FEW DAYS’ SUPPLY

Gisborne Herald, Volume LXXIII, Issue 21935, 1 February 1946, Page 4

FEW DAYS’ SUPPLY

BOROUGH WATER

RATIONING IMMINENT

SERIOUS PRESSURE FALL

“By skimping we will be able to make Uie present supply of water continue to meet the tlomcstio requirements of the borough for a few days yet, after which unless relief has come, we will have to introduce rationing,” the borough engineer, Mr. G. F. Clapcott, stated this morning.

Th? supply at Mangapoike has dropped to the extent that only 8} hours' pumping per day is now possible. The Waingake Creek supply also has dropped to an alarming degree, and part oi’ the supply has been coming in from a pond in the creek three miles below Waingake. The pump operating at this latter source broke down about 7 o’clock last night, and was restored this morning, but the breakdown caused a reduction in the supply. “The only thing we can, do in the meantime is to study the greatest economy and I am pleased to say that, generally speaking, the public is doing this, but Ihey will have to go still further if rain does not come,” Mr. Clapcott commented.

Fall in Pressure . At the moment there was sufficient water to keep a limited supply to consumers going, but the difficulty was to maintain pressure, and the result was that when the pressure did fall below a certain level residents situated on the higher ground were unable to get a During the peak periods the pressure now falls as low as 101 b., while in the normal way the pressure at peak periods is between 40 and 501 b. when there is a full supply at the headworks. From 7.30 to 11.30 o’clock in the morning there is the biggest pull-off, then the demand eases off and the pressure starts to rise, to sink again between one and two in the afternoon when the demand increases, then it gradually cases off until between four and five when the third peak period of the clay is felt. The morning pull-off is the one which is causing the council most concern for it is then that the pressure reaches its lowest degree as there is no weight of water at the headworks to maintain it. There is no reserve supply the council can fall back on if the present source peters out. and how long this will last is indeterminable, but i tis known that it cannot last much more than a few days. There appears to be a capillary attraction in the atmosphere to draw the water out of the river bed. and this maintains the level even though there is indeterminable, but it Is known that natural action may stop suddenly and bring about a further drop in the creek levels. , , , , This action was illustrated last week. For a start the council was able to pump 20 hours a day, then as the level subsided the pumping was reduced to 18 hours the next day, the following day saw a further two-hour drop in pumping. while on the fourth day the level had gone down to the extent that only 12 hours’ pumping was possible that day, a matter of a 25 per cent drop in 24 hours. These figures give an indication of how unpredictable it is to say when the supply will give out as there is no definite guidance on what pumping will be possible.

Evaporation is claiming a fair quanity of water as the hot stones absorb the moisture and help the sun's rays in this direction. All water coming into the borough, both pumped and by gravitation., is now being chlorinated, but even with that precaution the Department of Health strongly recommends that water for drinking purposes should be boiled first.