Ohinemuri Regional History Journal 21, June 1977


Large scale drainage of the Hauraki Plains was commenced in 1908, a special act being passed to enable the Government to raise funds and reclaim the area. It included some 90,000 acres situated in the Thames Valley, and extending inland almost to Morrinsville. The whole swamp comprised of an alluvial deposit in a state of ooze, which considerably hampered the construction of flood gates and stopbanks but the difficulty was eventually overcome. Up to 1920 some 37,451 acres valued at £229,800 were opened for selection and during that year 3155 acres valued at £54,400 were thrown open for the soldiers settlement.

The farms were from 70 to 150 acres and comprised of excellent land in fit state for immediate occupation. One point to be noted in connection with the land just opened was that it was on the seaward portion of the Hauraki Plains, and consequently derived a greater benefit from a drainage point of view by the rise and fall of tides. As the distance increases from the foreshore, so the difficulty of drainage increases, necessitating a comprehensive scheme of canals and drains to deal with water discharged from the watershed on to land. It was the draining of this area, outside the full influence of tides that has entailed so much preparatory work.

Transformation of Piako:

The cutting of these drains, determining the depths and levels at which they have to run, needed very careful consideration. Two important factors have had to be reckoned with; subsidation of the level of swamp as areas become dry, and the preservation of capillary attraction. The first important undertaking, (before a drain could be cut), was the removal of willows obstructing the Piako River currents, and clearing out snags and sunken logs. This was carried out from the mouth to the junction with the Waitoa. Several tongues of land, impeding the flow of the river were removed by dredges.

The Awaiti river was widened and deepened by the dredges for a considerable distance. The result of this work was that the rivers could receive and discharge flood waters, without adjoining lands being submerged. Lands which in previous floods would have been covered by flood waters to a depth of three feet are now unaffected by the rains and remain dry. The importance of these early operations demonstrated that nearly all of the 90,000 acres of swamp could eventually be made suitable for settlement.

The elimination of danger from abnormal tides was effected by the construction of a series of stop banks about four feet high along edges of the river and principal drains. Each drain and its outlet into the river, is fitted with a flood gate that closes automatically with the rising tide. Along the whole of the sea frontage extending for a distance of six miles, between the mouth of Piako and Waitakaruru rivers, a stop bank also four feet high was constructed. Thus by the combination of stopbanks, walls and flood gates, the tidal difficulty was largely overcome.

In case of any unforeseen contingency a most ingenious principle was followed to prevent serious or widespread inundation. Combination of stopbanks etc. were planned so that the whole swamp was sub-divided into a number of well defined areas each rendered independent and isolated from one another; which could be described as an island or water-tight compartment principle. In case of the bursting of a stopbank by the tide or river during an abnormal flood only a small area would be affected.

Following the completion of the initial drainage works there had been constructed 164 miles of drains and eight miles of stopbanks, together with 33 miles of roads. It was a difficult and momentous undertaking draining a large canal through the heart of a great swamp with all its attendant problems caused by a submerged forest in a country virtually unknown. The initial difficulties, however, are things of the past and the great water course now unfolds its silver length bearing seaward the swamp waters. Drainage operations have been so successful that use of the term "swamp" is no longer accurate. Much of that, is now plains well drained and fertile containing all the stored up and concentrated riches in the nitrates of the soil so long held in suspension. The land that awaited a farmer was full of potential qualities - as dairying country, much of it gives rich pasture in the province. Water there is in abundance and roads provide convenient arteries for the traffic and communications.

The Piako river was navigable right up to its junction with the Waitoa. Three miles from the mouth, the township of Pipiroa was laid out in a splendid situation. At the junction with the Awaiti stream, was the village and Maori settlement of Kerepehi with a store, Post Office, and telephone communication with Thames and the settlement of Waikaka.

Establishment of Flax-milling:

In 1904, Mr. Scotcher, together with 30 employees and machinery, moved to Waikaka.

The heavy machinery was brought over the swamp by means of block, tackle and jacks. A tramline was constructed and within three months the mill was processing the flax fibre. Two years later fires played havoc with the district. While fighting the fires, Mr. Scotcher and a party of his employees were surrounded with a ring of flame and had to take to drains, lying full length in water for several hours until the blaze passed over. By 1910, Waikaka was a busy settlement surrounded by magnificent flax country. Mr. Scotcher himself had over 400 acres in grass, 100 acres in turnips, 40 acres in oats, 200 acres under the plough and seven miles of fencing. Thus rapidly does the transformation of swamp to plain proceed, settlement spread, and enterprise and pluck manifest themselves.

The land was excellent but a pure domestic supply of water would have been a boon. An artesian bore was already in existence at Kerepehi which gave a full and regular flow. For some time the Department of Agriculture had had a large number of stock of approved breed running on the plains feeding entirely on native grass "Puroa", which grows to a height of three or four feet and makes excellent ensilage. The cattle thrive on it exceedingly. When the land was balloted for, the Department offered these cattle by public auction, to the incoming settlers, it being supposed that they would benefit from securing stock acclimatized to the district. A large part of the land offered was of exceptionally high quality, the entire absence of peat from many localities being a feature.

In 1910, a party of well known Auckland district farmers were conducted over practically the whole area of the swamp by Mr. J. B. Thompson district surveyor in charge of the drainage and survey works. They were impressed with the land, particularly the areas that were to be offered for settlement. The fruits of the Government enterprise were already within reach. Later the remaining 65,000 acres were pierced by the complex system of drains and waterways - the risks were many but the undertaking proved a success. The value of converting a huge sodden area like the Hauraki Plains into rich productive land lies not only in immediate return of wealth, but from national wealth created by settlement and industry. This project represented a courageous prolonged struggle with the elements. Nobody was more keen or enthusiastic than Mr. W. C. Kensington the Under-Secretary for Lands, at that time, and through the labours and creative thought of the Engineers, Messrs Breakell and Purchase, the capture of 90,000 acres of dry lands from river and sea-bed, passed into the history of New Zealand as one of its achievements in the cause of settlement progress.