FLOOD PROTECTION WORK FOR PALMERSTON NORTH

Manawatu Times, Volume LIV, Issue 6920, 28 May 1929, Page 9

FLOOD PROTECTION WORK FOR PALMERSTON NORTH

River Board Meets

The Palmerston North Kiver board at its monthly meeting yesterday decided on the. recommendation of its engineer, Mr. E. Fisher, to procure further plant at a ligure not exceeding £7OO to enable protection groynes to bo constructed at Hopcroft’s bond and maintenance work carried on simultaneously with the work being done above the Fitzroy bend.

Trustee A. J. Graham was in the chair. There were also present Trustees Yv\ L. Pitzherbert, Jcs. Batchelar, W. It. Hopcroft, W. Anderson, and J. Hodgens. An apology for absence was received from Trustee M. A. Eliott. The board decided to givo seven day’s notice of its intention to sue for all unpaid rates. Members expressed the opinion that the response by ratepayers to demands had been very poor. in introducing the engineer’s reports, Mr. Graham said that it was unfortunate that an “act of God’’ should make it appear that the work dono by the board had been futile. Such was not the case as 75 per cent, of the work done had stood the test of a severe flood and what damage had been suffered was more than compensated for by the losses the protective works had avoided.

Engineer’s report.

Mr. E. Fisher reported as follows: —

Flood results and effect on works: — Since your last meeting a flood of 14 feet above normal level was recorded on the 15th inst., this level being maintained for 24 hours, and following the flood of about the same level six months ago, caused a severe strain on the protection works generally, and particularly those recently constructed. In the circumstances I consider the works generally withstood a repetition of extraordinary flood pressure remarkably well. The original works at Mcßae's bend applied to provide immediate bank protection have been considerably damaged, but the new additional channel regulation w'orks havo appreciably saved the situation, in limiting the erosion and damage to the bank works to a minimum; otherwise the erosion would have very seriously developed. It is manifest that a complete system of channel regulation works is required to effectively control tho river in this bend, which is expedient for tnu purpose of providing and maintaining efficient and comprehensive protection of the town. I therefore confidently recommend the adoption of this course of action, and ask your authority to proceed with the construction of a sys- 1 tern of additional works necessary to effectively control tho river at this bend. Having not definitely decided on the extent of these works, I am at present unable to furnish an estimated cost of same.

Highly satisfactory results are evidenced at Fitzroy bend, where the complete diversion of the river has been effected, which makes it imperative that a sustained and determined effort be made to effectively control tho river at Mcßae’s bend. The success of these two works is identical and is intimately and essentially associated in the establishment and maintenance of permanent and comprehensive protection for the town.

Tho new works at Mr. Hoperoiu s sustained considerable damage and are now being reconstructed. Here extensive erosion of the river bed lias been developed, resulting in severe erosion of tlie bank, and a system of open regulating groynes is required to arrest this action, which I recommend be applied as soon as possible. Owing to the urgency of the extra works required here and elsewhere below this point, as well as at Mcßae's bend, and in order to timely cope with the extra work now involved, the board should provide another groyne constructional plant; viz., a punt, engine and winch monkey and other necessary gear, which I estimate would cost nc\v, about £foo. A secondhand punt may be procurable, in which case the cost would be less. This extra plant is required and should be provided.

Mcßae’s Bend No. 6 Groyne Extension: This extension is completed as planned, but I now consider it necessary to increase its height, and I recommend this be done, also to strengthen the original base portion of this groyne rendered weak by the flood. This -work is in hand.

No. 0 Diversion Groyne: Tho base portion of this groyne, being cable and willow work, was severed by the flood. I recommend that this breach be connected up to land with piles and booms and that two damaged groynes above this point be restored with heavy trees. I understand the settlers indirectly affected are prepared to sacrifice some of their tree shelter plantations for the purpose of properly restoring these groynes, and X suggest that in return the board provide the settlers with the cost of replanting their shelters. River Channel Improvement Below I'itzherbert Bridge: Tho day before the door a start wa s made and a number of logs were uplifted from the river channel, and this has had a good effect in the desired direction. This work I was resumed yesterday. When completed and conditions allow, the loghauling plant will be transferred to Fitzroy diversion channel. Flood Embankment at Foot of Rualnuc .Street: Matters in connection with ]an casement on the land required for this embankment arc in tho hands of your solicitor for preparation and excj cution. While I consider this work ! should not be deferred, in vicw r of the ! proposed financial commitments herebe- | fore mentioned, it will be necessary to I review your finances. My estimate of your financial position at the end of the year assuming that all the pmoposed

HEMES TO BE TAKEN TO MIKE TOP SAFE

works herein recommended arc agreed to, is that your revenue would bo exceeded by about £7OO. A margin of only two feet remained at the point of overflow with the last flood level; the matter should be seriously considered. The river at present is 2 feet 0 inches above normal. Special Report. In a special report to the chairman, the engineer, Mr. 11. Fisher, stated: “With reference to the river protection works at Mcßae's bend, respecting the destruction and damage of such works as a result of the recent high flood; and secondly, the relative importance and nccossity of these works to operate in conjunction with the works controlling the river at I’itzroy bend, constituting complete and efficient defence of the town. I estimate the loss in regard to works completely destroyed at £425, for damage to works (yet serviceable and capable of restoration) at £482, a total of £007; and for restoration of damaged works at £375. Notwithstanding the very considerable less and damage of works at Mcßae's bend as a result of the two high floods in quick succession, the fact remains that the works served well in preventing any material development of the erosion which factor I consider is commensurate with the loss and damage of works involved. It is obvious, with a full conception of the unrestricted development of the erosion as a result of the recent high floods that any effort made for the retention of the defence works at Fitzroy bend would be futile, It is my well considered opinion that the eminently sound defence now completely established at Fitzroy bend hai removed a very real menace to the town and that fixed and united determination to conserve intact these defensive works should prevail regardless of cost. Therefore I am confident that fixity of purpose is essential and should guide the board in determining their future policy. While I fully appreciate the magnitude of the problem presented at Mcßae's bend I am confident that with the application of the additional wmrks as recommended in my report before you that it can bo definitely and successfully solved. Question Discussed.

Trustee Batchelar said that he had visited Mcßae’s bend and that ho saw the damage that had been done. The speaker recalled that some months back when the engineer recommended two cuts he supported him. If the t/'o cuts had been put in the damage caused would havo been lessened. Mr. Fisher stated that his opinion was that the second cut would not have prevented much damage. Tho troubio was caused through the lodgment of shingle. The only way was to accelerate the flow of the river and so naturally dispose of tho shinglo banks which were the cause of tho trouble.

Tn reply to the chairman, Mr. Fisher said that it would cost £375 to repair the damage done by the last flood. Trustee Hodgens was of tho opinion that the work should bo proceeded with. The board should provide the engineer with the extra gear necessary for protection work at Hopcroft’s bend. Mr. Fisher explained the urgency of the work required at the old racecourse where the borough septic tanks were endangered. There would be no further increase in staff required. The work could be done within the present revenue.

In reply to Trustee I'ltzneruuri, the engineer stated that the only way to control the river was by groynes. If it had not been for the groynes the cut at- Fitzroy bend would not have formed. The present type of groyne would withstand a flood.

The engineer questioned as to the advisability of permitting shingle to be removed from the river replied that the removal was entirely in the board's interest as it caused the flow to remain in the centre of the stream and so relieved tho pressure on both banks. Both reports were adopted, the board deciding to authorise the purhase of further plant and also that the engineer bo permitted to proceed with a flood protection embankment at the foot of Ruahine street not to cost more than £IOO.