Finding waterfall leak

[Kat-mac]

Fixing the waterfall has been on my to-do for awhile. I'm going to do a careful bucket test this weekend to confirm and get a baseline. But here's and overview.

I have an inground pool and waterfall. Every time I have turned on the waterfall pump, the water level seems to drop. Some was the masonry on the back side, and that was fixed professionally. The leak is noiceably better (and there are no longer any wet areas behind the feature), but it seems like the water level still drops when the waterfall pump is running compared to when it's not running.

1) Is there a certain amount of water drop that is expected from increased evaporation/splashing of a water feature? For example, I have a standalone fountain that I have to replenish regularly, due solely to evaporation and splash. I live in a semi-arid desert area, so humidity and rain are very low. If so, how can I distinguish between that and a leak?

2) As the water flows over a wide area (a few feet), how do I find the leaky spot, to know where to patch it? My local pool store will help me get the right materials for patching, but I need to know where to focus.

Pics are attached. I drew on one to show approximate water flow. (I need to clean out the leaf debris before I turn it on.)

 

[ajw22]

How much water are you losing in what time period?

You have to log the wind speed and air and water temperatures and relative humidity during that time to determine what the natural evaporation would be.

This wiki give some tables of the impact of wind and temperatures on evaporation along with linking to a spreadsheet to do calculations.

Evaporation of Pool Water - Further Reading

www.troublefreepool.com

 

[Kat-mac]

I will do a bucket test this weekend with and without the waterfall pump. Assuming it is a leak, just wanted to get a jump on how to locate it.

Thanks for the link on evaluation. That will help me assess it!

 

[mknauss]

I would be careful on using a bucket test for this. The surface area of the water fall and the heat of the waterfall concrete/rock will greatly enhance the evaporation of the pool versus the evaporation from the bucket.

 

[Kat-mac]

I would be careful on using a bucket test for this. The surface area of the water fall and the heat of the waterfall concrete/rock will greatly enhance the evaporation of the pool versus the evaporation from the bucket.

Do you have a suggestion on how I can figure out if it's a leak vs evaporation?

 

[Kat-mac]

Just an update: I don't think there is a leak. Bucket test was only 1/4" drop (if that) with it running 24h. I have left it on and it runs whenever the main pump is on with no noticeable change in water level.

 

[Cfallwell]

You can always plug the ends, add a psi gauge and pressure test the lines to know for sure. The air pressure is also good for finding the leak by listening for the sputtering