MANAWATU-OROUA RIVER BOARD

Manawatu Herald, Volume XLVIII, Issue 3647, 4 June 1927, Page 3

MANAWATU-OROUA RIVER BOARD

NEW SCHEME BROUGHT FORWARD.

SECTIONAL WORK TO COST £200,000.

Proposals for a, new Hood protection scheme were considered at a meeting of the Manawatu-Oroua River Board this week, over which the chairman, Mr W. S. Carter, presided, and in the discussion which ensued full details were gone over. The chairman intimated that, of course, the board could make no decision in the matter that day. The new proposals brought forward were to be regarded as a basis on which to work, and the question of sectional work was to be considered. If sectional work was undertaken, he took it that the areas of the board’s district concerned wo-uld-be rated'as each section was proceeded with. DETAILED SCHEME.

Mr. Hay stated that as instructed by the. board he had made investigation i|nto matter of modifying the comprehensive scheme with the object of enabling the board to consider the question of doing the work by stages.' The principles on which he had worked were: —(1) Each section of the work to be part of the comprehensive scheme. (2) The work proposed was that which would give the est results for minimum expenditure. (3) Each portion of the River Board’s district would give the best results for miniimprovement to take precedence over banking. Job 1, Rush Flat, navigable channel, 50 feet wide, twelve feet deep and 57 chains long; quantity of excavation, 100,000 yardSi Work to be done by dipper dredge, suction dredge, or by land excavation. Estimated cost, £5,000. The purpose ox this work was primarily (1) to give a better route for shipping to Foxton; (2) secondarily, to assist in the scouring out of the new channels proposed through MauawatuIvuku and Mouton. By the adoption of certain methods in job 2, the first necessity for the navigable channel through Rush Flat might be obviated —the secondary object of the channel being to assist in the scouring out of the new channels proposed above it was not of sufficient importance to justify this work.

Job 2, Manawatu-Kuku cut, sli chains long, 40 feet wide, by 35 feet deep; total excavation, 450,000 yards; work to be done by suction dredge, and to cost £20,000. This amount allowed for any compensation that might have to be paid for severance of the native land through which the cut would be made. This cut joined the Manawatu River on the west opposite Kush Flat, and on the east at a point half a mile north of the outlet of the Mouton drain, cutting oil nearly four miles of the river. Its purpose was to take flood waters from the Mouton quickly, and to enable the Mouton main cut to scour out. If land machines were used there would be no necessity to use the channel of the river for the dumping of the spoil, and the necessity for Rush Flat for navigation would be obviated. '

Job 3, main cut, from the Manawatu near Poplar mill, through the Moutoa, joining the Manawatu again about one and a-half miles above Foxton wharf. It was six miles 41 chains long, and 22± miles of river; estimated cost £130,000. 'i lie work consisted of building stop banks, cutting a central channel from the Manawatu River at the lower end to the Karikari drain —a distance of live miles —the building of two low-level bridges, the construction of eleven flood gates and adjustment to the Moutoa drainage, protective works, fencing, and planting. During the construction of the central channel, the water for flotation would have to be let into the channel through temporary gates on the banks of the river, and be controlled so that there would be no interference with the present drainage of Moutoa. As regards the low-level bridge on the main road over the central channel, this was all the River Board could be expected to do. Although traffic would still be blocked during flood time, the flood waters would run off more quickly, and in that respect the users of the road would benefit. As regards drainage, the cutting of the central channel up to the Karikari would very considerably improve the drainage of Moutoa —at least four feet better. Langley’s north and south and the Diagonal would benefit in the same degree, and by taking advantage of the floodgates proposed under this scheme the land lying between the river and the cut* below the Diagonal would be very much improved as regards drainage. This job was essential for the flood protection of the district. By doing it, all Moutoa, Koputaroa, and Makerua would receive immediate benefit, while Kairanga and Oroua would be able ‘to get rid of flood waters more quickly even if no further work were done.

Job 3. —It would be noticed, continued Mr. Hay, that the central channel was considered in the estimates as being taken only as far as the Karikari. The reasons were first to obviate the necessity of putting a bridge on the Shannon road, and, secondly to prevent too great a scour taking place with risk of setting up the lower portion of the Main Cut. Another feature of the proposal was that it connected, for several reasons, with the Manawatn on the Foxton side of Poplar Mill, and that the stopbank on the east side of the cut bent round to

j6in the existing stopbanks at the back of New til’s. Job 4, Opoi spillway; 50 chains long and cutting oc 3J miles of river; estimated cost £15,000. This work to provide a tlood spillway from Opoi bend to the Manawatu River just above Poplar Mill. It was not proposed to make this cut at present, as it would not be safe to do so until the main cut was sufficiently developed. This job was to direct benefit to Makerua and less directly of benefit to Kairanga and Oroua subdivisions. Job 5, tributary channel, estimated cost £ISOOO. For the purpose of taking ultimately the drainage from Makerua and Koputaroa subdivisions and the Koputaroa Rivers. Its immediate purpose was to relieve the flow in the main river below Paiaka and to act -as a scouring agent on the lower portion of the main cut. It would not he necessary to cut a .central channel at once, but merely to build stopbanks and lower the river bank so that small freshes would come down the tributary channel. An alternative scheme would increase the estimate to £IB.OOO. Job fi, stopbanking Manawatu River from mouth of cut to Foxton, distance 70 chains, taking 14,000 cubic yards, estimated cost £9OO. This work was necessitated because of the raising of the water level at the mouth of the main cut, which would happen until the ManawatuKuku cut was scoured out. Job 7, stop-banking the right bank of the Manawatu from the end of the main cut upstream to Connolly’s camp. This work was required in any case for the protection of Moutoa from small floods, and would take about 48,000 cubic yds. Material, estimated cost, £3,000. Job 8, deepening Koputaroa and stop-banking. Work of benefit to Koputaroa subdivision; estimated cost £3,000. Job 9, cutting off bend in Manawalu opposite Koputaroa River; 8 chains; estimated cost, £2OO. Land severed by cut, estimated, £9OO. Principal benefit to Koputaroa, but also some to Makerua. Job 10, cutting off double bond of Manawatu near Moutoa hall; total length of cuts 30 chains, stopbanks on Makerua side 17 chains; estimate £3,000. Benefitting Makerua and Moutoa subdivisions. Jobs 1 to 10, comprising the work in tlia lower section of Manawafu; total estimate, £190,000. Job 11, Paki’s Point, cutting a channel across narrow neck of land estimate, £32,000. Job 12, Aker's Cut, cutting across narrow neck of land at Page’s Point, above Miss Edwards's farm; estimate, £I,OOO. Job 13, Constructing stop-bank about three feet high round bight in river at end and north of Tiakitahnna Road, taking about 4000 cubic yards estimate £3OO. These three jobs would lie of direct benefit to Kairanga, and their total cost was £SIOO. OROUA RIVER. Job 14. —Cut diverting Oroua River from bend below Rangiotu bridge into Manawatu River below Russell’s house, about 10 chains below outlet of Burke's drain; length, 30 chains, cutting off 2.1 miles of Oroua River; estimate, £4200. Benefiting Oroua and Kairanga subdivisions. Job 15. —Straightening bonds in Oroua River. The course of the Oroua River was particularly tortuous over a, length of one mile situated some distance above Mangawhata. The job consisted of straightening and reducing the length of the river from one mile to half a mile. The estimate of £750 did not provide for the purchase of land, as the land affected was entirely between stopbanks, and various severances would counterbalance each other, so that little land, if any, would be.taken off the titles. Total length, 36 chains. Job 16. —An alternative to Job 14, but not of such benefit. Consisted in stopbanking Oroua on left side from Rangiotu to junction with Manawatu. About 20,000 cubic yards of earthworks necessary; estimate, £I2OO. Benefiting Lower Kairanga. Job 17. —Erecting stop-banks from Rangiotu to above Mangawhata and joining up with Job 15. Total quantity earthworks, 60,000; estimate, £3OOO. Benefiting Oroua and Kairanga. Job 18. —Constructing floodgate at mouth of main drain of Sluggish River Drainage Board's district; estimate, £I2OO, with provision for access road over Benefit to Oroua subdivision. Jobs 14, 15, 17, and 18.—These four jobs-Jobs 14 and 16 being considered as alternative—total £9150, if No. 14 is undertaken, or £6150 if No. 16 is done instead of No. 14- They directly benefit Kairanga and Oroua subdivisions. Summary. —Omitting Jobs 1_ and 16, the total cost would be £205,250 made up as follows: —Land, £66,925; earthworks, £121,970: bridges, £2900; floodgates and drainage, £8800; fencing, £2575; planting and protective belt, £2OBO.