234 FOEESTS, WOODS, AND TEEES 



removed. This catchment area could probably be afforested 

 with profit, and in any case ought to be owned by the Council. 



The Wrexham and East Denbighshire Water Company 



obtain their supply in part from the Pentrebychan Brook, 

 with a gathering ground of 1500 acres, on the Esclusham 

 Mountain, between 900 and 1500 feet elevation. The 

 ground, none of which is owned by the Company, is all 

 barren moorland on millstone grit and limestone, without 

 houses or farmsteads. There is said to be no possible 

 contamination. The water is first settled in an impounding 

 reservoir at Cae Llwyd, Esclusham Above, then decanted 

 into the Ty Mawr reservoir and finally filtered through 

 slow sand filters. 



Birkenhead obtains its water supply at present from 

 wells and borings in the New Eed Sandstone formation ; 

 but an additional source of supply from a gathering ground 

 of 6300 acres on the head- waters of the river Alwen in 

 Denbighshire was authorised by the Birkenhead Corporation 

 Water Act of 1907; and the necessary works, including 

 reservoir, mechanical filters and tanks, are now being con- 

 structed. The Alwen catchment area is situated between 

 1190 and 1760 feet elevation, and consists mainly of 

 moorland, more or less covered with peat, which varies in 

 depth from a few inches to many feet. Below the peat on 

 the south and west is generally boulder clay; elsewhere rock 

 and shale prevail. About 550 acres only may be classed 

 as arable and grass land, there being a little cultivation on 

 the north and east sides of the watershed, and about 

 100 acres of woods and plantations on the north-east side 

 of the valley. There are eleven houses and farmsteads on 

 the gathering ground, five of which belong to the Corpora- 

 tion ; and of the latter, two near the margin of the reservoir 

 will probably remain uninhabited. 



The Corporation own 2600 acres, including some land 

 below the reservoir, that drains to the river Alwen. Of 

 this area, about 375 acres are covered with the water of 

 the reservoir. Prof Eraser Story estimates that about 



