WATER CATCHMENT AREAS 233 
Conway and Colwyn Bay Joint Water Board obtain their 
supply from Lake Cowlyd, 4 miles from Llanrwst, with a 
gathering ground of 1100 acres, between 1169 and 2621 
feet elevation. The highest points on the gathering ground 
are Pen Llithrig-y-wrach (2621 feet) and Cregiau Gleision 
(2213 feet). The area, which is owned by the Board, 
includes 200 acres of lake and 900 acres of moorland, and 
is without habitations, farmsteads, or plantations. The 
water is passed through copper screens, but is not filtered ; 
and precautions against contamination on the gathering 
ground are considered unnecessary. The annual rainfall 
from 1891 to 1906 varied between 58°50 and 114:30 
inches, the average being 76°61 inches. The catchment 
area was purchased to do away with a farmstead that was 
on it, and to give the Board full control. It is now only 
used as a sheep-walk, and owing to its elevation and 
distance very few visitors find their way up there. See 
T. B. Farrington, in Proc. Inst. Municipal and County 
Engineers, vol. 33, pp. 200-207 (1907). 
Llandudno Urban District Council obtains its water 
supply from Lake Dulyn, at 1747 feet elevation, and Lake 
Melynllyn, at 2094 feet elevation. The united gathering 
grounds, 710 acres in extent, are entirely moorland at a 
very high altitude, and together with 730 acres adjoining 
(1430 acres in all), are owned by the Council. An experi- 
mental plantation of half an acre has been made at 1650 
feet elevation. The water is not filtered, but the gathering 
ground is frequently patrolled, twice a week in summer, 
and once a week in winter. 
Rhyl Urban District Council obtains its water supply 
from a gathering ground of 900 acres at Llanefydd, between 
485 and 1000 feet elevation, of which 50 acres are owned 
by the Council. The area comprises 100 acres of planta- 
tions, 200 acres of hill pasture, and 600 acres of arable 
land, with small farms upon it. The water is filtered; and 
on the gathering ground, the farms, which have intercepting 
tanks, and the streams are inspected, and excreta are 
