WATEE CATCHMENT AREAS 235 



600 acres of the Alwen area might be profitably afforested. 

 The afforestable area faces north and east, excellent shelter 

 being afforded by a ridge which runs parallel to the lake. 

 The range of hills, composed of Craig-yr-Tycheu, Ten-y- 

 bwlch, Mwdvvleithin and Pen-bwlchygarnedd, is situated 

 immediately to windward. The sheltered situation counter- 

 acts to a great extent the influence of the high elevation, 

 1200 to 1500 feet. Many parts, chiefly near the sources 

 of small streams and in the hollows, covered with accumula- 

 tions of peat, must be excluded from any scheme of 

 afforestation. The area previously occupied by Llyn 

 Dauychain, in which the peat from the bottom of the 

 reservoir was deposited, and some swampy land, must also 

 be excluded. The soil is suitable for the growth of spruce, 

 especially Sitka spruce ; and some of the lower slopes might 

 be advantageously planted with Douglas fir. About 75 per 

 cent of the west side could produce timber profitably. The 

 cost of planting, including young trees, drainage, and 

 ordinary fencing, was estimated in 1915 at £6 per acre. 

 The annual rainfall was about 46 inches in 1911, 1912, 

 and 1913, and 55-12 inches in 1914. 



The Corporation have authority to construct another 

 reservoir in the Brenig Valley in Denbighshire, having a 

 separate gathering ground adjacent to the Alwen watershed, 

 5600 acres in extent, and situated between 1067 and 

 1700 feet altitude. This catchment area, of which the 

 Corporation own about 4400 acres, will not be utilised at 

 present for water supply ; and no report as regards its 

 suitability for afforestation has yet been made. 



Brymbo Water Company obtain their supply from three 

 upland surfaces, 686 acres and 873 acres at Llandegla, and 

 42 acres at Llanarmon, making a total of 1601 acres. I 

 have not been able to obtain any particulars of these gather- 

 ing grounds, which appear to be mainly moorland and hill 

 pasture. The water is filtered. 



Ruabon Water Company obtain their supply from an 

 intake of the Trefeehan Brook on the Ruabon Mountain, 



