142 Transactions. 



tliere is but little progress to record with regard to arterial drainage. Witli 

 the exception of the Eangiora Swamp, (which has been partially reclaimed 

 by a carefully planned system of drains, calculated, when completed, to 

 reclaim 7,000 acres of swamp land), the drainage works of the province are 

 of no interest, in a scientific point of view, except as showing the mischief 

 that may be done by attempting to drain extensive districts without keeping 

 distinct outfalls for the upland and lowland waters. 



I would wish to direct the attention of the members to the efforts being 

 made in England to enable landowners to obtain powers for draining 

 through private properties, and for the relief of districts which have been 

 water-logged, to use an expressive term, by the injudicious erection of dams 

 and weirs for obtaining mill power, often to the infliction of great injury 

 upon the surrounding properties. 



Such legislation is no less needed here than in England ; and I may 

 remark upon a peculiar feature of our low-lying lands, which introduces 

 unusual diificulty into the question of main drainage. 



It is, that the natural watercourses through the swamps and half-dry 

 lagoons are in most cases above the level of the adjoining land, running 

 between embankments which appear to have been formed by the gradual 

 deposition of silt in comparatively still Avater. So generally is this the case, 

 that in the neighbourhood of Christchurch it will almost always be found 

 that a rise in the ground marks the position of an old watercourse, the 

 original source of which has been cut off by the gradual deepening of the 

 beds of the rivers by which it was fed. 



It will, therefore, be readily understood that the natural watercourses 

 cannot be used for the drainage of our swamp lands, but that new lines 

 must be cut for that purpose ; and it is precisely the interference with 

 private property involved in this course, that has led to so much difficulty 

 and litigation in the attempts to reclaim the swamp lands in the province. 



For some years past the Provincial Engineer has been engaged in record- 

 ing the levels of the country, as ascertained during the progress of the 

 various road and railway surveys, the several sections having been all taken 

 with reference to a common datum, viz., ordinary high- water springs at 

 Sumner Bar. It is proposed gradually to extend these levels over the whole 

 province, as opportunity offers, and to establish permanent stone bench- 

 marks in every road district, for future reference. It is interesting to 

 observe that a similar work is now in progress in Erance, for the purpose 

 of affording accurate data for engineering surveys of all kinds, and it would 

 be difficult to overrate the value of the information thus given to the public, 

 or the facilities it affords for ascertaining, almost at a glance, the difference 

 of level between distant points which it is required to connect for the pur- 



