WATER 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-Tychen, Ten-y- 
bwleh, Mwdwleithin 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 Trefechan Brook on the Ruabon Mountain, 
