flow into each stream.

4. How deep does my basin need to be if I use water matrix blocks?

I would think the reservoir/ basin would need to be 1 1/2-2 times the volume of water the stream will hold. I would rather have too big of reservoir than too small.

5. Are Water matrix blocks really needed, or would milk crates or plastic pipes be enough?

I would use the water matrix blocks. Depending on the type of milk crate they might not be strong enough.

6. I read some of the horror stories on here of people who didn't reinforce their sides. Would that be necessary in the Texas limestone, for a pondless construction? My gut says no (it's solid rock under the ground here, I had to rent a jackhammer to dig out what I've dug so far) but I wanted to see if anyone's had a problem.

Sounds like your ground is hard enough that you shouldn't have to worry about the sides giving away and caving in. If you lived in an area where it rains a lot with soft soil then I would say to reinforce the sides.

Thank you,
Drz

[birdman]

Agree with what Brian said but I don't know what Water matrix blocks are. I would build the pond with blocks to match your retaining wall.

[minterca]

I agree with Brian. I have a pondles in my front flower beds.
The basin needs to hold all of the water that id in the falls.
Also consider the splash from the final fall.
That large of a pump, I would consider an external pump.

[wayne r]

As far as pump size goes;
and the flow you want at a 10 ft rise, bigger is better.
I would not be thinking about any less then 6000 gal. per hr. pump with 3" feeder line.

Thats my guess from trial and error.

[ceejay4801]

agree with the above, but just want to remind you that when shut down that all the water has to go somewhere and if you have only one basin at the bottom it has to hold all the water for the falls. You might want to consider two basins one at the first drop smaller than the bottom one ie a 5 x 6 x 5( 1125 gal) then flowing over to the bottom basin with dimensions of (10 x 10 x 6 ) for 4500 gal giving you 5625 gal in basins. More will be in the piping, but not really a significant amount. This could allow you to pump from both basins with two seperate pumps. might give you an easier time than fighting 10 to 15 ft of head.

[WAC]

1. What size pump do I need? It would run about 40 feet, including about 10 feet of total rise (somewhere on the internets I came across this wording: "The general rule on pond pumps is 10 feet of horizontal length reduces water flow as much a 1 foot of height from the pump does."). I'd prefer a medium-to-fast flow.

Pump flow will be 100% dependent on the style of waterfall you want coming down the tiers but a bare minimum recommendation is 100gph ... 150gph avg ... 200gph high. So if at any given point you're expecting a 5' wide solid sheet of water, then you're immediately looking at 9000 to 12000 & that's AFTER you've overcome all the friction loss. You're right, generally, 10' of horizontal run = 1' of vertical rise. Keep in mind each & every 90deg elbow will slap on another 1' of rise. Add those to the actual 10' of vertical rise. With such flows, oftentimes 2 pumps will be more energy efficient than 1 large pump. Another option is to consider a variable speed pump ... reason for this is that projects start w/lofty intentions, then the sound of water & resonance in the backyard can actually get too distracting (sometimes even obnoxious) for you or your neighbors. It's fun to have a variable speed pump so you can dial it down for a calm evening or dial it up for a big hoopla-of-a-dinner party!

2. What tube type/diameter do I need to bring the water from the pump to the source?

Once the pump(s) is determined, the pipe/tubing size can be ascertained.

• 1.5" will allow a max flow of 3000gph
• 2" will allow a max flow of 4800gph
• 3" will allow a max flow of 9000gph
• 4" will allow a max flow of 12000gph

Sometimes it costs LESS $ using qty (3) 2" pipes to get you to 14000+ gph (in terms of pipe costs as well as escalated pricing on fitting costs!) the price of fittings jump DRAMATICALLY when you go from 2" to 3" or 4"!

3. Would there be a problem with splitting the pipe three ways so the water would flow into three separate streams (as seen in the diagram)?

No not at all ... ball valve controls needed for all 3 but that's it. Limit the amount of 90deg elbows ... if you want to (or need to) reduce the amount of friction loss, use two 45deg elbows or long sweep elbows versus your standard 90deg elbow.

4. How deep does my basin need to be?

My recommendation for all pondless projects is that the basin should comfortably hold 3x the volume of water of everything up stream! This includes the volume of water in your pipe -- even if you use a check valve assembly.

5. Are Water matrix blocks really needed, or would milk crates or plastic pipes be enough?

Personally, I say yes. Although all plastics can crack, there's two MAJOR manufacturers of matrix-style boxes & both are tested w/enormous compaction strength. The units are carried over from industrial drainage & water applications & are often used underneath drives & parking applications. The LAX airport uses them over where utility vehicles drive. The danger in milk crates is the grade of plastic degrades quickly & can crack -- major child/adult/pet safety issue if people walk around the basin that has milk crates w/hundreds of pounds of river rocks & cobbles over the top.

An alternative is to fill the entire basin w/rocks & gravel but that alone is a back breaking NIGHTMARE! 1cu foot of river rock holds approximately 2.2gal of water ... whereas 1cu foot of matrix blocks holds 7.4gal. This means using a matrix you can get away w/a smaller basin foot-print.

Also a lot less prone for clogging over time.

6. I read some of the horror stories on here of people who didn't reinforce their sides. Would that be necessary in the Texas limestone, for a pondless construction? My gut says no (it's solid rock under the ground here, I had to rent a jackhammer to dig out what I've dug so far) but I wanted to see if anyone's had a problem.

Doesn't sound like reinforcing will be an issue considering #1, the nature of your soil & #2, the void will be filled w/matrix blocks w/ a top dressing layer of river rocks & cobbles?

I hope this helps a bit w/your project!

[Drz]

Wow! Post a question, go to sleep, wake up, and answers are ready and waiting!

Thank you all, I really appreciate this. I'll post pictures as I progress. I still need to dig out more of the basin so that'll be slow going for awhile, but things should pick up once that's done.

[Drz]

Thanks again everyone... all your answers above helped more than you can possibly know.

Progress has been steady; I've dug a basin that I think will be big enough, but we'll see. I'm going to order the pump, tubes, and liner and give things a test run before I do anything permanent. I'll update this thread with pictures when I have something more exciting than just a bigger hole.

I have a couple questions on what to order:

1. Based on some responses above, it looks like standard PVC is the best option if I want to save some $$? I was looking at some flexible PVC online and saw the 3" x 50' is about $260... I don't know what the price'll be down at Lowes, but assuming it's cheaper, does it matter if I go flexible or non-flexible? If I went non-flex I'd avoid 90 degree turns as mentioned by WAC above.

2. Does anyone know a good place to buy a high-powered variable speed pump, online or otherwise? I'd probably typically run it at 6,000 gph or so, so I'd like that to be part of the variable range.

[Drz]

I have a couple questions on what to order:

1. Based on some responses above, it looks like standard PVC is the best option if I want to save some $$? I was looking at some flexible PVC online and saw the 3" x 50' is about $260... I don't know what the price'll be down at Lowes, but assuming it's cheaper, does it matter if I go flexible or non-flexible? If I went non-flex I'd avoid 90 degree turns as mentioned by WAC above.

2. Does anyone know a good place to buy a high-powered variable speed pump, online or otherwise? I'd probably typically run it at 6,000 gph or so, so I'd like that to be part of the variable range.

[ceejay4801]

partial answer to your questions. Standard pvc will work and be much cheaper if you go with a box store. I don't see why flex is any better than pvc. Don't have to avoid 90 deg but will reduce head can use sweeps instead and have less head with these. You will need check valves to help out and not have all the water flow back if you shut down the pumps. Standard pvc will be smooth on the inside not all flex is.

Others will chime in on the pump(s).... not sure if you should go variable or use multiple pumps to achieve higher flow... I think that the latter would be better also have some flow if pump goes out. More plumbing, but not very costly just more plumbing than with one pump....IMO I see two one smaller pump say 5500 gph and then a larger one in the bottom say 8500 gph not sure of the heights so the head will need to be addressed to see actual flow...... I think I remember something along the lines of 10 k of water so... with that in mind I don't think I am out of line with these producing enough flow. Also no mention of waterfall sizes so this will also play a role in pump size need about 100 gal per inch of water for one inch of waterfall..

Charlie

[Drz]

I've gotten to the point where my next step is to buy a pump and plumbing, and out of laziness and cheapness I've been putting it off. But now is the time...

My specs:

Total head = 40' horizontal + 10' vertical + 4' due to turns/friction loss = 18 feet of head

Gallons per hour = 150 gph per inch @ 4.25 feet width of waterfall = 7650 gallons per hour

Based on the above, I need a pump that can produce roughly 7,650 gallons per hour at 18' of head. Can anyone comment on whether the pump below would make sense? It's a submersible pump that I'm hoping would produce an average flow of water.

I have almost zero plumbing experience, so a particularly dumb question I have is if there'll be a problem using 3" pipes with this system.

http://cgi.ebay.com/NEW-MATALA-GEYSE...item3a4e7d0049

[birdman]

My gosh you will have to rob a bank to be able to run that thing. External pumps are so much more efficient than submersible pumps, and usually cost a whole lot less to boot. There are several good pumps out there that would suit your needs. An why shop e-bay, buy from a Koiphen Dealer that supports this site and will be there for you when you need help. There are several good dealers here with every brand pump made.
I have a couple choices I sell that would fit your needs at half the cost and half the opperating expense. PM me if interested.

[Drz]

PM me if interested.

PM sent.

[birdman]

PM sent.

Got it.

[WAC]

See responses below in red.

I've gotten to the point where my next step is to buy a pump and plumbing, and out of laziness and cheapness I've been putting it off. But now is the time...

In your temperate region, rigid PVC (sched 40) is fine. The differences between rigid vs. flex is more a factor on durability & cracking w/flex having greater tolerance to cracking (i.e. accidental shovel, etc.)

My specs:

Total head = 40' horizontal + 10' vertical + 4' due to turns/friction loss = 18 feet of head

Gallons per hour = 150 gph per inch @ 4.25 feet width of waterfall = 7650 gallons per hour

Based on the above, I need a pump that can produce roughly 7,650 gallons per hour at 18' of head.

Below, I've attached a picture for a quick comparison ... I based it off of 15' of head for consistency of all pumps shown.

Can anyone comment on whether the pump below would make sense? It's a submersible pump that I'm hoping would produce an average flow of water.

http://cgi.ebay.com/NEW-MATALA-GEYSE...item3a4e7d0049

Technically no, @ 18' it's just barely over 7100gph range -- in your application, you'd want more (esp. due to unforeseen head loss)

I have almost zero plumbing experience, so a particularly dumb question I have is if there'll be a problem using 3" pipes with this system.

No problem w/3" pipe. In fact would be the main option though not the only option. It can also be manifolded from a short run of 3" & wye'd to two 2" pipes. In some applications, having multiple waterfalls lend well to having multiple "injection points" ... meaning not 100% of the required flow has to make it to the apex ...

The benefits of a pond-less or pond-free waterfall is that it is not sustaining life & is purely aesthetic (both visual & audio). One concept to minimize the potential build-up of string-algae in a pond-less/pond-free system is to turn it off when not necessary.

Based on the lower elevation of your house, & massive drop over 3-steps, & decent flow of water, you may find the resonance of water sound potentially irritating or overwhelming (over time). But I digress ...

In a pond-less/pond-free waterscape ... do you really need it ON when you're at work from 9-5 or after 2am?!?!?

As for your pump selection, submersible versus external -- you should evaluate a few factors:

• submersible (out-of-sight & underwater) ... meaning no noise
• external (needs to be hidden or covered) ... pump noise/vibration

Other factors to evaluate is how your bottom basin (reservoir) will be created to minimize maintenance & allow cleaning w/o shovelling out tons of river rock.

[WAC]

Here's a quick video demonstrating some of the components mentioned in previous threads.

http://www.youtube.com/watch?v=DWJ3pwNfno8

[Drz]

Thank you both for the advice!

I went ahead purchased the pump and some supplies through birdman. We had a good phone conversation and he talked me through how some of the plumbing works and other advice. Again, thanks to all, and I'll keep this thread updated with pictures once I make some visual progress.

[Drz]

I finally got around to unpacking my supplies and getting work started again this weekend. So far, things are looking good; I dug some trenches for the PVC pipe (standard, non-flex) and have a plan, it's just a matter of putting it all together. I'll have pics with the next update.

I have a few more questions before I proceed:

1. When I split the PVC three ways at the top using three 2" single union ball valves, I want to use a standard cross fitting, correct? ...attach the cross, put the ball valves right on them, and voila, 3-way split?

2. The bottom drain is 4", but I'm use 3" pipe. Just use a bushing (?) for that? I think that's what it was called at Lowes... just a thing that basically instantly changed the pipe diameter from 4" to 3".

3. Any recommendations on how you guys house your external pumps? I was going to use a utility box and dig it in the ground, but they didn't have any large enough at Lowes (I need roughly 1' x 2.5' by 2' deep).