Evaporation!!!

[max384]

i love your bog i think it's mostly evaporation since i actually lose about 0.5 inch yesterday and it was a very very hot day in the 95+ and high heat index. i dont know what that little wet spot is though. i think its a very tiny hole that water just seep through. i might try to use dye to see if it comes out.

The heat index is a measure of how uncomfortable (well, how hot) it feels because of the combined effects of the temperature and humidity. A high heat index relative to the temperature means that the air is very humid. A high humidity level will actually decrease the evaporation rate because the air is already so saturated, it absorbs water more slowly. It is, of course, still very hot though, but

Just to make sure I'm understanding this correctly. You lose 2" a day when the pumps and stream are running, correct? Now with the pumps and stream off, you lost 0.5" in a day, right?

With it being such a new pond (without a heavy plant load to suck up water), and now without running water, 1/2" sounds excessive to me. Did you set out a pan of water to measure evaporation as well, to use as a control?

I found a study on evaporation rates from around the country. http://www.nws.noaa.gov/oh/hdsc/PMP_related_studies/TR34.pdf

I'm not sure where you're located in NC, but the highest monthly evaporation rates were 7.4" in June. This is an average of less than 1/4" per day. Now, of course, running water will increase this rate, but still and running water rates of 0.5" and 2" per day, respectively, seem excessive to me. I wouldn't be satisfied with calling that evaporation if it were my pond.

Besides a possible leak in the bog, I'd assume there is also a leak somewhere in the stream or pump system, since an extra 1.5" per day is lost when the pumps are running. Keep in mind, with your sized pond (I think you said 12x15', right?), 2" drop per day is 225 gallons a day. That's a lot of water.

Try drying the backside of the liner with a towel. Then keep a towel behind the wet spot for a period of time and then see if you can more accurately pinpoint where the water is coming from, based upon what part of the towel is wet.

 

[Skydog]

What if you were to set up a similarily constructed kiddy pool and monitor it for evaporation?

 

[Nepen]

Thanks Max. that's very useful info. You are right that I dont have any plants yet. I thought the high evaporation in the bog comes from all the rocks/gravel gets very hot and heat the dry the water quicker than just the body of water?

I'm not super satisfy with the evaporation either so I'll do as you suggest for the wet spot.

I'll try Big Lou's methods one more time. I already made a hole in the pipe at the waterline (while pump stopped) to the bog so there should be no more siphoning back to the pond.

 

[tbendl]

What about using watercolor paint on the outside of the liner? See where the runnoff begins? Just a thought. I know I've used soap to find air holes but not sure it would work with water.

 

[Nepen]

What if you were to set up a similarily constructed kiddy pool and monitor it for evaporation?

I think the gravel in the bog (same level as the water) makes the water evaporate quicker so if I set up kiddy pool i'll have to put the gravel in there too just to have similar scenario I might be able to use something smaller, though.

 

[max384]

Thanks Max. that's very useful info. You are right that I dont have any plants yet. I thought the high evaporation in the bog comes from all the rocks/gravel gets very hot and heat the dry the water quicker than just the body of water?

I'm not super satisfy with the evaporation either so I'll do as you suggest for the wet spot.

I'll try Big Lou's methods one more time. I already made a hole in the pipe at the waterline (while pump stopped) to the bog so there should be no more siphoning back to the pond.

I'm not sure about higher evaporation rates from the bog. I don't have a bog myself, and don't possess any knowledge on building or maintaining a bog. It makes sense the explanation that you gave, but it still seems far too high of a water loss rate to me...

Based on my own experience, and seeing the pictures of your stream, I'd be most concerned about water loss from the stream, due to low edges.

As much as we love our ponds, ponding can sure be a big chore sometimes...



EDIT: Also, when you were giving water level drop figures, were these from the bog, or from the pond? If from the bog, are you sure that there is no water going back into the pond?

 

[addy1]

Good luck Nepen, all I know is only in the summer, if I do not add water every day for 38 minutes, the pond drops in level, it does not drop at all in the winter or spring until the heat hits. I add less water in the fall as the temperature cools, I adjust the amount added.

 

[Nepen]

What still puzzle me is that the wet ground is not very wet.. considering I have clay, a little water will make clay go soft and clay-ee but the wet spot was just damp and the clay didnt seems to be 'wet' for the amount of water that supposed to leak out.

 

[Nepen]

Hi Max,
The first day when the water in the bog dropped to the bottom, I figured that it was a big leak but then I found that it was the siphoning back to the pond. So I broke the siphoning and re-filled the bog and set the water level again. Then I got 0.5 inches water lose that day. The water lose is from bog. The same day I think the pond water lose was less than the bog. (no running water).

When I lose 2 inches I actually found low spots on the liner and fixed that so I'm not sure how much I'd lose now with that fixed.

Pond is sure a chore but it's a chore I love


Thanks Addy. It's frustrating trying to figure this out. I'm running the pond again today... will see how that goes...

 

[addy1]

My only constant leaks is in the spring and is the stream, darn deer walk in the stream rearrange the rocks, eat the plants, squish down the side (I even have put rocks under the liner). It is part of my spring maintenance to walk the stream while it is running, move the down slope edge rocks and look for flowing water. Every spring there is some.

 

[Nepen]

Good to know Addy, since I have deer visit well, I do have kids visit and my son LOVES the stream and play in the bog and stream almost everyday. MAY BE that's where my pond leak was lol.


I found this.... Since I cant find the leak may be I should coat the whole area where I think the leak is with this?

http://www.amazon.com/Pond-Pro-2000...&qid=1434639958&sr=8-1&keywords=pond+pro+2000

 

[Mmathis]

@Nepen I was going through YouTube earlier, not even looking for pond stuff, and I found a couple of Pond Digger Q & A videos where he talked about evaporation. Mostly stuff that's already been brought up, but a few new things to think about. He does explain about the various ways evaporation happens and covers some good info.

(And there was even a short YT video about a koi -- they called it "smart" -- that would go into a skimmer to eat, then pop back out again. Just like my silly Watonai! Amazing that more fish do that!)

 

[Nepen]

TM, do you have a link to the evaporation YouTube? Thanks!
Skills fish you got. I have one that went there to eat tadpoles but my skimmer is big and wide so there's no problem coming back out. (Not calling it skimmer yet coz it doesn't work right)

My husband agreed that the ground should be more muddy if I really lose that much water out to the side. The water in the bog was like bath water, very warm.

I don't know. I still keep an eye on the wet spot near the bog but is been raining for 2 nights now so I can't really do any test now.

I might turn off the water at night the. Try koi clay and see if it'll just seal up my liner for me lol.

 

[Mmathis]

@Nepen, will try to find that for you for that for you. I ended up there by accident -- you know, how you start out looking for one thing on YouTube and you end up so far off track that you forgot what you were originally looking for...... [With me, "off track" is usually looking at funny cat or ferret videos, LOL!]

But basically, I went to YouTube, got interested in something by PondDigger, so did a search of just PD videos.

 

[Mmathis]

Here ya go!

Pond Digger - evaporation

Pond Digger - leaks

Not the end-all solutions, but worth watching.