First Timer - Bog-waterfall-pond design advice

[drbballwater]

After a few weeks of reading about this stuff I’ve decided to go ahead with a bog-to-waterfall-to-pond design in a spot in the yard that, on the surface, looks intriguing. I have a 1-2ft wife fissure between two massive natural boulder elements with ~3 feet of drop between the top where I would like to put a bog and the bottom planned pond location (see photos).



Today I removed the plants andto get a lay of the land and some pics. My first two points where I’m seeking input:

1) The best way to waterfall/stream/step through the gap. The massive natural boulders would act as the framing boulders I assume. Just not sure how to best get decent liner coverage through there seeing as I won’t have the option of running the liner up and over the sides. Just run it up the sides of the boulders 5-6” from the stream bed and hold in place/conceal with rock? See my diagram of the cross-section through the waterfall/stream.

2) Pond size. Understandably a personal choice but here is the relevant info. The bog can only be ~4 x 4 ft due to the physical constraints of the two boulders, a walking path behind, and the waterfall drop in front. I’m interested in some type of fish with koi being the slight preference. The pond would bite into the prime turf spot in my yard where my little kids play so I don’t want to go too big. I haven’t yet looked into the local bylaws that might limit depth without fencing requirements.

Likely many more questions to come but I just want to make sure it’s even possible in this location. I should note, with two kids under 4 and two businesses to run, realistically I’m looking at a Spring 2021 completion so no big rush. I want to get this right, I think it will look and function great if I can nail it.

 

[addy1]

Welcome to our forum!

That will be so neat!
I would think you can figure out a way to lay a liner in that gap. Using rocks to cover up the liner edge.

Concerning koi, unless you build a pretty decent sized pond, 3000 gallons if not more, the pond won't be big enough for them. They need a lot of filtration a lot of water.

I would suggest shubunkins, called poor mans koi, very pretty colors long fins etc. That is all I have. I have the water room for koi but no desire to mess with them. Shubbies require almost nothing. Mine hardly ever get fed they do well on their own eating what the pond provides. I do have a lot of plants.

 

[mrsclem]

Let me ask this question- When you get heavy rain, does water flow down thru this area? If so, this could be a problem with runoff getting into the pond.

 

[drbballwater]

Welcome to our forum!

That will be so neat!
I would think you can figure out a way to lay a liner in that gap. Using rocks to cover up the liner edge.

Concerning koi, unless you build a pretty decent sized pond, 3000 gallons if not more, the pond won't be big enough for them. They need a lot of filtration a lot of water.

I would suggest shubunkins, called poor mans koi, very pretty colors long fins etc. That is all I have. I have the water room for koi but no desire to mess with them. Shubbies require almost nothing. Mine hardly ever get fed they do well on their own eating what the pond provides. I do have a lot of plants.

Thanks Addy. I do like the shubby idea, I was toying with that already for the reasons you stated. Would allow me to stock a few more per gallon vs koi I assume. Then I could keep the pond 6’ x 10’ -ish. I think I’m sold.

 

[drbballwater]

Let me ask this question- When you get heavy rain, does water flow down thru this area? If so, this could be a problem with runoff getting into the pond.

Aside from the bit of rain that lands on the boulders and trails in no, it’s not a major runoff area. There’s a turf walking path on the top side of that area that has historically been the runoff route as it is parallel with the slope of the mountain I live on, the waterfall gap runs cross-ways to it.

I do wonder about the little bit of runoff that lands on the boulders, how it could sneak behind the liner. I don’t think it would ever be enough to worry about erosion and collapse but I’d like to mitigate against if possible. Not sure if I should try to seal it in some fashion or just live with the bit that would get behind every rainfall.

 

[Mmathis]

Hello and welcome! What a lovely setting!

 

[j.w]

@drbballwater
Looks like a beautiful project! Shubbies are pretty fish

 

[GBBUDD]

I do wonder about the little bit of runoff that lands on the boulders, how it could sneak behind the liner. I don’t think it would ever be enough to worry about erosion and collapse but I’d like to mitigate against if possible

In between ledge in a narrow area as such by the time you fold over the liner and cover it with some rock/ flat ones i would think . it's going to get narrow but it can still be very appealing with some time spent thinking of how it looks naturally and getting creative like maybe some logs placed along holding the liner edge you could always secure the liner to the underbelly of the log then some rocks . or if your unaware they also have what is called rock on a roll they have a type similar to your granite at least it appears to be. My two cents id have the falls come out from under the bush and turned slightly away from the direction of your build so you see it more from the side have it land in a small pool the work its way down you should be able to get at least three or four drops . as to the ledge i would cut into the ledge with a grinder and make the cut 1inch deep buy diamond blades money well spent. Apply A QUALITY CAULKING that will stick to epdm pl-s30 is a polyurethane base but some even use silicone i prefer poly. run a bead of caulk in the cut tuck the liner in and use shims to wedge the liner in tight but not so tight you squeeze out the caulking let it cure then remove the shim wedges and then caulk the top. sealing in the rubber. your lucky your ledge is relatively smooth and is not fractured. Now for the hard part but he absolute crown jewel that drop at the end between those boulders if yo do it right it could be amazing but it's going to take some work. having the water drop in the last section there into the pond its going to splash and ni think thats where rock on a roll maybe handy as if you cut the rock caulk shim the rubber tight remove shims install rock on a roll caulk shim and caulk with a gray caulking then sprinkle dust from the cutting the rock you can make the caulk disappear and if it is sealed the moss will probably grow over it . it could be quite the focal piece for sure. normally i don't advise this but no fractures ,solid rock , killer design yeah i'd have to go for it myself very jealous good luck . I don't know how handy you are but one other thing i would contemplate and i know this is unorthodox is to use two pieces of rubber one for each side of the ledge so you get as straight and no wrinkles into the cut in to the rock . then seam the two in the middle of the stream . the reason i say this is if you end up with multiple folds and try to tuck the rubber in three layers thick it will be a fight to seal it up and it;s going to be a challenge as is . much easier to seam int bottom at least for myself. If you lay out the rubber and you can do so with out folds in the rubber or only one and it's not to bad then good luck.

 

[GBBUDD]

The more i look at it you might get real lucky and have those two pieces be one section of ledge just add water and watch it roll down the hill. caulk any cracks build a falls area . dang that would be sweetttttttttttt. but you'd still have to deal with the top and pond .

 

[drbballwater]

The more i look at it you might get real lucky and have those two pieces be one section of ledge just add water and watch it roll down the hill. caulk any cracks build a falls area . dang that would be sweetttttttttttt. but you'd still have to deal with the top and pond .

Interesting suggestion, woulda never thought to cut into the rock. I think I understand how it would work but check my diagram to confirm. And would the water level then be fine to run above where the liner is set into the rock? Other question is would the Rock on a Roll get placed on top of the liner for a better aesthetic and also get caulked in?

 

[GBBUDD]

Interesting suggestion, woulda never thought to cut into the rock. I think I understand how it would work but check my diagram to confirm. And would the water level then be fine to run above where the liner is set into the rock? Other question is would the Rock on a Roll get placed on top of the liner for a better aesthetic and also get caulked in?

I would not tempt mother nature to test your work I would not put the water level at or above. I would leave in down at 2 inches. It won't be easy figuring exactly where the water levels will be in the streams . At a ponding area much easier. That's where hiding the liner and or rock on a roll come in. Let's ay you are fighting with the liner and or getting it to fold nicely looks ugly cut another trench and put the rock on a roll in its own . Looks better and it could be a doble layer of protection . No matter what rock absorbs water. Now I know some people re saying I'm crazy but it does. So keep that in mind no matter how perfect your work you may alway loose some water to this .
Yes to your drawing. But unlike in the drawing the rubber will not be a nice fit square line you will have folds Wrinkles . Thats where I said I'd think about seaming the bottow and keeping the are you tick into the rock as flat as possible There's a post in the pond construction and equipment at the top on seaming epdm with videos.

 

[GBBUDD]

I would not tempt mother nature to test your work I would not put the water level at or above. I would leave in down at 2 inches. It won't be easy figuring exactly where the water levels will be in the streams . At a ponding area much easier. That's where hiding the liner and or rock on a roll come in. Let's ay you are fighting with the liner and or getting it to fold nicely looks ugly cut another trench and put the rock on a roll in its own . Looks better and it could be a doble layer of protection . No matter what rock absorbs water. Now I know some people re saying I'm crazy but it does. So keep that in mind no matter how perfect your work you may alway loose some water to this .
Yes to your drawing. But unlike in the drawing the rubber will not be a nice fit square line you will have folds Wrinkles . Thats where I said I'd think about seaming the bottow and keeping the are you tick into the rock as flat as possible There's a post in the pond construction and equipment at the top on seaming epdm with videos.

 

[drbballwater]

I would not tempt mother nature to test your work I would not put the water level at or above. I would leave in down at 2 inches. It won't be easy figuring exactly where the water levels will be in the streams . At a ponding area much easier. That's where hiding the liner and or rock on a roll come in. Let's ay you are fighting with the liner and or getting it to fold nicely looks ugly cut another trench and put the rock on a roll in its own . Looks better and it could be a doble layer of protection . No matter what rock absorbs water. Now I know some people re saying I'm crazy but it does. So keep that in mind no matter how perfect your work you may alway loose some water to this .
Yes to your drawing. But unlike in the drawing the rubber will not be a nice fit square line you will have folds Wrinkles . Thats where I said I'd think about seaming the bottow and keeping the are you tick into the rock as flat as possible There's a post in the pond construction and equipment at the top on seaming epdm with videos.

I’m intrigued by the idea. When I get to that point I’ll dry run the concept on some other boulders in the back 40 to see what kind of look I can get with the trenching and caulking technique.

 

[GBBUDD]

Before you go cutting into that area before I narrow and at the narrow I'd check to see if those two exposed ledge are one piece of granite .it may already hold water