SILVERSTREAM SUPPLY.

Evening Star, Issue 17313, 29 March 1920, Page 6

SILVERSTREAM SUPPLY.

TO THE KDITO 1 " Sir.—lnstructed by His Worship, I have to to the points raised an a leader b- the 'evening Star' of March 27, as under: , j The 'Star' suggests that the sewage) pumped at Musselburgh is a measure of the water used in the Citv. If we had a separate system or knew how much water is allowed or forces its wav into the sewers this would be so, but under present circumstances it is quite useless. The sewaee pumped in dry spells averages 6,840,000 gallons * day; while at the same time,,unuer seveie restriction, the water used is lew than half this. The difference is made- up by water from many source that should never have been allowed into the sewers at all. Some of it, as infiltration into the aeep sewer, cannot be kept out. Anyhow it is the last- resource any sensible person would fall back on to measure the water simply. It goes against his own argument, and makes the consumption about double what it should be. The ' Star' then falls back on Mr W. N Blair'* report of 1877, which gives the predicted minimum flow of the Silverstream -roper at 2,100,000 gallons a day. This i-* another argument of'last resource. Mr Bkir's predictions were hopelessly disappointed 50 years ago, as the reports of ~S,lr Ahrams in 1890 and of Messrs Mirams and ITr-- in 1895 amplv record. In 1895 these "fliitlemen reported: "The reason that 'he Silverstren-m fails to fulfil the results expected bv its exponents is, in the first ' an exaggerated estimate of the Waiter available for collection by the race and the absence of anv storage accommodation." So that ghost was laid 30 years ago. The article speaks of a 40 days' drought. One cannot say what is meant bv this 40 days' drought. The present fine weather began on January 15, and has lasted, with occasional showers, fogs, mists, and dew for 72 days, bringing the flow of the Silversteam down to less than half a million —■lions measured yesterday, in place of the 2,100,000 nuoted' by the"' Star.' On the other hand, it is quite true that with the magnificent storage in possession of the City of Liverpool we could handsomely solve our problem with the catchments we have : but what sense is there in these absurd references? You might as well -"to the Scotchman who said : "If yon had Loch Lomond in Hell you could' sell it at a pound a drink." The 'Star' then refers to the lining of the race or pining of the race. 'This is very desirable in the interests of purity, but it will not increase the supply, which has proved a hopeless disappointment for the last 50 years. (Se» Mr Hay's and Mr Mirams's peporia.) The cost of the Lee Stream scheme is then attacked. One resTeta there is not a modern Muses who could smite Flagstaff and produce a. liberal flow of clean water "ratis. This, however, cannot now be done, and we must pay for a supply. Tho cost of the Lee Stream water will be about td a thousand gallons delivered here. Who will c-vudge that?—l am, etc., W. D. R, M'Cttbdtf., City Engineer. March 29. TO THE EDTTOK. Sir. —For obviously official reasons I am compelled to depart from my general rule of ignoring newspaper correspondents such as "H. V. Freeman,'' who writes on the Lee Stream proposal in your issue of this j evening. In criticising the contents of a circular I signed by His Worship the Mayor and the Town Clerk, Mr Freeman expresses surpriso that we should have attached onr names to " such misleading statements." One of these "misleading" statements is that the waters of Lee Stream could be piped to Roslyn; and this statement is misleading, according to Mr Freeman, be cause the hill reservoirs " are at a hicher level than the Lee Stream outlet." are the official figures:— * Lee Stream tunnel inlet 9Coft, mitlot 865 ft, Roslyn reservoir 7441't, all above city datum. So, after all, tho City Engineer has not "solved the problem of running water uphill"; he is simply making use of an elementary hydaulic law known to every schoolboy. If it suits Mr Freeman to express that law by asserting that water is being made to " run uphill," well he is J free to do .so, but the expression is a clumsy one nevertheless. Having shown that this so-called misleading statement is based on a demonstrable fact, I haveneither the time nor the inclination to deal with the other assertions in 2dr Freeman's letter, save to .say that most of them could be disposed of in an equally emphatic way, as, for instance, "Two and | a-lialf million gallons daily enter tho race (Silverstieam), only 1,C00,0C0 reach the reservoir." That is Mr Freeman's statement ; here is the fact : To-day, 1,000,000 gJlons cf .water, including that pumped from Powder Creek, enter the 'race, i 1-000,000 gallons reach the reservoir. I -Mr Freeman concludes by stating that I his former statement—that the Lee Stream I proposal would cost £3oo,ooo—is not chal- | lenged in the circular. Let me remind Mr | Freeman that the Americans have a defiuii lion of an engineer as a man who is c-a-I pable of doing for Is a certain class of I work that would cost- "the other fellow" I 2s. The loan proposal is for £162,000, ! based on the estimate of Messrs Hav and M"Cir.-dic ; therefore Mr Fiecman Ls entitled to raise his £500,000 bv another £24,000 to provide for "all factors of ignorance," and still keep himself within the American definition.—l am, etc., Town Clerk. March 27. TO THE EDITOR. Sir, —The ratepayers of Duncdin will be well advised to vote against this proposal to-morrow. (1) Because we have 56in c{ rainfall available every year, and waste most of it, ' ' " (2) Because. £162,000 will not complete the scheme. (5) Because we can secure enough water at a veiy much lower figure by increasing our storage reservoiis. (4| Because Lee Stream is not- pure. (5) Because the Cost of Living is high enough wiuiout increasing the rates. (6) Because I,ee Stream meajis heavy taxation. —1 am, etc., R. fcj. Black. March 29. TO THE EDIT OF,, Sir. —The water supply of our town has burni under discussion for some considerable time, and we seem no nearer a solution than ever. After reading your account of a recent visit to the above, one can scarcely expect, under such conditions, to get anything like the iui] benefits of this supply. It does seem a bit Irish letling the water pass the intake- for the eake of keeping a pump working, wasting time, also money and electrical energy for what could be easiiy avoided. One would think that a gaugo would bo placed iu position so as to allow Mosgiei's water to pass, and any -overplus to How iiuo the iSLlverstream race. There has been a suggestion of piping the 'Siiverslream How ; uut our citv neer says tiiat the water of such side streams would be lost. Nothing of tho kind. Aii that is warned is to connect, a feeding pipe -to the main lines, such feeder to be oi suiiicient heights to eorrespond with the tall from tha intake, lake, for instance, the first side siream, which is haii a- mile fiuai the intak'e. The fall from the intake to ibis sido stream is 6ft, and, according to your account of weed and green slime in the race, it is not 12ft to the mile, as anyone of experience knows that this only grows in siuggish water. Continue up the face of the lull or guily until you get, say, 101b of pressure. This will overcome the difference between the intake and the level of the pipe line, and will give about ljlb per square inch at tile junet-iou of the feeder with the main line and a* the line continues so will the fall increase; and Xo. 2 will have to be taken up to correspond with No. 1 feeder, these feeders to bo of such size as to take in j three or four times the ordinary supply, i and so get the benefit of any passing nuns over the length of such a main pipe line,

I would think that, instead of wasting so much of the ratepayers' money in pumping at Pow/ier Creak, if such, were employed in pumping into the main leading to the southern reservoir, we would /s;et something for our money. W© all know there are hundreds of thousands of gallons of the finest water running to waste under our feet, and this can be used provided there is the proper style of pump -used, fitted with relief valves and air chambers or vessels. I believe, the ] same could be erected in the converter i station, and so do away with additional expense in running. There is no doubt, of this being done, as I have had experience in pumping to much higher levels than the southern reservoir or Maori Hill. I am of opinion that a three-throw helieol geared plunger, purnp would do this readily, and that we would get sufficient oi the purest water without having to open a valve on the main for the sake of keeping the pumps at work at Powder Creek.—l am, etc, E.W.E. | March 29.