RIVERS COMMISSION.

Hauraki Plains Gazette, Volume XXXII, Issue 4318, 16 September 1921, Page 2

RIVERS COMMISSION.

THE FINAL EVIDENCE.

The following is a continuation of the evidence given before the Waihou and Ohinemuri Rivers Commision.

THEORETICAL KNOWLEDGE.

Continuing, Mr Baker said his statement was based on his 'theoretical knowledge and his own observations, but the latter was not spread over a lengthy period. He had not examined the bottom of the river, and knew his evidence was sound. He certainly thought his evidence was as good as that of any experts who had observed conditions for many years. He thought the statement that 75 per cent, of the sands, etc., flowed right out to sea was improbable. The deposits now on the bed of> the Ohinemuri are capable of withstanding flood action, as they are sufficien'tly tightly packed. The lower Ohinemuri is largely engorged wi.th mining sands. The Ngararahi cut was necessary as a part of the Public Works improvement scheme, considering the condition bf the lower Ohinemuri. The cut would improve that portion of the river as a .waterway. The land drainage scheme would have been eventually necessary, irrespective of any damage that may have been_caused by the mining industry. In the past ten years his Department had cleared willows from the Ohinemuri, erected a stop-bank, anl made concrete flood outlets. On the. Waihou bank near Mangaiti land now cultivated would not be likely to flood. He did not agree with Mr H. R. Young’s figures as to the amount of water that flowed over the banks of the Waihou in flood time. His Department has taken no steps so far to recover the cost of works improving the Rotokohu district. Had the Ngahina bridge, when built several years ago, been erected to cover the whole of the waters coming down even in -flood time, the bridge would have had to extend right across to .the Awaiti.. The recent extension, at a cost of £9600, would cover the whole of the waters which were confined to one definite course. He would not say that his Department had a reasonable expectation of completing the whole of the work in the next five years., Under ordinary circumstances the work should be completed within that time. The work now is largely for land protection. The efficiency of the Department’s work had been somewhat affected by the clamour of farmers and local bodies within .the area. He had in preparation a proposed basis of contributions. Matamata County would be a contributing district owing to it receiving an improved waterway and improved drainage, and the fact that more water coming down from that area necessitated higher stopbanks lower downstream. Piako County was similarly situated, but .o a greater degree. Te Aroha and Paerpa boroughs should also contribute. Ohinemuri County lands and the Hikutaia Riding of Thames County should also contribute. Thp miping industry should bear a lesser proportion of the necessary contribution than in the past. Waihi should also contribute, but it should be given some quota of gold revenue to permit it to carry on its municipal duties as .the borough was unable to rate mining companies within its limits. ASSURED FINANCE.

Mr Johnstone here advocated giving Waihi an assured minimum revenue of £5OOO per annum, with a sliding scale providing for one-fifth of the total gold revenue. It gold revenue fell below £5OO, then Waihi should receive the lot, and should be required to make up frpm rates or other sources any additional revenue for the conduct of its municipal affairs.. He was glad to see that Mr Baker proposed, even at this late, date, to “rope in’ Matamata.

This statement the chairman welcomed as an important one. It re.scmbled gold in a lot of mullock. Mr Baker added that only that portion of Matamata County in the Waihou basin should contribute. Piako County likewise, but including a portion of it that received improved river communication. Speaking generally, all lands, either freehold or Crown, which receive benefits, should contribute. One object of .the Ngararahi cut was to reduce the cost of stopbanking on both sides of the old Waihou and Koutu meanders, and another was to improve the flow of water. There was no need to put a long bridge at Ngahina at the time. Data was not complete at that time. Had the 1910 Commission been investigating to-day its findings would almost certainly have been very different/in the light of fuller data. To Mr Clendon, witness said he favoured the Department removing shoals at Mangaiti. This would not be costly, and would materially benefit Te Aroha and Piako’s river navigability. So far requirements in the upper Waihpu have been subordinated to the needs in the lower reaches. The 1910 Commission recommended stop-banking right up to T.e Aroha where required. He did not favour stop-banking the right bank to protect Mace’s and Fitzgerald’s lands. The work in the whole .area is being done as cheaply as possible.. He would not favour purchasing new machinery until the financial position /is determined. Indications are that there will be a slight fall in the cost of material, but not of labour for some years yet. Hence his estimate of £625,000 to complete the whole work. The mines should contribute about £97,000 towards the whole cost of the scheme. The Rotokohu work was partly necessary owing to the flooding of the Ohinemuri.and was essential to the stop-banking scheme. He thought the mining interests and Waihi, who were seeking exemption, should put forward a suggested readjustment of the costs over other contributors.

Mr Johnstone, at this stage, said •the mining interests and Waihi claimed that the scope of the Commission was confined to an allocation of the cost up to £150,000 for the whole work. Waihi Borough required a minimum of £5OOO per annum from the gold revenue to enable it to maintain the ordinary municipal services.

Cro.wn lands and freehold lands benefited should be loaded, and the Consolidated Fund should contribute the balance. Mr Clendpn: What about the mining interests ? Mr Johnstone: The mining interests should contribute from gold revenue on a sliding basis. • He felt sure it would be generally admitted that the allocation of 1910 w,as unfair. The mining interests had , had no say in the expenditure of the money. Ifjthe farmers contested the right of the Government to benefit their lands the Government should test their bona fides by at once ceasing all further work.

Mr Richmond pointed out that the first money was borrowed at 4 per cent. Other money will cost at Ipast 6 per cent. Mr Johnst.one said the question of ability to pay must be considered. It was impossible for the mining companies to pay £97,000 or, one-sixth of the estimated total cost, whatever that may eventually be. Witness, continuing, said the floodwater fall in Pereneki’s cut would be 12 fee.t per mile. Mr Young’s figures in this respect were based on nprmal flow. PAEROA AND NAVIGATION. To Commissioner Buchanan: To/ prevent the silting up of the Ohine- . muri River, as recommended by the 1910 Commission, no steps had so far . be.en taken, except the minor improvement caused by the removal of willows. He believed it was intended to restore .the river’s navigability. He did npt .consider such restoration economically practicable. If Paeroa was to be compensated for the loss occasioned by the unnavigability of the river the parties responsible for this loss should bear the burden. The stop-banking of the left bank of the Waihou near Wiggins’ would not oe permitted tp menace the lands on the left bank. If no stop-banking were done the railway line and portion of Rotokohu would be liable to damage. His estimate was based on the condition of the river at' the present time. A considerable area of land had been made immune from moderate floods * much other land was partially prptected. There ,was a danger of a higa flood crossing near Wiggins’ end and damaging .a large area behind the stop-banks. That area should be rated, even though pnly partial protection was at present afforded. By the time a rate could be collected the improvement works above Tirqhia would ; r should be practically completed. When ■the improvement works .are competed the land in the Rotokohu area wouldbe protected, except against exceptional floods. About 30 chains , above the junction a floodgate would oe made on the bank of the Qhinemuri to deal with excess water coming down from the small watersheds behind Rotokohu. On the upper Waihou, above Mill Road, borrow pits will probably be cut above ordinary water level in connexion with the stop-hanking ”.p. towards Mangaiti. Damage caused to Paeroa 'through loss of river communication should not be balanced against benefits derivable through land improvement and protection against flood damage. He suggested that when the improvement works are completed maintenance would absorb about £9OOO or This would include working expenses of a dredge that would be retained on the river for casual remedial works. To work the dredge regularly would absorb about £4OO per month. He hoped dredging would only be required for two or three months per annum. Floods in the Waihou are about one moderate-sized flood per year, and one that was of sufficient volume to move sand deposits should occur every second or third year.

' To the chairman; witness detailed several matters in connexion with dredging that would be administered by a river hoard. If the improvement work is to be completed in a reasonable time h,e considered a river board should be set up so .as to be in full working order just prior to the completion of the works. The Consolidated Fund should not be expected to contribute more than one-sixth of the cost of improvement works. He could not express an opinion as to who should bear the cost if the mines ceased work. The Thames Borough endowment lands, between Tirohia and Mangaiti, would be considerably benefited. On the basis of expenditure, about one-third of the improvement works had been done. The Mangaiti bridge should be lengthened to avoid backing up the river waters. This would not affect navigation. The approaches restricted the flow of water at flood time. Lengthening would cost about £6OOO. When the improvement works are completed there will be • a sft channel at low water up as far as the Ngahina wharf. Occasional dredging may be necessary to maintain that depth. THE NGAHINA WHARF.

Continuing, witness said the Northern Co. and the Department were not in agreement on the matter of boats using the Ngahina wharf. The whole cost of the Ngahina wharf approaches was £4600. The Paeroa-Pokeno railway had been trial-surveyed, but the point of. crossing the Waihou had been definitely fixed. From Paeroa. north of the station yard, the line would run straight across, practically parallel with the Puke j.Road. All plant at present used on the improvement works had been debited against the works. It was worth about £40,000. He was sure that indemnities offered by Hikutaia farmers against flood damage, as made to the former Commission, had been accepted. Some additional plant was needed, but before this could be landed on the job the need for it would be lessened by the present methods adopted. The estimated cost of Pereneki’s cut and other works collateral was over £21,000. It will be necessary to raise the railway bridge at Paeroa. This would cost about £2500. The stop-bank would be raised simultaneously to prevent flood water coming over ■the town. The Criterion bridge shpuld also be raised about 3ft, but this work would not be undertaken for some time. All stop-banks were calculated to provide a 2ft “freeboard.”'

OHINEMURI NAVIGATION.

Re-examined, Mi: Baker said no works were contemplated to provide navigation on the Ohinemuri, as construction and maintenance would both be costly, in view of the mining debris constantly coining down. His estimates of lands to bear the costs were only approximate. PAEROA HARBOURMASTER. Robert Thorp, harbourmaster for the Paeroa district, and a qaulified master mariner, said he had a knowledge of the river since 1908. The lower portion of the Waihou was gradually becoming worse tor navigation, .the river’ was shoaling up, the bed was hardening from Cryor’s Landing to Ngahina, except for an area near Hikutaia. In the navigable channel there was more loose shifting material, but nearer the sides the material was more dense. He was on the “Waimarie,” going downstream, during the 1920 flood. This was the first time he had noticed water running inland near Nethertpn. The' Turua middle hank was encroaching on the channel, the Matatoki spit was extending; there was also an encroachment at Elliott’s wharf, Wharepoa. He had a passing knowledge of the Wainou River up to Te Aroha. There were several shoals downstream from Mangaiti, and two or three .above that place. River traffic •to Te Aroha since the Ngararahi cut was made was dependent upon the tides. From Puke to the dredge near Tirohia there was no appreciable improvement to navigation, but the .cut would be beneficial later on. For the past ten years the lower Waihou has been becoming gradually worse for navigation. v To Mr Hanna: Boats almost al* ways drag, on the bottom practically all the way between Nethertom and Paeroa. If Pereneki’s cut were put in steamers could come from the Ngahina wharf to the old railway wharf in about half-an-hour, but on arrival they could not turn round. The Waimarie was 120 ft long. A turning basin might be made. To Mr Gilchrist: The difficulty in navigating up to Thorp’s was due mining tailings. He had not taken a boat up to Te Aroha for six years, but had gone up as a passenger recently. At some of the shoals they had difficulty in getting up, and had to put a line ashore. The boats drew 42in and 51in, Inhere dredging had been done the- banks were gradually slipping in The sands would work downstream. To Mr Richmond : He had taken a quantity of mining silt out of the Waihou at Cryor’s Landing, and had been up to his armpits in it for an hour at a time. It was virtually a quicksand at certain times. The Ngararahi cut caused an enormous amount of sand to travel downstream. To Mr Johnstone: In the lower W.aihou, there was shifting sand in the “gutter,” used by boats. Up to the present the river improvement works had not benefited navigation up to Te Aroha, but he expected some improve/nent later on. The soft mud bn the sides of the lower Waihou was much less than. formerly. The fall-ing-off in cargo to Auckland was mainly accounted for by the fact that bu,tter was being made now instead of cheese, thus reducing the bulk to be transported. Jie could not recollect two successive seasons as dry as the two just past.

To Mr Clendon : More pumice sand was coming down since the Ngararahi cut was made, owing ’to there being more scour. LEVELS IN AWAITI. Wm„ Barclay, civil engineer, said he had been in Paeroa for 18 months. He had done most of the levelling in the Awaiti, and described on a plan the amount of levelling done by him. A portion of the country was soft peat and waterlogged. The land in most places was not firm enough to stand upon. Poles were used for level-tak-ing. The peat was quite 12 feet to 15 feet deep, probably more. There was some running water in that area. He did not recollect any evidence of floods there, and in his opinion flood waters would not reach that portion of the Awaiti where he had been taking levels. THE PIAKO SIDE. A. H. Grant, engineers’ assistant, Public Works Department, Paeroa said he had been in the employ of the Department for over eight months. He had taken levels on the Piako side of the Awaiti. Half a mile in from the Waitoa the country was flax swamp and then soft, peaty country. He had connected up with ■the former, witness’ work. He had seen no indications of that portion flooding. There was a peaty ridge close to the Piako River. Samples of silt had been taken from the river at selected points about a mile apart.

L. E. Shaw, a chainman, had been in the employ of ’the Public Works Department, Paeroa, for five years, and had assisted Mr Barclay in his levelling in .the Awaiti. He confirmed the former witness’ evidence that the land ,was composed of deep peat, and had found considerable difficulty in walking. No evidence of floods had been seen. He had seen a small flow of water. CHIEF DRAINAGE ENGINEER. j> B. Thompson, Chief Drainage Engineer foi- the. Lands Department, had been connected with the Department since 1908, said that the Hauraki drainage was under his supervision from the'water to this side of Morrinsbille. The Crown owned 27,000 acres between the Wai to,a and the Piako, and the Awaiti. The better portion of the .. country was nearer Kerepeehi, south of which there were 2000 acres of good land, 1700 being rich alluvial land. The valuation of the 2000 acres was £l6OO and when drained it would be worth £3O per acre. His Department did ' not seek ■to make a profit, but asked a fair value. LOADING THE LAND. It would cost about £lO per acre to drain that land. The Department was dredging a canal up the Awaiti. .That land should be loaded with about £3 per acre to help to pay for the river protective works on the 2000 acres block.- About 634 M). acres immediately south was peaty but resting on rich alluvial. This would derive benefits from the river works, and about £3 per acre would be a failtax. About 13,800 acres of the 27,000 acres would be. directly benefited, and about 6000 acres could bear £3, and 7800 acres £l, and 9500 indirectly benefited could bear as follows: — 1500 acres at £l, the remainder at 10/-. Another 80Q0 .acres was poor low-lying flat, peaty country, and in his opinion would not be worth much and would sink about 60 per cent, when drained. This was the most difficult country his department had. A lot of the country would have to be pumped if it was to be utilised, and the development of 'this area had been left olane on account’ of other areas, which were more easily accessible. It would be a costly matter to road this land. There was no land across the Piako which would gain benefits from the river works. The tide influence extended as far; as Tahuna, 28 miles up the Waihou.. LAND SALES AND VALUES.

To Mr Porritt witness said that no effective benefits could be received between Kerepeehi and Wharepoa. Questioned by Mr Hanna witness said he had heard of more than one occasion on which flood wafer had overflowed near Netherton. The Department considered it a moral obligation to protect the tenants of land.. He could not‘say how the 9000 acre block of land was acquired, but thought that it was purchased from the- natives. The whole general fall of the Hauraki Plains from .the Thames Borough Endowment, was north west. - The fall of the Piako River between Tahuna and Kerepeehi was about 40 feet. His Department had not taken any levels south of Kerepeehi as they had no work to do there. The fall of Te Awaiti Stream averaged about 6 inches per mile. Some of the Crown land cost about £lO per acre. Improvements by the Department cost about £3 per acre. Land was sometimes sold at £3O per acre. On the other hand they had bought at £l5 per acre.. They did not expect to get any price in advance of £l5 per acre. In drainage works the Department’s first object w.as to find out the outside cost before commencing the works.

TREMENDOUS APPRECIATION. To Mr Richmond: About 42,000 acres of Crown land had-been disposed of at £310,000, but was worth about £1,500,000. The Piako River could no-t carry its flood waters without stopbanking and that was practically true of all rivers here. The Piako River would carry 12,000 cubic feet, per second at its highest. To Mr Johnstone: The Department’s work, in his opinion, had been a complete success. During witness’ visit to America he had found that that country was ahead of this in drainage matters. The Department had experienced great difficulty in obtaining suitable drainage machinery. The dredging expenses here were not abnormal. Suction dredging in America cost as much as drag-line and dipper' dredging. Huge sums of money had been made by farmers on the plains. Had the Department known, it could have held on to the lands, and more 'than paid for the drainage works. From 1910 on, large profits had been made by some people, and since 1911 the Department had disposed of lands at better prices. The Piako River was not a silt or sand-bearing river. There was only blue mud in the Piako, There was

sand in the Waitoa. The Department once spent a good deal of money snagging the Waitoa. The Department had consolidated local bodies money contributed for snagging high up ’the river. THE PLAINS PEAT LANDS.

Re-examined by Mr CLendon witness said the property on the plains had received a set-back recently. The flood water from the Waihou would flow about half a mile west pf the Awaiti stream.

HIGHEST VALUED LAND. Replying to Commissioner Shortt witness said that the Hauraki Plains land was 'the highest valued land the Department had sold. He had no control over the River Boards on the Hauraki Plains. The Internal Affairs Department controlled .the Drainage Boards. To Commissioner Buchanan: The lands lying to the east of the Awaiti drained into the Awaiti. It took a week to get a flood down in the Piako. He had no data showing the capacity of the Awaiti basin. The Department had had temporary grazing over a portion of the country. It would be impossible to settle the 2009 acres unless a stopbank were erected on the Waihou but pumping might have to be done. A section of the Piako River would be improved below,. Whether the settlers in the Piako County should pay for drainage benefits he was not prepared to say. PLAINS LIGHTLY RATED. In reply to the chairman, witness s.aid the Hauraki Plains people were paying a maintenance rate of 2d, 1 7-50 d, and 7-25 d in the £. The lairds bought from the Crown were immune from the County rates for four years. The Hauraki Plains was a lightlyrated district. This area would bear further rating, and w.as a highly prosperous district. MR McMORRIN’S OPINIONS. Mr R. G. McMorrin, Government Land Drainage Engineer, and once a resident engineer on the Hauraki Plains, of which he was familiar, said Thames had been his headquarters. He agreed with the former witness’ views of the land in the Awaiti district. He was doubtful if draining by gravitation would be successful. An area of 17,000 acres would probably require pumping.

To Mr Richmond : His work wks oh the western side of the Piakp, above' Kerepeehi. To Mr Johnstone, witness said he. had only been in this district twice during the past ,five years. Department got from £4 to £l5 for the Patetonga land .after it was drained. His business was to sell the land at the smallest possible profit. Re-examined by Mr Clendon, witness said he had tested the depth of peat, which was very deep in the upper portion of the Awaiti. The distance from Patetonga to the hills was about 3% miles and the deepest portion of peat was nearer the river. Near the hills the depth of peat varied. A high price had been obtained on certain peat lands. • Answering questions by Commissioner Buchanan, witness said he knew of launches going up the Awaiti basin without following the course of the river about Kerepeehi. He did not know of floods coming over from the Waihpu into this basin. The flood water would rise about sft above the high-water, level. The sections recently opened on the Patetonga tramway had been let to returned soldiers. There was very little freeboard up there when the river was at its normal level ; the lands were liable to flooding. An overflow from Awaiti and Ne.therton had been, known.

THE RESIDENT ENG [NEER. Mr L. May, assistant engineer, public Works, Paeroa, and civil engineer, said he had been in charge of the Public-Works at Paeroa for the p.ast 10 months. He had heard the evidence of the district engineer, and agreed with his opinions. His Department had taken a series of cross-sec-tions on the Ohinemuri and Waihpu rivers from 1915 to date.. He produced .a plan of the portions where the cross-sections were taken and a graph showing the comparative depth of the waterways. The .waterway in the first section had increased in area 350 square feet from 1917 to date; the section had changed a little, shoaling up a 'little. In other sections the areas had shown increases and .decreases. The Department had done a certain amount of dredging. There were also sieveral parts of the lower Ohinemuri which had been under observation. At only one of these plac-' es had a cross-section been taken,

and showed a decrease in the waterway. As far as could be ascertained from panning the samples taken from the bed .at this point .appeared to consist of mining tailings. The river-mt this spot showed a tendency to shoal, just above the Koutu cut the area

had lessened 460 feet. Some of the samples taken near the Koutu cut had been sent to the School of Mines for a report. One had showed 6 pennyweights of silver and 10 grams of gold per ton. Samples taken by .Grant w.ere taken under witness’ instructions. The Department had not been hostile to the Northern Steamship Co. A series of sounding had been taken in the upper Wailiou from the top end of Koutu cut to Te Aroha wharf.. He got a depth a.t every half chain all the way up last January. Soundings had previously been taken by his Department on this part of the river. He produced a plan showing the relative depths of water between Tirohia and Te Aroha. There had been an average of 9in in the Ngararahi cut. Other places there were increases of Jin, 2ft lin, Ift 2 in, Ilin, and 7in, ,and decreases of 9in in two places, and 3in in three other places. minimum depth, as far ,as he could remember, was about 3ft 3in. His soundings had been taken in a very dry month. The Public ■ Works operations had extended as far ( as just below Tirohia bridge. The ' operations had tended an increase in ' depth. There was a fair fall in the . upper sections of the river, but compared with the Ohinemuri it was comparatively small. The river required deepening another foot in places. , This would be no difficulty. A Cle- , trac tractor had demonstrated the re- ; moval of earth at a cost of 4s per , cubic yard. I Mr Johnstone : On the strength of ; the demonstration they bought three.. Witness : That is not correct. | To the chairman, witness said the town of Paeroa was fairly efficiently , protected from floods. A wharf would cost about £6OOO and upswinging basin 1 £lOOO if navigation were-brought up j to Paeroa again. To bring up the . Waimarie and the Taniwha i,t would ! save about £560. In his opinion it would be inadvisable to put in the ; Pereneki’s cut.