THE ARAPUNI DAM.

Evening Star, Issue 20019, 9 November 1928, Page 9

THE ARAPUNI DAM.

TO THE EDITOB.

Sir, —Will you kindly permit me to reply to the remarks which have been made with regard to my letter calling the attention of the public to the :potential danger in connection with the very high dam which has lately been constructed by the Government across the Waikato River at Arapuni? Mr Furkort. Hie gentleman who is solely responsible for the stability of the dam, as he was in charge of the construction and passing of the foundation when excavated, has remarked that I am getting very old—this is not the first time he has made such a statement—and have forgotten the circum: stances in connection with the dam. 1 may, as we all are, be getting old, but T am not yet seventy-five years of age (by several years), as stated in the Auckland ‘Sun’ of the 27tb-ult., and I have not yet forgotten the facts upon which my opinions seventeen years ago were based, when I rejected all idea of Arapuni as a dam site, and again in 1917, when I strongly advised the chief electrical engineer to abandon Arapmii as a practical site for a high dam. This advice was given verbally and in writing. My opinion of the potential danger of the undertaking has been known to many of the public for years past, some of whom reside in the area threatened with disaster. On September 28 last some information came to hand which confirmed my previously-formed opinion of the country, which placed the safety of the works in such a perilous plight that I requested my sop to immediately inform Mr Downie Stewart of the position, which Was done within half an hour, and confirmed next day in writing. This relieved me of all responsibility by placing it upon the shoulders of tho Government. Then, ns no action was taken towards an investigation of the condition of the dam 1 determined to publish the letter which 1 wrote.

Tho time and manner of its publication have nothing to do with the question of the dam. Statements have appeared in the papers savouring of personal attacks, and stating definitely that the dam is quite safe. It seems strange that tho responsible Government of a country like New Zealand should have to descend to making personal attacks on a fully-qualified engineer who publishes his opinion of the unsoundness of one of its undertakings, and on being warned go to the men responsible for the construction of the dam and ask them if their advice is any good or uot. They would bo the last people in tho world to say things wore not as they should be. Judging from tho information to hand it appears that nothing is known of what the foundations under the dam are like a' foot or two below the _ concrete_ work. In country like this, when intending to construct a dam 200 ft high, bores should have been put down at least 300 ft, or until solid rock, not breccia, was encountered and j)roved. If the Government has the necessary information, why was it not published on September _ 29, the day after the warning was given? It has been found by a bore over 200 ft deep that only sand and silt exist under the powtr house. Note the following quotation from the contract specification:— “ The rock at the site of the power house-da a tufa, of volcanic origin and of moderate hardness, but may include soft layers or pockets.” Any country containing even a suggestion of soft layers cannot possibly bo accepted by experienced engineers as safe country in which to construct a dam 200 ft in height. This is not an ordinary dam, as 'usually understood by the general public, but is classed amongst the highest dams in the world; therefore everything about it must ho above suspicion. Perhaps the public thinks the dam is pnly as long as the concrete work across the gorse, about 300 ft. but owing to the shattered character of the country, and the present flood and overflow channel being situated along the top of the cliff a short distance" from tin edge, it must be considered as being over 5,000 ft in length, over which distance it may fail anywhere. No undertaking of the vastness of Arapimi Dam, and containing so much potential danger, should be constructed on a river above an area of country so extensive, or that contains such a large population as the Lower Waikato, and most decidedly not_ by a Government, the members of which are elected and paid by the people to protect them. When the foundations were ready for building upon, the passing of them as being fit should not have been left to one engineer in this case. A perfectly independent engineer should have been called in as a consultant,_ preferably one from outside this dominion; subordinate engineers in the Public Works Department could not act as consultants, for very obvious reasons. _ In conclusion, I wish to mention that no amount of statements by engineers and others are of any avail unless supported by absolute proof. Suclt proof is not in existence at the present time. In every newspaper which comes under my perusal I expect to read news of some accident to the dam or contingent works, if not of a tremendous disaster.—l am, etc., B. W Hoemes. T. 5.0., M. Inst. C.F. November 6. i i | j