Thursday 31 March 2011

27th Feb 2010: WESTERN POWER BEGINS EMPTYING LLANISHEN RESERVOIR.

Yesterday, Western Power began emptying Llanishen reservoir.  They have set up pipes through which they are pumping water over the embankments into the Nant Fawr. It seems they can draw off the top three metres of water without requiring permission, but thereafter need to obtain a drainage consent from the Environment Agency.  The reservoir engineer who has been employed by RAG estimates that there will be a minimum of 10,000 cubic metres of silt on the bottom of the reservoir.  If only a small fraction of this is washed into the Nant Fawr it will do enormous environmental damage to the stream and it will all end up in Roath Park Lake, adding to the silting problems there. Draindown could not have come at a worse time for the exceptionally large population of toads which normally breed in Llanishen reservoir.  Within the next two weeks they will be migrating to their traditional breeding site to spawn.