300 



the new channel, and for some time the south channel was generally used by 

 vessels, and their cargoes had to be ti'anshipped by boats from the vessels 

 lying in the lagoon to the wharf, which they reached by going round outside 

 the middle bank, there being an available channel there for boats within the 

 break. During the whole of this time, a long spit tailing out to sea from the 

 end of the old south spit, which had formed a protection against a southerly 

 sea, was being driven in, until eventually, in August, 1867, it overlapped the 

 middle bank as much as eighteen chains in lengtli, and very shortly afterwards 

 was driven home on to it. I may remark, that the old south channel remained 

 deep and workable for vessels until within a short time of its closing up, 

 although, except in floods, when a small quantity of the river water came 

 down the south river channel through the lagoon, the only water finding its 

 way to the sea by this channel was supi)lied by a few small creeks, and the 

 tidal water which flowed in and out of the lagoon. 



In October, 1867, serious troiible befell the inhabitants of the west side of 

 Revell-street ; the sea encroached so fast on the beach at the rear of the 

 houses on that side of the street as to threaten their destruction. I believe 

 this to have been principally caused by the set of the current, induced by the 

 action of the river current and the sea together, aggravated by particularly 

 high tides and strong westerly winds. The efliect of the action of the water was 

 to carry away the sand and gravel to a depth of 6 or 7 feet, depositing it again 

 either northwards or southwards, as the current happened to tend, leaving a 

 perpendicular face of 6 or 7 feet, in some cases even more, which every 

 successive tide pushed inwards considerably. 



To oppose this I tried groins formed with timber caissons, filled with 

 gravel, each 20 feet in length and 12 feet wide in the bottom, the sides having 

 a batter of one to one ; these caissons were simply laid on the sand end to end, 

 running out perpendicularly to the beach line, each groin being about 120 feet 

 long and 5 feet high, the outer ends having the same batter as the sides. The 

 first one was put down on October 26, 1867, and four more during the last 

 three days of November ; each groin was completed in a single ebb tide. They 

 were placed about three chains apart, with two tiers of fascines sunk in the 

 sand, stretching across from groin to groin at the inshore end, a space of about 

 15 feet being left between the tiers. The good efiect produced by these groins 

 was at once apparent, the heavy seas being broken, and a tendency to deposit 

 instead of scouring induced. The drawing (No. 5), shows another action of 

 the river at the part protected by these groins. During the dry weather, when 

 the river was low and south-west winds prevailed, the south spit was driven 

 up northwards until it overlapped the north spit more than forty chains, and 

 drove the river against the l)each, until serious fears v/ere entertained for the 

 houses on the west side of Kevell-street ; the river channel being reduced by 

 the washing in of the south spit, cut in deeply on the beach, which it under- 



