iolo wrote:

There is a tiny stream running through my lawn and the previous owner of
my house decided to turn it into a succession of six waterfalls and six
ponds. When I moved in water was gurgling over each fall, from pool to
pool, down the slope of the lawn. Two years later, however, only ONE
waterfall is working. All of the other five walls (mini-dams) which he
built out of small rocks and cement have developed leaks. Only one of
the ponds is currently full - and that's the one that is sending excess
water over the lip to fall into the next pond. But the rest of the
ponds are only almost full - their water is moving from pond to pond
through small holes in the walls. Each wall only has one or two
holes.

To dry up the stream in preparation for concreting repairs, by emptying
all the ponds, would be a back-breaking task, and anyway, diverting new
incoming water would be difficult.

So, is there some thick substance which I can ram into each hole and
which will then set solid, despite the pool of water on one side of
hole and the wet conditions on the other?

I have concrete, of course. And I believe one can get hold of
"plasticiser" to mix with it. But I am not sure if that's the solution
and if it is I'm not sure what proportions to mix it in.

Any ideas most gratefully received!


rubber roofing is about 1/8 in thick and cut to the size of the pool
bottom will water proof the bottom and allow the water to run over the
dam. rocks can then be put on this surface to hold it down and make
look natural.