WATER CATCHMENT AREAS 199 
when the war began, which is held over until more favour- 
able circumstances return. 
The Annual Report of the Keighley Waterworks, by 
M. Ratcliffe Barnett, M.Inst.C.E., published in August 
1915, gives a complete account of the various undertakings 
and is accompanied by a map. 
Halifax has four moorland gathering grounds, with a 
total area of 7322 acres, as follows: 
1. In the Hebble Valley, Ogden reservoir, at 990 feet 
elevation, serving for compensation and domestic supply, 
has a catchment area of 1140 acres. Mixenden reservoir, 
875 feet elevation, domestic and general supply, has a 
catchment area of 190 acres. 
2. In the Luddenden Valley, Fly or Warley reservoir, 
1350 feet elevation, compensation, has a catchment area of 
919 acres. Lower and Upper Dean Head reservoirs, 975 
and 1000 feet elevation, domestic and general supply, have 
a catchment area of 525 acres. 
3. Widdop reservoir, at 1050 feet elevation, on a stream 
of the same name, also receives by a tunnel the water of 
the Greave Valley, and serving for compensation and 
general supply, has a catchment area of 2223 acres. 
4, Lower Walshaw Dean reservoir, 965 feet elevation, 
for compensation, and Middle and Upper Walshaw Dean 
reservoirs, 1043 and 1100 feet elevation, for general supply, 
have a united catchment area of 2325 acres. 
The whole of the gathering grounds, the lowest point of 
which is 875 feet elevation, are either moorland or mountain 
grazing over Millstone Grit. The Corporation own only a 
part of the area, viz. 1310 acres, all in the Hebble 
Valley. The eminent botanists, Mr. W. Crump and 
Dr. W. G. Smith, who have done so much excellent 
work in plant ecology and in producing vegetation maps 
of Yorkshire, etc., strongly urged in 1902 the afforestation 
of these gathering grounds. In that year 38 acres at 
Ogden and 12 acres at Mixenden were planted, to which 
37 acres were added in February 1909. Success was 
