2 2 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



5. Afforestation of Catchment Areas. ^ 



The supply of water obtained from land forming a " catch- 

 ment area " is materially affected by the planting of trees. It 

 has been found that the moisture in the soil underlying trees is 

 much better conserved than it is in open country, so that more 

 water drains from a wooded area than from one devoid of trees ; 

 while, in addition, the flow is maintained more equably through- 

 out the year, thus tending to prevent floods on the one hand, 

 and water-famines on the other. In addition to the direct 

 improvement of these areas in point of suitability for the supply 

 of water, the sale of timber may become after a time a relatively 

 important source of revenue. 



These considerations induced the Departmental Committee 

 on British Forestry in 1902 to recommend that the attention 

 of corporations and municipalities should be drawn to the 

 desirability of planting with trees the catchment areas of their 

 water supply, and in communicating this recommendation to 

 the Local Authorities the opportunity was taken to ascertain 

 some particulars as to the area and character of their catchment 

 areas. These particulars were given in the. Journal of the Board 

 of Agriculture, November, 1904, p. 468 ; and with a view to ascer- 

 taining what steps have been taken since that date, the Board 

 of Agriculture and Fisheries have recently asked the Local 

 Authorities principally concerned for an account of any work in 

 the direction of planting the areas under their control which has 

 since been carried out. 



The result of the inquiry shows that in the majority of cases, 

 even where Local Authorities are in possession of the freehold, 

 or have long leases of their catchment areas, very little progress 

 has yet been made. In a few cases, on the other hand, the work 

 has been taken up seriously, and planting is being done on a 

 systematic plan. 



Leeds. — The catchment area of the Leeds Corporation is 

 situated in the Washburn Valley, and extends to over 11,700 

 acres, varying from 350 feet to 1550 feet above sea-level, and 

 lying on the Millstone Grit overlaid with boulder clay. The 

 work of afforestation was begun here with a view to giving work 

 to the unemployed, and has been carried out for three seasons 



^ Reproduced from the Journal of the Board of Agriculture, by permission 

 of H. M. Stationery Office. 



