690 report — 1878. 



overcoming hostile opposition (based upon increased flooding) to its being executed 

 in divisions instead of in one unmanageable whole. Of this work two divisions have 

 already been sanctioned by Parliament and are now nearly completed. The object 

 of the author in bringing forward these facts is that the practicability of dealing 

 with large river systems in divisions, instead of in one whole, may become more 

 universally known and acted upon. 



3. On the Control of Rivers* By W. Shelford, M. Inst. G.E., F.G.S. 



™ The author divided the subject under two heads — I. Tidal Rivers. After 

 showing that the importance of British rivers was due to tidal water, and that the 

 tidal portions of them had been subject to the care of the Government as early as 

 Charles II., he gave instances of the divided control which existed down to 1867 

 between the several departments of the Government itself. 



He alluded to the Thatnes as a case where the controlling bodies — the Thames 

 Conservancy and the Metropolitan Board — were now divided even as to the fact of 

 the existence of sewage pollution ; and he referred to Smeaton's Grand Sluice on 

 the Witham as an example of injury undoubtedly done a century ago, and still 

 felt, through the divided control exercised by the land and navigation interests. 



Passing on to the Fen rivers, he gave in considerable detail the results of an 

 attempt to improve the Nene on sound engineering principles, which was rendered 

 abortive by its failing to combine sufficiently the various interests, and drew there- 

 from the conclusions : — 



1st. That' such works should be undertaken on a financial basis which will 

 secure their completion, and 



2nd. That the taxable area should be as extensive as possible. 



II. Rivers not tidal. He denied that fresh-water rivers could be compared 

 ■with tidal rivers, and instanced the difference between the floods of the Tiber and 

 the Thames. 



He illustrated the present condition of the fresh-water portions of our rivers by 

 details of the Upper Nene, where the ratio of flood to dry weather flow was 430 

 to 1; of the Cray and Darent (tributaries of the Thames), where the flow was in 

 the former nearly uniform, and in the latter the ratio of flood to drought was 16 to 1, 

 thus showing the different treatment required in each case ; and after giving reasons 

 for stating that, in the absence of a comprehensive conservancy, the jealousy of 

 the mill-owners and other riparian proprietors had led on the Nene to a scramble 

 for fresh water, and on the Cray to the use of excellent water chiefly as a carrier 

 of refuse ; and that the Darent presented a unique example of a valley in which 

 the watershed had been adopted as the boundary of the rateable area, he classed 

 the several functions of a stream passing through a highly civilised community 

 (though the order of merit varied) as — 1st, water-power ; 2nd, water supply ; 3rd, 

 carriage of refuse ; 4th, navigation ; 5th, purity equal to at least the preservation 

 of fish, and stated that each of them was now guarded independently and without 

 any comprehensive plan or control. His general conclusions were : 



1st. That each river or tributary must be treated as a whole within the boundary 

 of its watershed. 



2nd. That all public works within the watershed should be under one undivided 

 control. 



3rd. That the rateable area for these purposes should be conterminous with 

 the watershed. 



4th. That the minimum flow of streams liable to floods should be increased by 

 storage. 



5th. That the separation of good from foul water, the collection and distribu- 

 tion of wholesome water, the discharge of sewage, the improvement of the channel 

 both for conserving the dry weather flow and for dispersion of floods, the main- 

 tenance and improvement of tidal reservoirs and navigable channels, the removal 



* This paper was published in extent in ' Engineering,.' November, 1878. 



