FLOOD ISSUES DOMINANT IN BOARD’S PROGRAMME; SHINGLE DRIFT MENACE

Gisborne Herald, Volume LXXV, Issue 22665, 16 June 1948, Page 6

FLOOD ISSUES DOMINANT IN BOARD’S PROGRAMME; SHINGLE DRIFT MENACE

In submitting a comprehensive report upon the activities of the P.B. Catchment Board at yesterday’s meeting of the hoard, the chairman, Mr. J. R. Hair, pointed out that the recent flood disaster was not covered in detail, as it did not fall within the period to which the record referred.

“In discussing future activities of the board, however, it would be unrealistic to ignore the fact that since the end of the period under review the Gisborne district has experienced the worst flood in its recorded history, and that this fact will dominate the board’s activities for some time,” continued Mr Hair.

viously under grass and subject to silting only, and the riverbed appears to have risen in this vicinity. Shingle also has been deposited on a moderately high terrace as far downstream as Mr. CraiH's property, Waipaoa, some 25 acres being covered to depths of from 6in. to 18in. Cross Sections Under Check

“The most pressing task is of course the completion of proposals for flood control, engineering surveys for which had fortunately been completed before the flood occurred, and also the active prosecution of the flood damage repair work now in progress.

“In view of these disturbing facts, two survey parties are now at work checking a proportion of the crosssections already established for this purpose so that precise information can be obtained. At the same time flood levels will be taken at regular intervals to obtain the flood gradient over the full length of the river. “Waipaoa River Control Scheme. — Plotting of the river survey is well forward. By next week sufficient data will be assembled to enable a start to be made on the design of alternative schemes which it is expected will take about six months to complete. “Work in Waipaoa Upper Reaches.”— The grant already applied for will serve to carry out the experimental work, nursery planting and opossum control in Te Weraroa area. “It is important however, to explore the possibility of doing preliminary planting work of a similar nature in other parts of the Mangatu and Waipaoa upper reaches this planting season. A report on this matter will be submitted as soon as the area can be examined in detail.” The encroachment of shingle accretions on areas previously free from this menace was regarded with especial concern by Mr. G. Newman, who pointed out that this menace was getting nearer to the point where it would threaten the existence of the whole of the Gisborne flatsHe had discussed the possibility of dredging to control movements of shingle, but he had been informed that the board could dredge for a thousand years and still do no good. The problem was one of control in the headwaters to prevent the fast run off which carried shingle down the river, said Mr. Newman, and this was undoubtedly the most urgent matter facing the board.

“At the same time it will be absolutely essential to continue with soil conservation activities, particularly those of an experimental nature, as early results in this direction will enable preparation of detailed proposals for headwaters control in the Waipaoa River which must form part of the flood-control scheme.

Works Receive Big Impetus

“Having now assumed control of all watercourses in its district, the board during the current year will be increasingly preoccupied with drainage problems, the flood having already given drainage works a considerable impetus. Many urgent matters therefore claim attention, and the coming year will be a full one for the hoard and its staff.” The chairman thanked the executive officers and start for loyal and unstinted service throughout the year. Discussing leading flood aspects the board’s engineer, Mr. A. D. Todd, referred to the increasing hazard of shingle deposits in the Waipaoa River Valley. “Inspections of the upper reaches of the river reveal an extraordinary increase in activity of all the existing gullies in the Tarndale area, and the appearance of a number of large new slips which will rapidly develop into gullies,” he declared. “The effect on the Mangatu River and Te Weraroa Stream has been to raise river flat levels still further. Shingle has been dropped on several flats near Whatatutu which were pre-