Right from the beginning there was water in the inspection pit. This was the lowest point of the building and spent the first couple of months thinking this was just rain water coming in under the door. After a lot of head scratching and leaving dry sand around the perimeter of the inspection pit I realised this was ground water seeping through the conrete blocks of the pit to fill it by generally a few centimeters.

The water could be bucketed out in a few minutes but would return over the next day.

As I started excavating (May 2007 onwards) the lowest point of the building would flood so I built a little 12v operated water pump which was happily keeping the basement dry until November 2007.

In November 2007 work started to connect me to the public sewer. I'm having a really deep sewer so quite a serious excavation was needed. I assumed this would result in more ground water which would flow down the pea gravel bedding the sewer pipe but I wasn't ready for what happened next. 15,000 litres per day flowed into my basement. There was no way the little 25 watt pump would cope so I got a 500 watt mains powered pump. Knowing nothing about ground water I assumed this would stop after a couple of days once locally saturated rock had drained but it didn't. The photo above shows my basement the day after the pump failed. 18,000 litres of water. I was having real trouble dealing with this for a week and then the cause was discovered. A split water main about 10m away. The split could have been caused or enlarged by vibrations during the sewer excavation work but more likely it was a really old water main. Once reported, the water company acted very quickly fixing it the following night. I am hoping to use ground water to flush the toilet and keep the house cool during the summer (regulations etc. permitting) but I no longer know how much ground water to expect. The original ground water back in May 2006 could have been the start of this mains leak.