Dam Water Changes Colour ?

[njrqs]

Hi all

My dam here is a small one. When we moved in I am sure the water was a nice deep green type colour. Looked nice.

After we had some excavtion works done around the dam, it was then all brown next time it filled up. Light brown like rivers in flood colour.

The next time it filled it was brown too.

It filled on Boxing Day and was they silty brown colour.

We have just had 10 inches of flood rain over the last few days (hooray as we it was drought before that) and now the dam is back to the nice deep green colour.

What is going on here?

Filled brown and then turns green a few weeks later after heavy rain.

Could it be all the silt runs with the first runoff then all that is left is clean water? /forums/images/graemlins/confused.gif

 

[StoneHeartFarm]

Maybe an algae bloom? I heard you guys got some rain, really needed it too.

Steve

 

[njrqs]

Nah, I should clarify that the deep green is a real nice colour, like you'd see in a freshwater creek or something.

Not algae but just clean water.

I haven't been here long enough and had enough rain to see any trends but it has me puzzled.

Yes we had floods in our part of the state. The rain from last Wednesday to Friday was more than half the total rain we had last year !!

Cheers /forums/images/graemlins/grin.gif

 

[Egon]

Neil:
It could be the sediments in the water that have produced the colour change.

Mountain lakes change colour over the summer due to meltwater sediment.

Egon

 

[beenthere]

Sounds like the sediment, that is in suspension, is settling out of the water which is the carrier (that is where the silt at the bottom of the pond comes from), leaving just the clear water.

Try taking a large glass or jar, and dipping out some of the water when it is "brown" the next time, and watch to see what settles out.

But the pond sounds like it is looking pretty good, with the good water color. /forums/images/graemlins/smile.gif

 

[StoneHeartFarm]

Neil,

You guys needed the rain pretty bad.

I'm not thinking about algae in the water, but in the sediment (or, rather on top of it). I'm just wondering if after the sediment settles, something starts to grow.

Steve

 

[njrqs]

Nah, the water stayed brown last time for the whole 9 months until it dried out. Very brown for the whole time.

Filled 5 weeks ago and was brown the whole time till this heavy rain and now clean.

Hmmmmmmmmmmm /forums/images/graemlins/confused.gif

 

[Dozernut]

Did you make an old Gypsy witch mad, so she cursed your pond /forums/images/graemlins/shocked.gif? Maybe you have a "Mood Pond". You know, like the mood rings from the 60s' and 70s'. Drought = bad thoughts = brown water, rain = good thoughts = green water. All of this scientific thought is making my head hurt /forums/images/graemlins/crazy.gif, but I think I'm on the right track. Gday mate! /forums/images/graemlins/smile.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/laugh.gif

 

[fishman]

It's possible that tannic acid might be responsible. If the water is brown in color, but fairly transparent, that is the case. This is caused by leaves and other detritus.

It's also possible that the clay particles in the runoff are electrostatically charged and won't settle out without a little help from you.

The green color is natural, and is the result of pelagic phytoplankton (read: single-celled floating algae) in the water. This is most noticeable during warmer months, and is generally most pronounced when there are nitrogen and/or phosphorous inputs to your pond.

A visit to pondboss might prove useful

 

[yaouk]

A dam with water in it.... whats that like? /forums/images/graemlins/wink.gif

We are just starting to get a bit of rain up in the mountains. If it puts the fires out I'll be happy. Creeks and dams we'll worry about later.