Shingle on the East Coasts of New Zealand. 55 



having kept back the shingle some four years or more, it is 

 hoped that it will do so always. They do not ask what 

 becomes of the shingle, or what will become of it in course 

 of time. The action at Napier, which will be mentioned 

 presently, may prove instructive in connection with this 

 matter. (See pars. 13 and 14.) 



9. Another result of the construction of the breakwater 

 at Timaru may be mentioned to show that travelling shingle 

 cannot always be obstructed without some evil following. 

 When the shingle was stopped by the breakwater the beach 

 in the bay in front of Timaru was entirely denuded, and 

 a serious erosion of the banks commenced. Very heavy 

 expenditure has been incurred in throwing down large blocks 

 of stone along the shore to protect the railway from being 

 destroyed. It was at one time even proposed that the break- 

 water should be cut through to allow of shingle passing as 

 before. This was not done. The denuding of this beach 

 occurred before the breakwater had been carried out far 

 enough to shelter the beach from the action of south-easterly 

 seas, although it was sufficient to keep back shingle coming 

 up the coast from the south. The bay is now more sheltered, 

 and will become more and more so as the breakwater is 

 carried further out. The northern part of the bay is, how- 

 ever, exposed to seas from the east and north-east, which must 

 carry shingle down the coast, contrary to the general direction. 

 There is shingle less than 1J miles up the coast, in front of 

 the Waitarakao lagoon. Some of the shingle so carried 

 down the coast is likely to come under the shelter of the 

 breakwater, so that it will not be carried up the coast again 

 by south-easterly seas. Shingle will, then begin once more 

 to accumulate in front of the town as at Oamaru. This 

 result may already have commenced, although possibly 

 there is too little shingle to have attracted notice as yet. 



10. Between Timaru and Banks' Peninsula there are 

 several rivers, against four of which it is noted on the chart, 

 " Mouth always open ;" the others are probably closed except 

 during freshets. The author does not know whether these 

 rivers bring down further supplies of shingle or not; probably 

 they do, for the whole of this part of the country is said to 

 have a substratum of shingle. The beach is, however, con- 

 tinuous up to Banks' Peninsula. The last twelve or thirteen 

 miles, in front of the Waihora Lake (also called Lake 

 Ellesmere), is really a broad neck of shingle, in some places 

 nearlv a mile in width. This encloses a large sheet of water, 



