Yay we got some rain and it 1/2 filled my leaky dam! Has anyone used any dam sealants that you put into the a full dam to seal the leaks? I am wondering how natural /organic these are? Dam is very rocky. Any experiences / thoughts? Thanking all in advanced.
I have successfully used bentonite clay mined here in Queensland near Miles. The dam, about 500000Litre capacity, so not large, was in a lateritic scrub soil derived from decomposed basalt and very weathered, the original vegetation was wet schlerophyll eucalypt forest with tallowwood and sydney blue gum dominant with black wattles but the clays in it were not suitable for water holding purposes, so emptied the dam with a big excavator bucket and spread by hand several tonnes of the fine white bentonite clay powder about 15mm deep all over, starting at the lowest point, then sprayed with water to form a crust and the dam pumped full from another dam nearby, then fenced from livestock. That was in 1990 and the dam still holds water and is used as a fish and yabby pond. You can still dig up the bentonite underneath the now 300 mm coat of organic matter and other dam detritus. Used about 3 cubic metres of bentonite purchased in I tonne poly bags, about 3-4 tonnes or more probably. Bentonite is used in many things from cattle feedlot rations to drill mud, concrete and ceramics, medicines... In hindsight I probably overdid the bentonite and could have got away with half with a better spread technique other than broadcasting, but at the time I was a newby and the client was good at spending money. You can buy it in 25 kg bags or in bulk. Not so sure with the rocky bottom, maybe a coat of sand or soil and organic matter over the rocks first, then a dam liner instead of the clay may be cheaper?
