BIG DRAINAGE SCHEME

New Zealand Herald, Volume LI, Issue 15562, 20 March 1914, Page 9

BIG DRAINAGE SCHEME

LOWERING WAIKATO RIVER

ENGINEER'S STATEMENT.

RESULTS OF INVESTIGATIONS.

Ihe two engineers concerned in the Waikato drainage scheme, Messrs. Thompson (representing the Government) and T. C. Kennedy (consulting engineer to the Waikato River Board), have held a conference this week, for the purpose of discussing certain points, in regard to which their respective reports were in conflict. Mr. Thompson is forwarding a report on the subject to the Government. Mr. Kennedy, at the request of the River Board, met the ratepayers interested in the Mercer Hall on Wednesday evening, and supplied them with a great deal of interesting information regarding his investigations as to the feasibility of lowering the level of the Waikato River, and thus providing drainage for a large area of low-lying land. Mr. A. G. Glass presided. -Mr. Kennedy stated that since he had made his last report Mr. Thompson, at the direction of the Government, had taken levels and tidal observations and made surveys, thus making the data far more complete. Mr. Thompson's work had been carefully carried out and checked, and might be taken as correct. In referring to the two sets of water levels, he said that from the heads to Taranganui (between which places the real obstruction, in the river existed) the difference was not great, being less than 6in. The low level could be considerably reduced by removing the shoals and improving 'flow by controlling the width of the channel. On the completion of this work the possibility of, draining adjoining lands and securing a partial, but a substantial, immunity from floods would follow. There was evidence to prove that many years ago the bed of the river was lower by sft of 6ft above Mercer. . The bottoms of the outlets to the various swamps were quite that number of feet below the present river bottom ; formerly the levels must havo been the same. Tn recent years erosions had taken place. Vnd islands had been formed, and i...e shoals below had increased. By reproducing a condition of the river channel similar to that which existed years ago, the level of the river coiild be lowered. The low water level at Tarangamii. six miles from the Waikato Heads Wharf, was 4ft higher than, at the latter place. The river below this point was very wide, bait if there was a channel of reasonable width and depth it was likely that a low ebb tide, with a very small low, would be carried up to that point. There was no engineering difficulty in providing such a channel. Mr. Kennedy said he considered that another 9in could be saved between Taranganui and Devil's Elbow, and an improvement could be effected at Lapwoods Mill, if the works already recommended by him were carried out there should be an effective lowering of 2ft 6in at Lapwood's Mill. He considered that nearly another foot could be added between Lapwood's Mill and Mercer. He advised them to carry out that part of his proposal affecting the river between Kaitangata and Pakan. If no action was taken the position would become worse In reply to the chairman, Mr. Kennedy stated that if funds were short it might be advisable to cut out the stone groin work and substitute ricker groins This work, however, would only be of a temporary chapter, and 'he" would prefer permanent work being done at the outset. Ihe probable cost with the stone groin would be about *u2,000. The works would not be detrimental to the Ake \ke lands—probably the reverse.