WAIMAKARIRI OVERFLOW.

Globe, Volume XXII, Issue 1861, 10 February 1880, Page 3

WAIMAKARIRI OVERFLOW.

An adjourned meeting of tho delegates of ihe various local governing bodies interested :u the question of tho overflow of the Wainakariri on its north bank was held at the Euiapoi Council Chamber on Monday afternoon. Present—Mr Blackwell, Mayor, prodding, Mr Isaac Wilson as chairman of the Eyreton Road Board, and Mr H. Blackett as representing the Mandeville and Rangiora drainage district. The Chairman read the report of E. Dobson and Son in connection with the map laid on she table. After referring to an unavoidable delay in its preparation, the report stated Shat the levels had been obtained by a careful mrvey, and the map compiled from plans in she Survey office, which served to remind them thob it was desirable that a complete hydrographical survey should be made by Government of the former and existing channels as a basis for designing works for training the river into a permanent channel. Mr Dobson went on to say: —“7th. I am asked in reference to the protcctiveworks erected by tho Board of Conservators for tho South Waimakariri District—(a ) To what extent have the said obstructions been erected within the original river course ? —ln several places, as notably at the points marked on tho map, the concrete work extends many chains into tho existing river bed. (b.) What is (or is likely to be) the effect of such works on the north side of the river, including Kaiapoi town F—The effect has been to the present time to throw the water towards the north bank, which in consequence has been more or less carried away from the end of Fairweather road, near the south-west corner of R.B. 17421, for a distance of about nine miles up stream, a considerable acreage being thus destroyed, whi’at a portion of the river adjoining tho north bank, in some places half a mile in width, which for many years has been dry land, is now the bed of the main stream. The future effect (in addition to the gradual encroachment on the north bank) to bo specially guarded against, is that the river may find its way along the low ground in the line of Fairwoather’s road, and form a permanent channel into the north branch, which, in the event of the new stream through the island becoming choked with shingle above the level of the entrance of the old channel, would have again, as formerly, to carry the great bulk of the river, with the result that the town of Kaiapoi would suffer severely from floods with every heavy fresh, (c.) What steps would you recommend to be taken to counteract the effect of these works, and of what nature?—First, to establish a permanent channel for the river, from the head of the Kaiapoi Island to the sea, which should discharge into tidal water below the town of Kaiapoi. Second, to protect the low ground near Fairweather’s road by embankments, to prevent the formation of a new channel leading into the north branch. Third, to establish a system of groins along the north bank of the river above Kaiapoi Island, to check the scour and protect the land from further loss. Of the engineering questions which the subject embraced, the first in importance was, he 1 said, the formation of a permanent channel from the head of Kaiapoi Island to tho sea. To provide such an area of escape for the flood water that the banks should not be overflowed, and would only require protection from the scour in the channel itself. Recapitulating the recommendations, the report said : —Briefly, then, to recapitulate the above recommendations, I would point out—lst. That the protective embankments between Haar’s and Fairweather’s roads are works of immediate necessity, and should be put in hand without an hour’s delay. 2nd. That the protection of the north bank above Haar’s road is very desirable, in order to prevent further less of land, but that unless additional works were erected on the south bank so as greatly to reduce the area now existing for the passage of tho floodwater (as would be the case, for example, if the channel between M’Lean’s Island and the mainland wore to be closed up), there is no probability of the river breaking through the bank and forming a new channel. 3rd. That the future safety of the town of Kaiapoi and of the eastern portion of the Eyreton district depends on the establishment of a permanent direct channel which shall deliver the whole of the Waimakariri water into the estuary below the town of Kaiapoi, leaving the Kaiapoi river to take only the water from the Eyre, the Ohoka, the Oust, and the Cam, the outfalls of which should be deepened and widened to give a more rapid discharge for flood water. Lastly, I may observe that whilst the protective works near Driscoll’s road and the groins about Haar’s road may be considered as local works, to be undertaken by the Eyreton Road Board ; the works connected with the establishment of a permanent channel, which involve important questions of compensation and of legal rights, can only be dealt with by a specially constituted body, invested with the legal powers to raise the requisite amount, to take all land that may he required for the work, and to pay such compensation as may be justly due to those whose property is affected thereby.” Mr Wilson thought the only place which needed immediate attention was at the point near Eyreton, where an embankment ought, to be erected and willows planted in rows. The Eyreton Road Board had decided to do this work, which was, however, at present in abeyance. Mr Blackett entirely agreed with the recommendation that the river ought to be placed under the management of one Board of Conservators, who should exercise control over tho lands on both south and north sides. After some discussion it was res.lved—- “ That the map and plan be forwarded to the Eyreton Road Board, and attention drawn to the reference to the embankment at Haar's and Fairweather’s roads.” “ That the South Waimakariri Board of Conservators be informed that in consequence of the erection by them of obstructions within the original river, considerable damage has resulted to the district on the north bank, and the Board be respectfully requested to erect no fur her obstructions.” “That the Government be written to, and requested to open up the channel through Stewart’s Gully, in order to relieve the district from the present disastrous effects of flood-water. That a copy of the report and minutes bo transmitted to each local body interested.” A vote of thanks to the chairman, moved by Mr Blackett, seconded by Mr Wilson, was then passed.