314 



REPORT — 1881. 



feet 



Light blue clay and sand 4 



Light blue clay 27 



Dark blue clay 19 



Clay and sand 4 



12 



The South Wales streams draining into the Bristol Channel, are 

 inhabited by a population of about half a million, requiring 15 million 

 gallons of water daily. 



The West Wales river basins, from St. DaAad's Head in Pembi'oke- 

 shire to Carmel's Point. Anglesea, drain an area composed entirely of 

 impermeable rocks, and contain a population of about 180,000, distributed 

 in the coast counties from Pembroke to Anglesea. 



The North Wales river basins from Carmel's Point to the Point of 

 Air, are inhabited by about 175,000 people, requiring 5^ millions of 

 gallons daily. 



Following the river-basins from west to east, the Clwyd is the first 

 that contains any Triassic rocks, occupying about 71 square miles of this 

 area. From the thick covering of Boulder clay, probably not moi'e than 

 30 is available, as an area of absorption ; the rainfall of the area is small, 

 and the quantity available not more than 5 inches per annum, or 200,000 

 gallons per square mile, or an average of 6,000,000 gallons per day over 

 the available area. 



River Basins of the N. W. of England. 



