Idea for Spillway....not sure this can even work... pls help!

[JenH]

If you haven’t seen my other thread.... I’m currently building a new partially above/below ground pond with gravity bog/veggie filter in NW Indiana.

I’m almost to the point of designing how my water will spill back into the pond and I had what is probably a crazy idea that’s probably not possible without causing the bog to overflow over the sides and back, but I was thinking ....instead of your usual weir or spillway, of using 3-4” pvc pipe, spray painted to look like copper pipe (much cheaper alternative to the real stuff) extending out of the bog on one side of the front, over the pond horizontally and then returning back into the pond on the other side. It would only be extending out however far is necessary to have space for the two 90 degree elbows.
I would then drill holes across the entire length of the underside to create that raining/pouring water effect back into the pond.

My bog will be 12” deep with pea gravel and I am using a 4500 gph pump with 1.5” flex tube from pump to bog and 2” pipe inside the bog.

Is it possible to do this or will the flow rate of my water channeling into the pipe cause the bog to back up and overflow over the sides and back? Thanks for your help!!

Here is a diagram of what I mean (sorry, I’m a terrible artist)...

Thanks for your help!!

 

[IPA]

I like it. Maybe You could add an overflow pipe higher just in case it ever gets clogged.
How many gallons is the pond, bog? 4500 gph may turn out to be to much flow. If it is is the pump returnable? If not you can design a diverter if you find it necessary as you wouldn’t just want to simply restrict the flow to much or the pump will have to work too hard and won’t last.

 

[Chucker's 50]

By my calculations using the dimensions from your other post (5'X8'X27") the main body of your
pond holds 660 gallons of water, I believe that a 4500 GPH pump is too much pump.
I have a 2000 gallon pond and a 3100 GPH pump and it does a great job.
I would be inclined to suggest something in the 1000 to 1200 GPH range.

This is just my opinion, not a pump sizing expert by any means.

 

[mrsclem]

It could work with the right flow rate. I see 2 possible problems. #1 weight of pipe and fittings plus flowing water could collapse the setup. #2 Those drilled holes are going to clog, fast. I have 1"pvc pipe as a spray bar over my window box bogs. 1600gph and it clogs every other day

 

[poconojoe]

How about doing the same thing, but instead of using 3/4" pipe, use 1-1/2" PVC pipe. Make sure the spray holes on the bottom are at least 1/4". Then slice the very top of the pipe along it's length to open up the top of the pipe. The top of the pipe will be open along it's length maybe 1/2" wide for overflow in case the bottom holes clog.

The suggestion of an additional emergency overflow pipe depositing into the pond from the bog is a good idea too.

 

[AlyssaFish]

Place mesh grating inside the PVC pipe to prevent anything large from getting to where it might clog the drilled out holes. The mesh might still clog, but it seems like that would be easier to clean out than trying to get into a pipe.

You could also do an overflow system in the bog, leading into an empty chamber where the water would be able to go into the PVC pipe. To get an idea of what I mean, look up overflows in aquariums for installing a sump tank.

So, water flows up into your gravel bog thingy. Then it hits the overflow and starts traveling up, to the surface. Once it reaches the top of the overflow, it spills inside. Then you've got the mesh grating to protect the inside of the pipes from leaves or string algae or whatever.
Place a cover over the overflow so that you can access the mesh easily for cleaning and debris can't fall inside it. You could even place gravel over the cover so that it blends in with the rest of the bog if you wanted to.

With any luck, that should create a system that self-maintains fairly well and is easy to clean when it doesn't. You can always drill in more holes or make the holes larger after if the flow is too fast.

It sounds like it should work to me. That doesn't mean it will, of course. But it sounds like it!

 

[Tula]

Sounds like you've already received good advice, but I'll chime in to say your pump is too powerful for the volume of water to shower out nicely...it just may blow the whole overhead pipe to the sky LOL

With a properly sized pump you could add a diverter and play around with the flow to the overhead bar.

 

[JenH]

Thanks everyone for the advice!! After reading it all..... I’m just gonna stick with an nice easy spillway.

I do have a powerfull pump. It’s the same one actually I had with my old pond.... but even then I had always wished I had a bigger one for a stronger waterfall.

now I am trying to figure out if I should fill the bog with gravel or give it a go empty to try and settle the liner. Gravel comes tomorrow and after that it will be finished!! Yay finally!!

 

[poconojoe]

If your pump seems too powerful, add a "Y" fitting and put a valve on each side. Send one side to the bog and the other to another waterfall or just send it straight into the pond. Then you can adjust each valve to get the flow you want.