SELWYN RIVER DRAINAGE

Press, Volume LXXXIII, Issue 25207, 11 June 1947, Page 4

SELWYN RIVER DRAINAGE

LANDOWNERS GIVE APPROVAL

RATING TO BE SPREAD OVER EIGHT YEARS Approval of the drainage scheme proposed by the North Canterbury Catchment Board for the Selwyn river area was given unanimously, at a meeting of residents at the Irwell School last evening. On the motion of Mr P. V. Bailey, chairman of the Springs County Council, seconded by Mr W. O. Rennie, the meeting decided to request the four county councils concerned to collect rating on the scheme for the Catchment Board, and to authorise the striking of rates on’ an eight-year basis. About 70 residents of the Ellesmere. Springs. Malvern and Selwyn counties attended the meeting. The chairman of the Ellesmere County Council (Mr A. Anderson), who is a member of the Catchment Board, presided. Mr W. Machin, chairman of the Catchment Board; Messrs Hugh Anderson and M. Spencer Bower and Dr. G. Jobberns, members of the board; Messrs W. W. Brough (secretary of the board). H. W. Harris (engineer), E'. B. Dalmer (assistant engineer) and R. D. Dick (soil conservation officer) were present. Technical Aspects Explaining technical aspects of the drainage scheme, Mr Harris said that the heaviest ram in the Selwyn watershed of 256 square miles fell at Homebush, where a maximum yearly fall of 58 inches had been recorded. The average rainfall over the watershed was about UJ inches a year. Records showed that floods were experienced in seven different months of the year, but February was about the worst month. Since 1923, there had been 17 big floods*, and it was reasonable to expect an average of one big flood in the river each year. A major cause of trouble ih the river course was the growth of willows in the lower portion, where the. course was now practically choked. The drainage scheme envisaged the opening up of the course, which would be cleared in the lower reaches to a width of about 300 feet. Stopbanking would be put in over a length of 19 miles to prevent overflows. The amount of lateral erosion was found to-be much less than had been thought, continued Mr Harris. However, the erosion was bad. It was not proposed to put in groyne work; where lateral protection was needed, it would be put in parallel with the banks of the river. The drainage scheme aimed to delay the movement of shingle as much as possible. The idea was to trap it in the bends of the river and so give added protection against lateral erosion. At the Ellesmere bridge, it was proposed to raise the level of the small 30-foot span and its approaches so that rises in the river would cause no interruption to traffic on the-highway. Replying to questions, Mr Harris said that if the scheme was approved, there would be 90 per cent, relief to drainage problems within two years. Adequate machinery was available to keep down the level of Lake Ellesmere, and every effort would be made to keep it down. It was likely that under the new system of rating, the lake could be released more frequently than in the past at a greatly reduced cost. Government Subsidy Mr Machin said that the scheme could not be possible without the cooperation of the four counties concerned, the North Canterbury Catchment Board and the Soil Conservation and Rivers Control Council. He had reason to believe that a Government subsidy of £3 for every £ raised in the counties would be granted. The scheme would cost £34,700. The board was averse to spreading the cost over too many years, and wanted to avoid the burden of interest over a long period. The subsidy meant that £8675 had to be found by the ratepayers. The subsidy could not be secured without a prior guarantee of maintenance for the scheme, Mr Machin continued. The board thought that by spreading the cost of the scheme over eight years, lower rating could be adopted. The maintenance of the river was not going to be a cheap job. It could possibly be arranged that the maintenance costs did not overlap construction costs in the initial period. Ratepayers were presented with the choice of a four-year, six-year, or eight-year period for rating on the scheme; they were also asked if they were willing to be rated for it at all, said Mr Machin. The classification of ratepayers under the scheme had, he thought, been well and fairly done. The law provided a remedy if a pro-perty-owner thought otherwise. Appeals could be made to the Magistrate’s Court in Christchurch before June 24. Mr Machin warned that appeals could hold up the scheme and the subsidy. The board would be prepared to start the job in the belief that the subsidy was forthcoming. The Oxford to the sea drainage scheme had hung fire because of two concerted objections from Rangiora and Kaiapoi, he added.