WATER CATCHMENT AREAS 195 
relief to any great number of unemployed. It appears that 
the Bradford Corporation has spent enormous sums of 
money on the purchase of the land necessary for its exten- 
sive waterworks, and was not inclined to spend any money 
whatever on afforestation when this was put forward as a 
means for solving the difficult problem of unemployment in 
large towns. A pamphlet entitled “ Water Supply, with a 
Description of the Bradford Waterworks,” by J. Watson, 
was published at Bradford in 1900. See also Proc. Assoc. 
Municipal and County Engineers, xxiv. 128-132 (1898), 
and Trans. Inst. Water Engineers, xiii. 126 (1908). A 
good account of the Bradford Waterworks system, with 
maps, views, and plans, is given in The Engineer, vol. 119, 
pp. 251-254 and 278-280 (March 1915). 
Blackburn obtains its water supply from a gathering 
ground of 6820 acres in Bowland Forest in Yorkshire, 
comprising the watersheds of the Brennand and Whitendale 
Streams, tributaries of the river Hodder, at 550 to 1730 
feet elevation. The Corporation own 153 acres of the 
area, which is mostly moorland, without any plantations 
of note. Mr. W. Stubbs, A.M.LC.E., in Proc. Inst. Civil 
Engineers, vol. 194, p. 142, with map (1914), states that 
the geological formation is Millstone Grit, with outcrops of 
shale and in places of limestone, retaining the water for 
long periods. The annual rainfall at six different stations 
averaged for 1887-1912 from 55°63 to 71:06 inches. The 
water is not filtered, and no special measures are taken to 
prevent contamination on the gathering ground. No scheme 
of afforestation seems to have been proposed. See Fig. 37. 
Skipton Urban District Council obtains its water supply 
from a reservoir on Embsay Moor, with a gathering ground 
of 700 acres, entirely hill pasture and moorland, free from 
farms and other sources of contamination. The water is not 
filtered, but, owing to peaty discoloration, the Council are 
considering the question of filtration. The reservoir on 
Rombalds Moor, with 207 acres of gathering ground, of 
which 7 acres are plantations, is no longer used as a supply 
