Llyn Celyn
As demand for water increased it was necessary to increase the storage on the River Dee and the next development was Llyn Celyn, a new 81,000,000-cubic-metre capacity regulating reservoir within the Bala Lake catchment area. This was completed in 1967 by Liverpool Corporation, and designed to operate in conjunction with the Bala Lake Scheme. This enables additional Dee abstractions of 327,000 cubic metres litres per day together with additional flood control storage. In summer time the impact was to increase threefold the dry-weather flow for most of the length of the river. This development was hugely controversial at the time and remains politically fraught to this day since the construction of the reservoir involved flooding the Tryweryn Valley and the village of Capel Celyn and twelve farms. Local people saw this a destruction of part of the Welsh culture in order to supply England with water. This caused a great deal of controversy, resentment and protest. To try to offset some of the environmental concerns associated with the scheme, some of the stored water was specifically set aside to make special releases to help fisheries, to provide recreational opportunities (canoeing and white-water rafting on the Afon Tryweryn) and to disperse pollution events should they occur.
A four megawatt hydro-electric station at the dam was also included in the scheme.
Read more about this topic: Dee Regulation Scheme