I have heard from Nick Kite that Mott McDonald Bentley expect to finish the remedial work on the reservoir outflow in early December (2019). The plug goes back in then. According to Wikipedia Llyn Brenig’s catchment is over-reservoired. This means that the reservoir cannot fill from its own catchment within one annual hydrological cycle. Our climate is clearly changing with heavier rainfall and I suspect that the water level will be nearly optimum by the time we start the 2020 season.