NORTH SHORE WATER.

New Zealand Herald, Volume LXVI, Issue 20174, 7 February 1929, Page 12

NORTH SHORE WATER.

VAGARIES OF LAKE PUPUKE.

RECORDS OF RISE AND FALL.

INCREASE IN CONSUMPTION,

While Lake Pupuke, the natural reservoir for the wal-ur supply of the four Waiternata borougha, Devonport, Takapuna, Northcote and JVirkenhoad, docs not tin's summer show as copious resources as Auckland can boast in its Waitakero dams, it still has excollent domestic reserves. The level of the lake when the latest records wcro taken, a week ago, was nearly tlie same as at tho corresponding date last year. In (ho nieantimo an alteration has been made in tho method of recording tho lako contents. Tho system has always been to stato them in comparison with tho mean high-water level of Rati gi to to Channel, but the datum lovel as to high lido was different as between tho boroughs and tho Auckland Harbour Board. Tho correction has been in tho direction of making tho municipal datum conform to that of the Harbour Board.

On last week's reading tho water stood 14A- inches abovo that of tho channel, which approximately corresponds with six inches in tho caso of tho old datum, the lovel shown by tho record for tho end of January, 1928. Tho highest levels recorded in tho last few months wero inches, at tho beginning of October and 28 inches on tho 15th. From this there has been a gradual fall under tho influence of tho sulnmer consumption and tho dripr weather, amounting in ono period of seven weeks to inches. It is estimated that an inch of riso or fall, calculated upon tho whole area of tho lake, represents a total of nearly six million gallons. Tho daily consumption of water iu tho four boroughs, for domestic, sanitation and other purposes, is nearly a 1 million gallons. A year or two ago tho drain upon tho supply in Devonport was higher than at present, tho reduction having 'been brought about through tho installation of meters, and charging upon actual consumption, thus instilling habits of economy on tho part of householders. In tho distant past tho level of the lake was much higher than at tho present time. This, however, was before tho growth of Takapuna as a borough, and beforo the sister municipalities had risen to anything liko their present proportions. In 1892 tlie records show a level (upon the old datum) of 7£ feet abovo tho sea. In 1893 tho increasing consumption of the boroughs brought it down to five feet; then it was lowered to four feet, but liberal rainfalls brought it back in winter to tho neighbourhood of seven feet* Sinco then, with tho growth of population in all tho boroughs, there has been a more or less continuous fall, broken only by short temporary rises, until the lake has come to tlie present consistent level of between 13 and 14 inches, calculated on the new datum.