PUMPING DRAIN WATER.

Hauraki Plains Gazette, Volume XXXVII, Issue 5025, 10 September 1926, Page 3

PUMPING DRAIN WATER.

REPORT BI ENGINEER.

POWER BOARD’S DISCUSSION.

Mr N. G. McLeod reported to the Thames Valley Power Board meeting on Tuesday on the pumping of drain Water as follows :— “The matter off draining low-lying parts of our area by electric pumps has. be'efa exercising the minds ofcon- - sumers on the Hauraki Plains. Two pumps are already working and. more a ; re contemplated. “The results already obtained have been most encouraging, and it would appear that great benefit is. possible if due consideration is given to the yari- ■- ous factors involved. “Some aspects that present themselves are that' considerable capital expenditure may be- avoided, in the making and maintenance of large - drains; that the keeping low of the water in the drains improves the land and allows for considerably more storage of water ; that cattle can b‘e( kept on the land throughout the year instead .of being sent to the. hill sections ; and that the benefit derived by the pasture is such that a greater production is obtained from milking cows, one consumer stating it as his opinion that 1001 b more butter-fat could be obtained per acre per annum ' than is. the case at present. ■ “I‘have devoted considerable time to the investigating of this problem, but without accurate data as .to rainfall, run-off, capacity of drains, storage, etc. (and storage will be considerably increased by pumping), a definite proposition cannot be made. “It appears quite cejrtain that the pumps installed are beneficial, but whether they are of the most suitable siz£ remains to be determined. They are' not of the most suitable type. ? “The power supply side of the question is quite straightforward, and for any case within reasonable distance, df our line? the annual cost of running the pumps is comparatively little,' since the running time is. anticipated by the consumers not to exceed - about 600 hours per annum. “Meantime the pumps that a'ne. being used will provide most useful information. The total cost of each, including plant and housing completely installed (but excluding .power line and transformer station, which is paid for by the board), is from. £2oo' to £250, part of which was. made up in the. form of labour by the consumers concerned. If it is found economical to substitute new pumps for the type fit present in use. there will.be a certain recovery value in the old plant which would offset the cost of the new to some extent, so that what has been done would not be entirely wasted. “Terms are offered to the consumers df one-third cash deposit and the in quarterly payments! spread over two years, suitable guarantees' being obtained. Power is made available under special agreement at %d nett per unit for night' supply and l%d per unit nett for day supply. A minimum guarantee is required to cover this board’s liabilities oh-any expenditure it may make. “The matter is one calling for most careful consideration if the best proposition is to be obtained, and, in my opinion,‘should be dealt with as a whole by some properly constituted body, to whom accurate data and expert advice should be made available.’ The chairman said the position was that one pump had been installed and . others we.re contemplated. He had come to the conclusion that it would be advisable to investigate the position, and had accordingly instructed the engineer to report on the matter. Mr "Willy asked if it would be possible;'for the board to give the settlers '' definite information as to the type and cost of pumps.. The chairman said that it was advisable for a competent authority to undertake the scheme as "a whole. , The engineer said that, conditions varied considerably. If he was given information concerning the amount of water to be pumped, the variation in the head, and the. distance ’from the point of intake to the; point of outlet he could write a specification. for a suitable pump.. He had Written to the Lands Drainage Department with reference to the propositions! brought forward by settlers; asking whether it was possible to use pumps at floodgates, and, if so, whether a standard piping arrangement could thereby be adopted. It the flood-gates, had a standard length between the inlSt and the outlet there appeared to be no reason why a standard piping system could not be used, whatever the height of the stop-bank, because the pipes could be put through the- stopbank and a check valve installed, ■ as would most likely be necessary. The best size of pump seemed particularly difficult to estimate on account of the number of variables. The size and state of the drains limited the amount of water which could be taken by a pump, and it would appear that a jpump- capable off dealing with 2000 gallons a minute against a static head of, say, -sft, would meet thfej average condition and be as much as the, drains could supply. Depending an the Sfize and design of the pumping * arrangement, the total head might be ten to twelve feet, though this: de- _ pended also on the quantity of water ' passed. With a lower head more water would, of course, be dealt with by the pump. The work being done by the settlers was largely in the nature of an experiment, and while they Realised that they might not be able to keep their lands dry during very heavy rain, they felt that thelmprove-men-effected by even the above-size numps was so great as to warrant them carrying on. Mr McLeod said that he had therefore asked for ah expression of opin■ffjon by the Lands Drainage Engineer ■fi as to the carrying capacity of the ; 'drains leading to the flood-gates in other words, his opinion as to whether the pumps in use were as large as could reasonably be used at each —-point. The drainage engineer had said that conditions varied so much that ■nothing definite could be said. Continuing, Mr McLeod said that the matter was. very complicated and

could not be treated generally. If definite information was supplied he could give the whole information desired by those discussing the installation of pumps. Mr Price said that the; engineer’s report should concern other local bodies rather than the Power Board. The matter wap drainage business, and this was not within the Power Board’s jurisdiction.

The chairman agreed, and said that the board’s engineer should not spend a large amount of .time on investigating what was' the business of a drainage board or a group of settlers.

On the motion of Mr Price it was decided that a copy of the'report be sent to the. darinage authorities operating on the Plains and to the Commission which would sit at Patetohga riejxt week.