478 FOURTH REPORT — 1834. 



The principles of drainage recommended by Mr. Rennie were, 



1st, To shorten and deepen the courses of the existing rivers ; 



2nd, To form new cuts or drains in different directions 

 through the fens, with inclinations in their beds of from three 

 to five inches ; 



3rd, To form a catch-water drain round the bases of the hills 

 skirting the fens, and to conduct the upland waters by an in- 

 clined bed of six inches per mile, through a separate outlet, into 

 the head of the proposed Eau Brink Cut, into which all the drain- 

 age-waters were to be carried likewise. 



The expense of completing this magnificent drainage was 

 estimated at £1,188,189. 



The Eau Brink Cut was originally projected by Mr. Nathaniel 

 Kinderley in the year 1720: the object was to conduct the waters 

 of the river Ouse by a direct cut across the marshes from Eau 

 Brink to Lynn, of about two miles and half in length, instead of 

 allowing them to flow by the old circuitous channel of upward 

 of five miles in length. 



This Cut was completed, agreeably to Captain Huddart and 

 Mr. Mylne's award, under the direction of Mr. Rennie, in the 

 year 1825. 



In December, 1821, the tide rose on the average eleven feet 

 ten inches on the cill of Old Denver Sluice ; while at low water 

 the average depth on the cill was 9*6 inches, and the average 

 height of the water in the river was ir5 inches. 



Since the completion of the Eau Brink Cut, in the year 1825, 

 the residts have been. 



That the low-water mark has fallen six feet lower than it 

 formerly stood at Denver Sluice, and from eight to nine feet at 

 Eau Brink. 



That the spring tides now rise at Denver Sluice thirteen feet, 

 and neap tides eight feet. 



That the river has deepened between Denver Sluice and Eau 

 Brink ten feet upon the average, and its general sectional area 

 has increased from one fourth to one third. 



That the low-water mark in Lynn harbour has fallen four 

 feet, and the navigable channel in Lynn harbour has deepened 

 seven feet ; and that where there were formerly twelve feet in 

 depth of water in the intercepted bed of the old Ouse between 

 Eau Brink and Lynn, there is now a tract of 900 acres of land 

 under cultivation, all of which has been effected by the process 

 of warping. 



The tide in the Eau Brink flows three hours, and rises in that 

 time fifteen feet, thus leaving nine hours of ebb. 



