Pond design feedback wanted

[Patrick H]

Hi all, I attached a screenshot of the pond I am planning to build. After collecting rocks for almost thirty years I have started digging. It is important for me to build this thing myself. When I went to a local pond store I was very upfront about this, but I explained that in return for their advice I would buy the liner, pump, filters etc. from them. They were not interested. I think that with as much as this area if growing they have plenty of work putting in turn-key ponds at milion dollar houses.
I am an architect and familiar with building things myself. I expect there will be a lot of fine-tuning during the build process, and even after it is finished. I want to avoid making big mistakes that will be very hard to correct after it is build.
The pond I like to build is a whale shaped form, fitting in between existing trees and a patio. To simplify things I was looking at using an Auquascape skimmer and their biofalls. Liner will be 45mil EPDM. I plan to have a shelf pretty much around the perimeter of the pond with flat rocks on the shelf, then up the side to grade and then large flat rocks along most of the perimeter. (In Idaho you can get a BLM permit to collect rocks at certain quarries and I build up quite a collection over 30 years). Below the shelf I was thinking to leave the liner exposed but then put gravel on the bottom. Any comments on this basic plan are welcome.

My first question is at what level should I put the shelf? Right now I was thinking to have the water level about 6" below grade. With this I could use our flood-irrigation ditch (water straight from the Boise River) to fill the pond and keep it topped-off. I want to put the shelf deep enough so the exposed liner below it is less vissible, but shallow enough to use for plants. Is 24" deep good?

Thank you!

 

[tinycat]

My suggestion is to start with a much smaller pond so you can learn the ins and outs of having a pond. Small can be enlarged as time goes by. You can even tie a series of smaller ponds into one big system as you learn how it all works. As for shelf depth, 24" sounds good for plants, perhaps have part of it shallower. Clear water needs lots of plants to use up nutrients, so lots of plants on that shelf, would be good. If this pond springs a leak in the future, consider how much work it will be to remove rock and gravel to get to the area to fix it. And how will you clean the gunk that slowly builds up in the cracks between rocks. Also consider safety while you are in the pond doing maintenance. Will those rocks fall? There are many ways to configure a pond, you can have no rocks or gravel in the bottom, and just decorate the upper areas. You could set rocks on an intermediate shelf, then on a second shelf above that have your plants. You could have gigantic boulders that require heavy equipment to move, or smaller rocks that a human could lift.

Is this going to be a wildlife pond? Fish? Other critters? The amount of biological waste in the pond will influence things big time. if you are bringing in ditch water consider pathogens that water might bring in that in turn could affect the health of any fish. Will overflow wind up reentering a natural waterway and create an ecological invasion of non native plants/animals into the wild? If you start with a smaller pond, you can get a feel for how it all works and have a managable size to work with. If you wind up with lots of problems, it could be you are all on your own to fix it. Start small and learn as you go. watch lots of youtube channels on pond building. Check out Ozponds there. that site has all sorts of good info and will provide insights into how to make things work. Highly suggest watch a lot of videos before you begin. understand how the water chemistry works, how the biological system works, how waste management works in terms of different type pond setups.

 

[Patrick H]

Thanks for the suggestions tinycat. I'll start by answering some of your questions. My main reason for the pond is not for the fish, but I do think we would want some goldfish and frogs. How we would control how many I don't know yet. There is no overflow from our irrigation system back to the river. We have a one way system where the water is pumped up, then gravity flows to irrigate our yards. I have a concrete irrigation box from where I could pump the water into the pond. I do plan to use a small submersible pump to draw water out of the pond to irrigate my vegetable garden. This would then be replenished with cold water. Our river is very clean, people float it all summer long, and I don't recall there ever being a no-swim warning for the river. There are a couple of lakes though that do grow pathogens and people are advised to stay out. This typically happens at the end of the summer once the water warms up. Our river water comes from reservoirs in the mountains that stay cold year round.

There are a couple of reasons for the pond size. First of all: this is probably the only pond I will ever built. I doubt I will still be able to move rocks like I do now in ten years. Also, I was under the impression that a lot of pond water quality issues are caused, or made worse by water temperatures. Even though my pond will be mostly shaded by trees, the sun is very strong here and we do get 100 degree-plus days. I figured that by having more volume of water the pond would stay cooler.

Thanks again, Patrick

 

[sissy]

30 years of collecting just the rocks . WOW Important is to know your worst eather conditions and your best weather conditions . Both hot and cold and what kind of fish ASlso airation and pond heater if you may need one . I knw to keep fish n cooler water here in the summer I had to go deeper . Down to 5ft on one side and going up tp 3 feet on the other end . I still had to provide more shade with the bridge and shade cover and winter seems the fish stay on the deep end of the pond at the bottom . I took the aerator out but left the air hoses in the pond . My first pond was a preformed and then dug out second pond to 15 hundred gallons and then 2 thousand 5 hundred gallons and then just over 5 thousand gallons I wish i had been on this sight and learned how large my 2 koi would get .