Large Pond

[Comet]

Hello,
Today I met with a management board re; to a 13,000sqft pond located in a co-op development
They indicaded they needed a new liner.
They indicated the pond was constructed 25 years ago and has an old clay type liner or clay base....
There is no plants nor is it stocked with any fish.
Just had a big spray in the middle

The real reasoning behind needing a liner wasnt expressed with accurate data to justify it..

*some in the development complained of seeing unknown wild plant life sprouding up in the summer time along with being very unsightly looking at that.

*The managemnt said that the maintenance dept there has noticed a drop in water level and has been ADDING water to this huge pond all summer long (with a garden hose) and while tryng to clean the top surface of _______ just creates and disturbs the bottom making it even more unsightly looking.

I may never get to work on this project (due to its enormous size)

but would sure like to know for future jobs,,,what type bottom
could they be refering to this really having?
What did they do 25 yrs ago in constructing these
I place my hand in many places elbow deep to find a 6 inch covering of sand or muck and beneath that a ROCK hard base of I suppose of clay,, It wasnt penitrable by hand...

Im sure it was clay, I have dealt with clay before doing foundations

Can this pond actually just have a clay base bottom? and hold up? Possibly so close to the water!!

I didnt see any liners and dont think it ever had one,, nothing came up over the edges and the edges.. bedides there was nothing along the edge to hold a liner

There is 3 large culvert type drains on opposing sides leading to (______unknown at this time)

This management assocition wants to have this problem resolved and fixed,, Id love to be able to propose a proposal and be awaded the job

I was there with 2 other contractors that showed up,,
I was the only one who measured the area, took pictures and stuck my hand in he water,,it was freezing cold lol
One was a fellow with no hand tools,,another was a sprinkler irrigation company and then there was me; the one who stuck his hand in cold water like a jerk lol
This job may just need proper thourogh maintenance from a boat or
Maybe its just evaboration and not leaking

This is realy close t the south shore, close to the water.
I did some gunite pools years back similair area and we had to have pumps running all the time draining the water level as we where working

I can see this happening here
I just viewed this today 11/9 and will have site plans faxed to me
Any info is appreciaated,,
Just maybe I can take the job on maybe not,
thanks

[Stonehenge]

My knowledge on this is really shakey but I'll give what I have -

Ponds are/can be lined with bentonite clay. It's supposed to not let much water through because it's really dense, but it lets some through.

I don't know the water table level there, but if it's really low, it's possible that the pond is losing water into the ground. If they want a new liner, aquascapes can set you up with a 20 or 30 mil liner that I believe can be heat gun welded at the seams. I believe the honcho there has a 1 acre pond himself. But then you would have to provide for water supply into the pond, because in a closed system like that, the water will evaporate. You'll also need to create some sort of stream/waterfall to provide for filtration of the water. Not a hinderance as much as it's an opportunity to do something eye-catching in the pond.

But make sure they know they're in for some real $$. We just did a small (20'x20'), underpriced pond/stream/waterfall for $7K+. I can't imagine what 13,000 sqft would price out at. Probably over $100K.

[Comet]

Imformative thank you,
Im doing some resarch on bentonite clay

Most likley then without a doubt it was construted "within specs "with that type base material or similar. Thanks

The other one up front by the main gate entrance,, Its over 88,000 sqft kidney shaped with a walkover bridge.. I took 10 pics of that one (there is no problem with that one yet)

*I knew Aquascape sold large custom orders for large projects
*I will contact them for a aprr price quote for starters but that will just be starters. etc..

I may need for this one an estimate fee up front if there is any type of green light,, I can imagine how much work I could spend on this.

Your comment that it may be leaking back into the ground may be the actual problem that exist for the loss of water..
Wonder how can one prove it or if it NEEDS to be proved before such an expensive renavation,, hmmm

The water table there has to be just at that elavation,,

Would a liner still work in this case or would you think adding to specs once AGAIN on top of the existing clay,, NEW hauled in clay
thus elimainating the issues at hand with covering and hiding the liner up on the edge?
may be still too big to handle , ill give an old friend a call
thom

[dan deutekom]

The pond probably is lined with bentonite clay. It seems to work well but if it drys out for some reason it can crack and lose it's seal. I have read somewhere that it is possible to repair this type of lining by spreading bentonite over the surface of the water and letting it settle on to the bottom of the pond. There is a lot of info on the net if you type bentonite into a search engine. I did this a year ago when I had a similar problem with a much smaller pond. I ended up lining it with pond liner because we ended up changing the complete design.

[Comet]

Thanks for your responses,

As it stands;
The construction engineer's have sent out out site plans to everyone.

*Its a deffinate water seepage confirmed,

*The staff from the co-op will be responsible for draining the pond at a later time and date (spring)

*I have seen out of Arizona someone sent me valuable info on another alternative method of utilizing a product called ESS-13 , a liquid polymer emulsion that has been succesfully used when builing large bodys of water or repars along with also utilizing the natural clay bentonite
http://www.seepagecontrol.com/

*They know it will be an expensive repair with heavy extensive equipment, material and expotese,,

*Oh well, something to learn and read upon over the winter

Thanks
Thom

[Stonehenge]

Are you still going to take a crack at it?

[Comet]

Oh Yes!!, Ill try,, I'll contact this friend in the Bronx with heavy equipment for starters, see wherethat leads then contact a few others
Maybe I can work something out with him. just maybe,
(if I can still locate him the dawn guy owes me big time)

The place is already bulldozed to its required shape and form with all the drains installed/completed

Still need heaviy rollers and spreader's per say and expotese.

In the begining I thought this was the normal size pond needing a liner.

Getting bondable for this enormous job may be a problem :(

Thom