Is a pond viable in a very dry area where it only rains during summer?

Hi everyone, Alfonso here!

I live in a dry part of northern Argentina where we have about 9 dry months and it only rains a bit during 3 months of the year. We have a dry climate, very strong UV index (8-9) and a high altitude (2400m/7850ft). I don't have a proper well (saving for one but they are very expensive) so I have to be careful how much water I use because there is no city water.

I want a pond or a pool of sorts to be able to cool off but I don't know if it would be viable  with so little rain? Has anyone here built a pond in an arid area? How do you prevent water evaporation? How do you prevent mosquitoes from breeding in it and snakes from nesting near it?

Much depends upon your expectations.  You never say how much rain you actually get.

I live in a area that gets 46 inches of rain a year. I have a pond that i estimate to be about 1.5 acres and 20 ft deep.  In summers with low rainfall  the surface has dropped 4 to 6 ft due to evaporation.

Based on the above, I doubt if a pond will be your solution, but it may be part of the solution. I am working off the assumption that some water is better than none.

As for reducing your evaporation, reduce the surface area and increase the depth.  Some kind of covering might help.

Years ago I saw a system set up on a steep slope where there was a pond built into a hill side ( mountain side) to take advantage of the runoff from the slope.   The pond had an 8 inch spillway pipe that emptied into a covered above ground swimming pool.

A lot also depends on the type of soil you have.

Is your soil mostly clay?

Where I live ponds will not stay full unless there is a pond liner.

I have an empty pond as the water just drains out after a rain.  My theory is that the soil is rocky and the rock allows the water to drain out.

We tried adding bentonite clay though this did not work for us.

To fill a pond I have heard of folks bringing in water to fill it rather than wait on rain.

Other folks might create a pond where there is rainwater rushing across the property.

You or others might find this of interest:

At the high point of the property, water is rushing in whenever it rains. This water is cutting a deep channel through the property. The crew decides to capture this water and use it to create an oasis!

https://permies.com/wiki/148356/Ponds-movie-World-Domination-Gardening

Ponds are great! But you'll need shading windblocking trees. Mosquitos are inévitable but you can go out to other ponds and bring mosquito eaters over. And plants. Bats eat tons. It's always complicated to get a balanced system going.
When i came to this house i needed a mosquitonet. There was no pond. Now the system's balanced with all the biodiversity i could get for cheap and a smallish pond with liner(4000 litre) and i sleep with open window.
We have no poisonous snakes, so that's tricky to say something sensible about for me. They're nice snail eaters here that are afraid!
Frogs can be horribly noisy. I put fish in but fish that don't eat all the plants but female frogs just don't lay eggs. Just some older boys come in my pond to chill.
I never fed the fish, water's clear as can be. House gutter run off goed into 1000 litre tank, overflow into the pond. I feed the pond over dry period with the 1000 litre.
The bigger the pond, the bigger the problems, start small! Also not such a drama if it's just no good idea or possible where you are. But it is if you got a lot of money invested.

Even if the pond dries up completely for 9 months of the year, it will put water into the ground when available. Then it will slowly seep in for some time rather than immediately running away.

Yes.

John F Dean wrote:Much depends upon your expectations.  You never say how much rain you actually get.

I live in a area that gets 46 inches of rain a year. I have a pond that i estimate to be about 1.5 acres and 20 ft deep.  In summers with low rainfall  the surface has dropped 4 to 6 ft due to evaporation.

Based on the above, I doubt if a pond will be your solution, but it may be part of the solution. I am working off the assumption that some water is better than none.

As for reducing your evaporation, reduce the surface area and increase the depth.  Some kind of covering might help.

Years ago I saw a system set up on a steep slope where there was a pond built into a hill side ( mountain side) to take advantage of the runoff from the slope.   The pond had an 8 inch spillway pipe that emptied into a covered above ground swimming pool.

My understanding is that we get about 1478mm of rain, only during December, January and February. Sometimes it rains in November and March.

Anne Miller wrote:A lot also depends on the type of soil you have.

Is your soil mostly clay?

Where I live ponds will not stay full unless there is a pond liner.

I have an empty pond as the water just drains out after a rain.  My theory is that the soil is rocky and the rock allows the water to drain out.

We tried adding bentonite clay though this did not work for us.

To fill a pond I have heard of folks bringing in water to fill it rather than wait on rain.

Other folks might create a pond where there is rainwater rushing across the property.

You or others might find this of interest:

At the high point of the property, water is rushing in whenever it rains. This water is cutting a deep channel through the property. The crew decides to capture this water and use it to create an oasis!

https://permies.com/wiki/148356/Ponds-movie-World-Domination-Gardening

The soil is sandy in texture when disturbed and spongey and muddy when wet. From what I've been told it's Andisol ground. If you dig a hole 50cm deep you will find many stones which grow increasingly bigger as you get deeper up to 1 meter (not sure what there is deeper than that as we haven't dug deeper yet)

I am dividing 1478mm by 25mm and getting  59 inches of rain.  That is quite a lot in my world.  I suspect our numbers are off somewhere.

If that amount is correct, and the problem is the rain is seasonal, then a well designed pond should help a great deal. I would think about adding a cistern for drinking water in addition.

John F Dean wrote:I am dividing 1478mm by 25mm and getting  59 inches of rain.  That is quite a lot in my world.  I suspect our numbers are off somewhere.

If that amount is correct, and the problem is the rain is seasonal, then a well designed pond should help a great deal. I would think about adding a cistern for drinking water in addition.

That's 58 inches per year.

That is quite a lot of water. 1,5  meter about. My roof surface is 140m2. If i'd collect that all. I'd have 140x1,5=210m3. Say about 200 cubic meter. That's 200.000 liters.
Lots of water.
But with the rocky sandy soil, you'd need a liner or maybe cément.
Have you got a picture of your place you could upload?

It depends.

With a liner or with clayey soil a pond can be built to act like a pool. It will be filled with water in the rainy season, hopefully, and will dry sometimes. Or you could collect more water in a tank, and refill your pond with that water in the worst of the heat (need a big tank and a small pond).

Another option is to create a water harvesting landscape, potentially refilling underground waters, and it will surface at your pond (if done correctly). This has the potential to stay filled all the time.