Several internal drainage boards in North Somerset noted low water levels in the river Kenn system in July last year and reported this to the Environment Agency. An investigation found that a measuring gauge at Kenn Moor Gate was registering only five litres a second instead of the minimum flow of 51 litres a second.
The flow is a condition of Bristol Water's abstraction licence and the company should not take water from its borehole at Chelvey Well unless the minimum flow is exceeded. It later transpired that the company was taking 13,000 cubic metres of water a day from the groundwater feeding the river.
In mitigation, the company said that a telemetry failure at the measuring gauge led it to believe the flow was much higher. However, Bristol Water was further embarrassed when it came to light that it was ignorant of the terms of its abstraction licence: it believed that the minimum flow was 34 litres per second rather than 51.