A Day in the Swamp

Evening Post, Volume CX, Issue 110, 5 November 1925, Page 16

A Day in the Swamp

Draining the Makerua

To moat people, perhaps, the great swamp area along the Main Trunk line between about Koputuroa and Linton will seem a sort of dreary wilderness to turn away from as the train rushes past, an ugly, depreraing. landscape without redeeming features. To a. few, like the present writer, it appealsi with the rare prospect—in New Zealand —of a vast expanse of plain still in an almost primeval . state, stretching out to far-distant horizons, the nearest approach we have in the Dominion to show to the limitless American prairie spread like an ocean each clde of the rail as you cro3B the continent. ■ . Few people go into the. great swamp. Boads shrink away from it and run in to the shelter of the hills, twisting and turning and climbing and dropping, in a devious route to the capital of the plains, Pahnerston North. The railway skirts it heedlessly, crossing a bay or two, where the swamp flows in like an inland sea towards the foothills. There is no ; main road across the swamp, and only a few side roads running into it for a short distance. ■ It was therefore a pleasure for the writer to be personally conducted into this strange region of tall flax and toi-toi and raupo with its, deep drains and hidden streams, invisible till you come on to them. It would take more than a day to see the swamp, on foot or horseback; so the great time-saver of the ■ farmer—the Ford—was called into action and to'pk a party of three into all sorts of places where roads .were tracks and full of bogholes and quagmires at that. Truly, a ship of the swamp. THE PLAN AND THE METHOD The idea was to see for oneself what the Makerua Drainage Board has been doing for the past four or five years tdwardß draining the swamp and protecting an area of some 22,000 acres, as far aa possible, from inundation by the Manawatu Kiver, which makes it, of course, a matter of interest and a factor in the. larger scheme for the control of the river, outlined elsewhere. Travellers in'the train will, doubtless, have noticed, as they passed, the puffing of steam from a low structure among the flax in different places,at different times with the. rising of an arm "above the surface: to swing, round and deposit something from a buc-i ket on the bank—indicating, at a glance, the operation of a dredge. At places one sees quite a wide canal dug out with high banks and a mile or two of a stretch be-! fore it merges in the mass of flax swamp. These are bits of quite a large work carried out by the Drainage Board, at quite a large cost also, over £100,000, one. is; told, which is nothing to be sneezed, at. It is only by degrees that one picks up the plan of it all, Here is what is known as a drag-line dredge scooping up towards itself buckets full of the lower soil of the swamp, rich silt, a stratum of peat, with timber in it, and below it a sort of blue loam resembling papa in" the making. The dredge is working alongside a sluggish", tired-looking river, which one is astonished to be told is the- Tokomaru, the brisk mountain stream one last saw up in the hills behind Shannon, contributing some of its Water to the Arapeti Reservoir, 1250 feet above sea level, j to be run through the dividing ridge in a tunnel and down a spur in big pipes to the Mangahao hydro-electric powerhouse, there to make electricity for Wei' lington. This is what bustling mountain torrents come to when they venture out into low plains. They cease to act .as drainage channels and spill their weary ; waters over the land, making it a swamp. The Drainage.Board has to make something of a river of the Tokomaru again to get rid of the water. This is how they do it. The dragline moves on caterpillar tracks scooping out a channel oil each side of the main ; parent river, depositing the spoil on high stopbanks to make levees, as they call them after the famous bank works on the Lower Mississippi. Thus' you have a river in triplicate, as it were, a central channel and two side courses, all three between artificial banks. This gives ample room for flood waters, whether coming down from the'hills or backing up from the Manawatu. A few floods and the thin partitions between the three streams melt away and the river becomes one again. Between banks it will now be 200 feet wide ancj.may run to 20 feet in depth .before it^hs over the banks— quite a decent waterway, this. The banking has been carried out for nine mile? on each side, eighteen miles in all—quite a decent bit of work. • A YVQrTK OF MAGNITUDE When your genial informant tops your marvelling by telling you that the board has built 48 loilas of. similar lavees altogether, you .begin to realise that this is a work of magnitude. The *cheme unfolds itself. The area of the Makerua is about 22,000 acres, and all this" was as subject to flood as any part of the Mauawatu lowlands. When the "yellowleaf" complaint threatened to wipe out the flax business, root and blade, and the future -looked a bit blank, some of the enterprising spirits came to the conclusion that the only thing to do was to drain the swamp so thoroughly and protect it so well from floods that it could be turned into grazing land and farms, if need be. One of the moving spirits was Mr. Hugh Akers, who owns a stretch of land flanking the Manawatu for a good many miles. A few years ago it was heavy flax; then it vyas hit hard by "yellow-leaf"; to-day it is one of the most beautiful tracts of grassland one could see anywhere on earth. The soil is pure silt many feet deep, which explains. A poll of the ratepayers—there are 42 of them—was taken in 1920 and passed authority to raise a loan of £100,000 to drain the,swamp, on a plan furnished by Messrs. Jickell and Gilmour, of Pa.lmereton North, the well-known _ civil . engineers. The money was obtained and the plant—a drag-line dredge and a floating steam shovel —procured. The plant is American, because Britain could not guarantee delivery in time. The work has been going on' steadily ever since. The gist of the schema is: (1) To wall out the rivers than in the past have overflowed into the Makerua. These are the Manawatu, from Linton down to whore the Mnngaoro runs in somewhere neai' the boundary of Shannon Borough, and the Tokomaru. The levee constructed by the board on the Makerua side of the Manawatu is'l6 miles long. Levees have also been built along the Mangiiore stream, which carries the tailrace of the

Miniature River Scheme

To Lower Surface Water Level

hydro-electric power-house, the ■ Tokomaru and side streams. Thus the Kanawatu and its tributaries are preventing from inundating the Makerua except under abnormal conditions, which will only bo swept away when the full Manawatu Biver scheme is carried out. • ■•. (2) Another main drain has been cut some 4$ miles long to/take into the Tokomaru all the minor drains over a certain area. The original main drain, cut in 1907 by the drainage board, extending over seven miles, has been materially widened and deepened. All minor drains have been or will have to be'lowered accordingly with a view to reducing the Waterlevel on the swamp area six feet below, what it is now, ■■''"■- The whole work is steadily approaching completion, and this cummer should probably see it but. -So far it has been eminently successful, and there is every prospect of the Makerua' being made dry enough to be converted into ordinary, jfraaing land, if necessary, for backing up into the drains is prevented'by the employment of flood gates where the drains debouch into the streams already mentioned. It is generally conceded that this valuable work in the Makerua would be perfectly safeguarded by the adoption of the main river scheme and Mr. Akers, who is a member of both bodies, is a strong advocate of the 1 river control project. The members of the Makerua Drainage Board are:—Messrs. Joseph; Liggins (chairman), H. J. Tv Hume, A. Seifert, H. Akers, E. L. Tipple.", v