Since 2002 I have been keeping a weekly check on the level of water in the hole. I built a depth guage and installed it some years ago. A display in the shed shows the depth in intervals of 0.2 metres up to 1.5 metres - when I built it that seemed reasonable but I installed it in a dry summer. Now, when the water level exceeds 1.5 metres I open the trapdoor and measure the depth manually.
