ASHBURTON COUNTY WATER SUPPLY.

Lyttelton Times, Volume LVII, Issue 6509, 6 January 1882, Page 6

ASHBURTON COUNTY WATER SUPPLY.

Up to this data we hare published everything bearing upon the subjtct of irrigation in connection with the Ashburton and Bakaia Plains—a sobeme for which was pluokilj initiated some time ago by the Asnburton County Counoil. As our columns thus far afford a history of perhaps as important a scheme as has yet been undertaken by any public body in the Colony—a work thaC has, to a great extent, changed for the bettor the whole face of Nature in a wide district—we feel that the chain would be incomplete were we not to publish the following report by the County Engineer read to the Asnburton County Council at its last meeting, on Wednesday:— "Ashburton and Bakaia Plains Water Supply.—The contractors for the B line of water-race at Bakaia are making satisfactory progress with the work, and already the earthwork is completed to the extent of about fifteen miles, or about two-thirds of the entire length authorised by the Council. The amount of absorption to the E channel has not decreased materially during the month, and it is only within the last ten days that the flow of water reached the lower end of channel at T. Harrison's, and that after the capaoity of flume over Dry Creek has been increased, and an additional supply let in at upper end. There is still a small surplus available from Pudding Hill, but whether it will be sufficient to supply the numerous forked channels now in construction below the railway is, I think, somewhat doubt, ful, especially as the greatest amount of percolation has hitherto taken place in the district eitua ed between the railway and the sea. The contractor for the extensions of the D and E lines is making good Ei-ogress, and since last meeting of Council as got upwards of 20 miles finished. The works on the D 1 line are also well forward, fully twelve miles having been completed during the month. The contractor is about to stan on the D 2 line, and the culverts and other necessary works are so far advanced on the subsidiary lines and extension channels between Ashburton and Bakaia rivers, that there is every prospect of these being available for service about the beginning of next month. In lieu of the auxiliary servioa which was proposed, from the creeks in Mount Hutt district, and which latter I reported on at last meeting, I have, as requested by the Counoil, carefully examined iuto the question of a source of supply from the bed of the North Ashburton river, about two miles below the Pudding Hill Bridge. I am of opinion that a supply, whioh might probably prove adequate, could be obtained by filtration from the under current in the river bed, at a point a short distance below the inlet of Messrs Gould and Cameron's private waterrace. Here the water seems to rise to a level of about four feet beneath the general surface, and I calculate that by linking a channel or channels, in all about 20 chains in length, with a maximum depth of seven feet, that a good flow might be seoured. This flow, however, would no doubt be Gomewhat variable, and the results could only be accurately ascertained after experiment. An expenditure of about £7O or £BO would probably cover the expense of all the work which would be neoessary in the river bed, and if an ample supply were obtained, there would be no difficulty.in leading it over the terrace of the river there, which is only a few feet in height. For augmenting the service from Pudding Hill, I would suggest that the race should take the general course narked on the plan, so as to effect a junction with the existing races at Methven. A considerable stretch of fluming would be required over old gullies, but these are unavoidable. The expense would be approximately as follows-.—Works in river bud, say £80; 4 miles main channel, £100; fluming gullies, road culverts, &0., £200; total, £3BO j say £4OO. This is on the assumption that a free right-of-way for said race will bo granted to the Counoil as in all other oases, and as tbe Eropertiea through whioh it would pass would a benefited thereby, I presume there is no reason to doubt that the right-of-way would be readily granted. From the same source the district referred to in the petition by Messrs Power, Devery, and others, could be supplied by a small race, nine miles in length, on the route indicated by dotted blue line on plan. Tbe expense of the latter should not exoeed £IOO, in the proportion of about £4O for earthwork and £6O for fords, &o. I am sorry to have to report that there has been a good deal of tampering with the different raoee lately, the effect of whioh has been to give a very uncertain and intermitting supply. For instance, at Mr Harrison's, on the H line about three miles above Hatfield, the waterrace had been obstructed and destroyed by J lacing bags of clay in the raoe. At Mr ohn Harrison's below Hatfield also, the raoe was diverted and thrown on to the fields. Again, ut Dollaraore's, on the Chertsey race, damage was caused, tbe raoe having been ploughed in with a double-furrow plough, and a large proportion o£ the water diverted for private ends. In some instances alio, on Mr Hart's and Mr Holmes' properties, the parties cropping the land had dammed up the race with sods, for the purpose of forming drinking plaoes, and i temporarily diverting the water from its proper course. Another cause of damage and loss of water is

due to several of the owner* having failed to provide the necessary field oroppine* on the races. In connection with the < subject, the qnettion of pollution bone which require* to be carefully guarded against, as there has been more then one case recently or a dead animal having been found in the races, «'Ashburton-Hangitata Water Supply.— The different contract! for this district are progressing favourably, and several of the line* nre already finished, but cannot of course be supplied till the flumes are erected over both branches of the Hind* river. The contractors for the fiumes had made prepara* tiona for starting the woik, when, unfortunately, some waggon loads of the timber they ! had provided were burnt down by tussock I fires at the present terminal station of the Mount Homers branch line. This, however, i will not delay the work more than a day or two, and aa these flume* form the key of the system for the opening of the Hinds-Bang!-lata service, no time will be lost in starting the pile-driving and pushing on the work during the harvest. Between the Ashburton and Bangitota rivers there has been constructed a length of 98 miles of water-races, aa alto most of the culverts and fords and all the concrete tanks over that length. " Winslow and Willoughby Water Supply. —As rcquosted by the Council, I have gone over the district between Winslow and Willoughby, and after a careful investigation | would suggest the routo as laid down on the accompanying plan. The dotted blue lino I shows the proposed extension of one of the | linos from the Westerfield district, but the ground ovor that district is so porous, that a ! large quantity of water will have to be let in to charge the rac«s thoroughly, such a quanI titr indeed as may be liable to damage the i races in some places, and instead of throwing still more water into the upper sections of theso races, I would beg to suggest for the supply of the proposed extension below Winslow the forming of a oonneotion with the adjoining creek, at indicated by red line on plan. As this oreek gradually increases in volume from this point, downwards through the •wamp ground, it appears to me that no damage could possibly accrue to any interest by utilising it, and, so far as I can learn, all the owners in the district wish it to subserve the public good. " Mount Some? Water Supply.—The first contract for this work is in progress, and two miles fifty-two chains of the main channel has been completed. I have obtained the necessary data for arranging the head works, flumes, &c, at the proposed source of supply. "Wakanui Water Supply.—At.a recent meeting of the ratepayers interested in this scheme, a few alterations and extensions were proposed by owners. These are shown on the accompanying plans, and if the Coanoil should approve of them, the work could be commenced as soon as the Council may determine. The difference in cost which the altered lines would entail would scarcely be appreciable, and I anticipate that the whole work can still be carried out for the original estimate of £875, provided the contracts are not let during the month of harvest. The ratepayers are almost unanimous in asking for the races in this district to be carried along the lines of roads. There is one phase of the question especially, which should be fully considered at the present stage, namely, the more minute distribution which some of the owners expect to be effected as soon as the races are finished, by leading water from the mains to almost every paddock, large and small, within the district. The sizes of mains would in a great measure depend on the system (if any) which may ultimately be adopted for further distributing the supply, inasmuch as in many instances the small branch races would be led in Buoh directions as not to bo returnable to the mains. Indeed it would be safe to assume that no part of the supply led out in this way would bo returned, and tbe sizes of mains would have to be adjusted accordingly. Some of the owners seemed to be of opinion that they themselves might be allowed to draw off the water from the mains under a system of mutual arrangement with one another, but I should consider it imperative, in the general interests of 'the scheme, that at least the mains and the connections therewith should be immediately under the control of the Council. I may state, however, that the estimate does not include anything beyond the cost of head-works and mains along the road sides, without reference to the field distribution referred to."