There hasn't been much rain over the last few months but even with what little there was I had not expected the level in the watertank to drop so rapidly. As we do depend on rain for our water, there was only one solution: drink more beer and wash less.
Today came the first good rain - some 10 mm - and I knocked on the tank to check if there was enough water for my first shower since Christmas (only kidding! I had a short one at Easter ☺)
According to the formula of 1mm of rainfall on 1 square metre of roof area putting 1 litre of water into the tank, this short downpour should have added at least a thousand litres to the tank but there had been none. Then I discovered the problem : a leak in the diverter.
When I had bought the tank all those years ago from RAPIDPLAS, I bought it with one of those 'First Flush' thingos which fills up with the first seventy-or-so litres of 'dirty' water washed down from the roof before then overflowing into the main tank. Well, this one never overflowed because it had sprung a leak and instead of diverting just the first seventy litres, it diverted the lot - through the leak.
I have now 'jury-rigged' the downpipe directly into the main tank, dirty water or not, while I think of how to fix the 'First Flush' thingo which clearly is no longer in its first flush.