Requesting Feedback: Seeking Guidance for Successful First-Time Pond Build

[ChiDIY]

Doesn't look like your going to have all that much hight between the upper pool and the falls I would not rely on overlaping I would seam the two pieces .

Thanks - that makes sense and seems (pun intended) like a good idea.

Here's a cross section drawing of the current configuration of the waterfall.
- purple is waterfall liner
- green is pond liner
- I backfilled dirt behind the spill stones to press the 2 liners together

Is there some way water could get forced up through the 2 liners up under the pool? That wouldn't be good.

I'll look into seaming; doesn't seem too hard

Flattening out the liners/removing folds to make a good connection will probably be the hardest part. Some of those frame stones are so heavy that removing them might not be possible.

 

[GBBUDD]

Yeah according to your drawing you have 4 inches at best of over lap above the water level. That I would consider as bare minimum. All the overlap that is underwater unless seemed means nothing water gets between the liners and will flow to the max water line or higher if it starts to wick

 

[YShahar]

Thanks! This makes a ton of sense. I think my issue is I piled the dirt up on an angle from the stock tank bio filter down to ground level on the left side.

In the pic below:
- The white line is the rough angle of the waterfall mound. Because of this the left side of the pool has no berm and just drops off.
- The orange represents how I think I need to adjust the mound. I think this will allow me to build the pool down into the mound and have a berm on both sides that butt up against the back of the frame rocks on the left & right side of the falls into the pond.

I would even build up beyond the orange line. Instead of a slope, think of your stream as a series of steps, with a wall on either side of each riser. If you picture it that way, it becomes much easier to visualize how to mound up your soil on the sides.

One other trick is to offset your cascades to the right and left of a center line as seen from the viewing area. So for example, the next step up from your main falls might be a cascade facing the viewer, but located to the left of the falls. The one just above that would face the same direction, but would be to the right of the main falls. This zigzag makes for a more interesting, and more realistic, set of cascades than if you just made a curved stream with cascades following the curve. The reason the zigzag is more realistic is that rock usually breaks along more or less straight horizontal lines, so having each cascade face the same way is in keeping with the way a rock hillside would naturally erode.

Also, as @GBBUDD pointed out, you'll want your stream liner to overlap your pond liner with a drop of at least 15 cm or so, to prevent water from working its way up between the liners due to capillary action.

 

[ChiDIY]

Yeah according to your drawing you have 4 inches at best of over lap above the water level. That I would consider as bare minimum. All the overlap that is underwater unless seemed means nothing water gets between the liners and will flow to the max water line or higher if it starts to wick

Ok - I may be ok in that case. I apologize for the confusing not-to-scale drawing; the vertical rise from the waterline to the pool (which is where the pond liner sits) is 7" not 4".

I could increase the vertical rise by increasing the height of the pool & moving the spill stone up. The pond liner has an additional 16" of excess in the pool, and there is 8" between the top of the spill stone & the top of the frame rock.


This pic shows the pond liner in the pool coming out from under the waterfall liner. The back of the frame rocks to the end of the pond liner is ~16".

I could probably raise the spill stone and pool up several inches and it would still look good. There's 8" between the tops of the spill stone and lowest frame rock.

 

[ChiDIY]

Instead of a slope, think of your stream as a series of steps, with a wall on either side of each riser. If you picture it that way, it becomes much easier to visualize how to mound up your soil on the sides.

One other trick is to offset your cascades to the right and left of a center line as seen from the viewing area. So for example, the next step up from your main falls might be a cascade facing the viewer, but located to the left of the falls. The one just above that would face the same direction, but would be to the right of the main falls.

This helps - I think I'll carve out a few steps and experiment a bit.

Also - capillary action - didn't think of that. I might as well raise up the final pool a bit; will make for a more dramatic fall into the pond anyway I suppose.

 

[ChiDIY]

Reached a big milestone this week; filled the pond with water! So nice to have water in the yard instead of a big rock pit.

It's been running since tuesday, the water level is holding, the waterfall isn't losing water, and everything appears to be working as planned

The bio filter is working well; the water turned crystal clear within 12 hours.

I'm a little worried about how the outlet design will handle freezing temps. I used 3" pipe with a bunch of slots cut into the top half with a circular saw (~1/8" wide) which prevents the pea gravel from getting into the waterfall. I don't understand the nature of how running water freezes and I can imagine this design freezing over.

I have several months to think about options. I used a bulkhead with npt/threaded fitting so trying different things will be easy.

Next steps:

• Finish the waterfall
  • fine-tune spillway stones
  • Rock in the top pool & hide outlet pipe
  • Foam
  • Add gravel
• Hide liner
• Finish rocking in/hiding skimmer
• Plants
  • Bog filter
  • In pond
  • Outside pond
• Landscaping / hardscaping
  • Waterfall mound retaining/stones
  • Viewing areas
  • Hide bog filter
• Fish

This is a huge milestone! Its a massive relief that everything is working and so amazing to have a pond in my yard. Thanks to all of you who provided feedback to this thread and helped build up the mass of knowledge contained within this forum

 

[RMaynard]

Looks great!

For the bog outlet, I would replace the end cap with an elbow pointing up, so that the opening of the elbow is above the desired waterline, but below the point where water will start overflowing the bog. That's your last resort, if all the slits get clogged it will have a backup outlet with the full capacity of the pipe.

 

[YShahar]

Reached a big milestone this week; filled the pond with water! So nice to have water in the yard instead of a big rock pit.

It's been running since tuesday, the water level is holding, the waterfall isn't losing water, and everything appears to be working as planned

Looks great! Good feeling isn't it, when it finally starts looking more pond-like. And it will only get better as plants fill in.

 

[EricV]

Especially with an odd-shaped pond (and especially that T you initially showed) I definitely recommend metering the size of your pond rather than guessing/calculating. Orbit makes a cheap hose end meter you can use or you can even go super low cost and time how long it takes to fill a 5 gallon bucket.

Doing this I learned my garden hoses put out about 500 gallons an hour. When I refilled my pond the second time, I for sure used the hoses from the front and back yard!

 

[GBBUDD]

i fear your drain tube from the bog is a ticking time bomb . you don't have a back up and any plants will quickly overwhelm that one lonely pipe. are those cuts for supply to the bog or drain"?

 

[ChiDIY]

i fear your drain tube from the bog is a ticking time bomb . you don't have a back up and any plants will quickly overwhelm that one lonely pipe. are those cuts for supply to the bog or drain"?

I used the same 1/8" wide cuts a little less than half way through the pipe for both the supply and drain.

I agree its a weak point of the design especially with plants & freezing temps. I'm thinking of going with @RMaynard 's suggestion of replacing the end cap with an 45° (or so) degree elbow to create a large upward-facing opening, or just cutting the top 1/3 or so of the back half of the entire pipe to create a large opening which would sit above the pea gravel.

I'm also considering an overflow above this main outlet; like a 2" pipe going directly into the pond rather than through the waterfall. In the case the main outlet becomes blocked the drying up of the waterfall would serve as an alarm.

 

[ChiDIY]

Especially with an odd-shaped pond (and especially that T you initially showed) I definitely recommend metering the size of your pond rather than guessing/calculating. Orbit makes a cheap hose end meter you can use or you can even go super low cost and time how long it takes to fill a 5 gallon bucket.

Doing this I learned my garden hoses put out about 500 gallons an hour. When I refilled my pond the second time, I for sure used the hoses from the front and back yard!

Nice! The pond took between 5 and 6 hours to fill; since its already full I'll time a 5 gal bucket fill for now. My estimate for size is around 3K gallons based on the dimensions but with the multiple shelves & depths, tons of rock, and odd shape calculating with a tape measure definitely isn't very accurate.

 

[GBBUDD]

replacing the end cap with an 45° (or so) degree elbow to create a large upward-facing opening

If I'm reading this right that's not a great idea as the open pipe will have no back pressure as will the pipe buried under the gravel. It may for a short period ofvtime but the second the gravel starts to get pressure due to the gravel sifting out the waste the water will take path of least resistance. '

 

[ChiDIY]

If I'm reading this right that's not a great idea as the open pipe will have no back pressure as will the pipe buried under the gravel. It may for a short period ofvtime but the second the gravel starts to get pressure due to the gravel sifting out the waste the water will take path of least resistance. '

Here's the current design: the water rises out of the pea gravel and flows through the 1/8" slots in the 3" pipe into the waterfall. I took this pic before leveling out the pea gravel; currently the pea gravel is below the slots in the pipe.

Here's a drawing of the open elbow option providing a large outlet if the slots get clogged. The brown is the gravel & blue waterline if the slots aren't clogged and allowing water flow.

The slots in the pipe are all above the gravel line so I don't thin the path through the gravel matters; as long as the water ascends above the pea gravel and the slots aren't blocked it will flow through the outlet. The open elbow option provides a route for the water if the slots do get blocked.

 

[YShahar]

Here's the current design: the water rises out of the pea gravel and flows through the 1/8" slots in the 3" pipe into the waterfall. I took this pic before leveling out the pea gravel; currently the pea gravel is below the slots in the pipe.

Wouldn't it be simpler to make a cut-out in the plastic container? You could then either attach the stream liner to the cut-out in the same way you would attach it to a skimmer box. Or just run the stream liner underneath the container and let water come out of the bog through a long slit or cut-out.