OF THE SEA.

Taranaki Daily News, 9 August 1921, Page 5

OF THE SEA.

EROSION OF FORESHORE. BIG PROBLEM INVOLVED. LOSS AT EAST END RESERVE. DANGER TO WOOLCOMBE TERRACE. “It is a tremendous problem for New Plymouth, because last week showed that the whole front of this town is threatened,” said the Mayor (Mr. F. E. Wilson) at last night’s meeting of the Borough Council in discussing the question of erosion along the foreshore. The damage done by last week’s storm was the subject of reports from the council’s officers, and after discussion it was decided that the council make an inspection of the foreshore next week.

Referring to this subject in his monthly report, the general manager (Mr. F. T. Bellringer) stated: The question of sea erosion has been before each succeeding council for many years past, but the erosion is becoming so extensive that some comprehensive scheme to cheek it will soon have to be evolved. This will entail’an enormous expenditure, at a time when the council is not in the best of positions to meet it.

For the information of the council Mr. Bellringer quoted a report from Messrs. Blair Mason and Lee, presented in November, 1919. Their report mentioned, inter alia: There is a strong presumption that the ra'■ ■ f encroachment has been acceleratet’ late years through interference with ihe natural condition of the shore, between high and low water, by the removal of stone and boulders. These latter formed a natural barrier against the seas, which thereby lost much of their power to un. dermine and damage the cliffy shore. What may be viewed, however, as the more serious result of the removal of boulders, is the scouring away of the easily eroded shore between high and low water marks, and the consequent lowering of the beach. This action allows the waves to break with ever increasing force againist the cliff face. If not stopped it is inevitable that Woolcombe Terrace and the Plantation Reserve will more or less rapidly melt away and disappear. REMEDIAL .PROPOSALS.

The diagnosis of the cause suggests the means necessary to slow down or stop the injurious effects described, and now taking place. These are confined to: (a) Placing heavy rock one boulders along the shore, upon which the seas can expand their energy, and protect the cliff and shore from wave action; (b) facing the cliff and shore with a solid concrete wall high enough to be above the wash of heavy seas, and so entirely protect the soft and easily eroded cliff material.

Referring to remedy (a), it becomes a question of an adequate supply of suitable stone from a sohree, other than the beach itself. . The stone of the seaward part of any protecting wall would require to be in not less than five ton masses to prevent, their displacement by breaking seas. As there is no easily available and cheap source of atone, consideration is advised to be given to remedy (b). This proposal ■ consists in extending a concrete sea ■ wall along the base of the cliff from the end of the stone protection wall of the Railway Department, to a suitable point south of the pavilion near the Henui River. To prevent undue drift of sand and shingle along the base of the wall, short buttresses or groynes can be placed at intervals. A talus of stone may be found necessary to prevent any cutting out of the wall footing. Referring to this report, the general manager stated: I do not altogether agree with the suggestion that the rate of encroachment has been accelerated of late years by the removal of stone and boulders. With the exception of a. few boulders moved inshore for the protection of the East End Reserve In 1905. it must, I should imagine, be 25 to 30 years, if not more, since stone was removed from the beach between the TTuatoki and Henui streams. Even then the materials removed were largely small, loose boulders for breaking into road metal, and the quantity was comparatively small. EFFECT OF BREAKWATER. . It is only of late years that the erosion has become serious, and this must, I think, be due. in some way to the lengthening of the breakwater deflecting the deposit of sand further eastwards, and so allowing the beach to become lowered. It is a question whether the Harbor Board, in cutting off the supply of sand to the beach, has not become liable for some part of the damage now being done. Although this liability may appear to be very remote, still I think it is a phase of the question which should be investigated. With regard to the damage at the East End Reserve, I endeavored unsuccessfully last year to persuade the district railways engineer to recommend his department to contribute a proportion of the cost of the permanent protection works west of the Henui stream. There is no doubt that any protective works effected here would be of great value in protecting the railway embankment. He, however, could not see his way to do anything in the matter, although I even went so far as to say that I would recommend the council to remove the East End pavilion and abandon the reserve to the sea, pointing out that if this were done the whole of the expense of protective works would fall upon .the Railway Department. REMOVING EAST END PAVILION. I think now that the time has arrived for the removal of the pavilion to a safer position inside the railway embankment, and I would recommend that this be done. It will be some considerable time before money can be raised for permanent protective works, and it is unsatisfactory to expend £6OO to £7OO on temporary work every year to be washed away by the next severe storm. So long as the building remains in its present position, and until the problem of checking the erosion has 1 been solved, there is no option but to keep on replacing the temporary protection work, and it would ease matters considerably for the council if the building were removed. It might also have the effect of inducing the Railway Department to contribute towards the cost of some more permanent work. After reporting on the measures taken in connection with last • week’s storm, the borough engineer l

(Mr. W. H. Cook) stated: The work done is extremely temporary, and will not withstand heavy pounding seaa. Any permanent works will bo costly. The frontage can be protected either by (a) a concrete sea wall; (b) heavy cribs filled with stone and groynes; (c) renewing the breastwork with more substantial timbers and railway irons, with groynes. In any of the schemes adopted the work will require to be brought up higher than the previous work and backed by strong coping. Tn the meantime the work of strengthening is in hand, as similar storms may again be experienced during the next tjvo months. In dealing with the question of the ?ost of permanent work, it will be a matter for the council to consider whether the small amount of land between the railway and the sea will war rant such. If it be decided to erect substantial works, then the question

arises how far from the shore line such should be placed, or, in other words, how much land can be reclaimed, and its worth to the town when completed. OPINIONS OF COUNCIL. Discussing these reports, the Mayor said his opinion was that the pavilion at East End should be shifted back to where the swings were now situated; this represented a distance of about 100 feet. He did not know how the council were going to protect the foreshore. In suggesting the removal of the pavilion he pointed out that he was not in favor of placing it beyond the railway embankment, as its primary purpose was for use as a bathing shed. The building, however, ought to be placed on another site at once.

Cr. R. L. Parkin said that in the past few years the erosion which had taken place at East End represented some acres. He did not think it advisable to put the pavilion on the sea side of the railway line. The Mayor pointed out that there was a far more important part also awaiting attention; this was Woolcombe Terrace, where the cliffs were being rapidly undermined. If the damage went much further this vicinity would rapidly depreciate in value. He agreed with the view that the harbor worki were mainly responsible for the erosion. Cr. J. Brown also urged the necessity for prompt action, and he also mentioned the beach near Kawaroa, and the baths, as parts needing protection. In regard to East End. he favored shifting the pavilion beyond the railway; they had lost practically the whole of the reserve, and he believed it was foolishness to try and protect the building as it stood at present. If the council did not shift it they should sell it for removal, for it would be washed out to sea very soon if left on the present site. The council then resolved to make an inspection of the whole foreshore next week on a date to be arranged.