156 



REPORT 1879. 



their labours become known, the greater inclination is shown by engineers 

 and contractors to furnish information, and the greater tendency is 

 exhibited to make available our underground water for the purposes of 

 consumption. And they are of opinion, that until it becomes the duty of 

 a Government Department to collect the various information accruing 

 from day to day, it is important that the Committee should be reap- 

 pointed, and further that their inquiry should not be limited to certain 

 formations, but should extend to the whole of the permeable formations 

 of England. 



The attention of your Reporter has been specially given since the last 

 meeting to the estimation of the areas of water-bearing formations in the 

 various river-basins, and to the extent to which they may be expected to 

 underlie the more impermeable clays and marls ; towards this object he 

 has personally examined a large area of the country, and endeavoured to 

 ascertain how far the rain falling in certain river-basins is carried by the 

 dip into other hydrographic areas. These results he is prevented laying 

 before you in detail through illness, brought on by a railway accident; 

 but the following totals may be found useful, giving the Permian and 

 Triassic formations in fourteen groups of the 215 river-basins of the 

 Ordnance Survey Catchment Basin Map : — 



Of the 3041 square miles of Trias in the Ouse and Trent basins, 200 

 of Red marls probably rest directly on the non-water-bearing Palaeozoic 

 rocks of Cbarnwood Forest age. The 11 71 square miles of sandstone, 

 at 5 inches absorption, would give a daily average of 234 million gallons, 

 or a supply for four-and-a-half million persons ; the population is probably 

 not less than six millions ; the demand is here in excess of the supply, the 

 deficiency is made up by moorland surface waters from the elevated table 

 lands of the Penine chain. The underground supply is, however, only 

 pumped to a fraction of its yielding capacity. 



In the Severn and (Bristol) Avon basins 438 square miles of sand- 

 stone, with 10 inches' percolation, would yield a supply for three-and-a- 

 half million persons, at fifty gallons per head ; but part drains away 

 underground into the Trent basin, between the north and south Stafford- 

 shire coal-fields in its northern area, and into the Thames basin in its 

 southern area. The Triassic sandstones in the south-east area towards the 

 Thames basin are thinning rapidly, and much of the 1393 square miles red 

 marls is not supra-pervious, and rests on Palaeozoic impermeable rocks. 



South of the Mendips 315 square miles of Triassic sandstone crop to 



