Looking for the Leak

Our pond has a pump which pumps the water up to the stone waterfall at the top of the garden and the water cascades down to form a stream ending up in the pond again. At least that is what did happen until last year.

When we switched on the pump last summer the water flowed and the pond level dropped dramatically. A friend is pushing for us to thinks we should find the leak and get everything working again before the garden is open as part of Stokesley's Open Gardens at the beginning of June. So this morning he turned up with a length of piping which was attached to the pipe behind the waterfall in order to work out if the leak is between the pond and the waterfall or between the waterfall and the pong. The result was that the pond level didn't drop which means that the leak isn't under the garden (phew!) but somewhere in the stream. At least all that means is that we need to remove all the pebbles and see if we can find the leak in the liner which is under them. If it had been between the pond and the top of the waterfall I don't think we would have even tried looking for it.