Kinder Reservoir

I always like some numbers to interrogate. I was excited to notice a statistic about litres per day released from the reservoir but it's not the water extracted for people but that additionally allowed to flow on to keep the River Kinder moving. However, I have found that the reservoir serves 340,000 people http://corporate.unitedutilities.com/1511.aspx so using the idea that the average person in the UK uses 150 litres per day, we can estimate that 51 million litres per day are extracted for people. That is just over 2% of its capacity. If the catchment area is 866.7 hectares and a hectare is 10^4 square metres and that 51 thousand cubic metres are extracted per day (1000 litres in a cubic metre) then it lowers the water table by 51000/8667000=0.006metres or 6mm a day. This is similar to the number I got for the water extraction in the Forest of Bowland last month.