SiLVERSTREAM

Evening Star, Issue 17311, 26 March 1920, Page 6

SiLVERSTREAM

PITIFULLY IViISMAMAGED. WATER RUM TO WASTE. Yesterday a party from Dunedin, including a representative of tho ' Star,' visited the Silverstream water supply system. The Silverstream ha« its source in the Silver Peaks, and is tapped for Dunedin supply purposes possibly half a dozen-miles above where it debauches from the gorge into the Taieri Plain. A race of over 19 miles long conveys the water from the dam at. the intako to the southernreservoir, the race for the greater partfollowing the left bank of tho Silverstream. The party yesterday left the- bed of the stream'and climbed to the race, reaching it, at about the beginning of No. 3 section. (For patrol purposes the race is divided into three sections, and No. 7> is that section nearest the intake.) A walk of nearly 40 minutes along the turf bordering the race brought the visitors to the intake. On the way up one noticed, first, the disappointingly small flow of water in the race; second, the amount of slimy-looking green weed which festooned the bottom of the channel in long streamers; third, the quantity of tutu, ronini, Yorkshire fog, and grass growing on the edge of the race, overhanging it, and seeding into it. Unquestionably the race is suffering from neglect. The only sign of recent | attention was the cutting of the grass along tho foot track. It. had been cut this season. I On arrival at the intake there was anI other surprise in store. The dam has j been allowed to silt up almost to the top. I The gateway admitting water from the ita-m to the race was open to a depth j (measured) of between 3in and 4 ; n. This allowed very little water into the rare. On the other hand, there were abundant evidences of seepage through tho dam itself, which also shows signs of neglect. Above all, through a vent at the bottom of the dam. a fine flow of water was discharging into the bed of tho Silverstream. In short, much-needed water was being run to waste. Along the race line sma'J feeders oniue from the hill above the race. Most of these are llumed over the race to run to waste down the Silverstream bed. One of these is. however, led into the race a short distance below the main intake, but the arrangements appeared so primitive that su?piei.'u of considerable loss could not be avoided. The other possible feeders v.i-rc mostly dry, but the nature of, the gathering ground is such as to support the belief that if an earnest eff-jrt were made to utilise them they would, even in thy weather, contribute something to the How in the race. Roughly speaking, halfway along the gjrge— i.e.. halfway between the intake and Taieri Plain—Powder Creek enters the Silverstream from the right-hand side. The race being on the left-hand side, the Powder Creek water cannot be got into it. iby gravitation. The City Corporation have, however, installed an electricallydriven pump in the Silverstream bed, } bringing the electric curient up the valley ! by a cockspur line from the V/aipori main i transmission line. The water is forced up ; a pipe line laid up the hill to the race. The piojcct. has cost a good deal. Not all I the-water pumped up this line comes from I Powder Creek. It will be recollected that | a good flow of water is allowed to escape j from the dam at Silverstream intake and j flow down the bed of the stream instead ]of along the race. This water, then, is ; available for pumping by the Powder ! Creek pump. It seems a remarkable iu- | vers;:m of sound engineering practice to j waste the water where it could be im- ' pounded by gravitation, and afterwards to catch it, or some of it, and expend energy on it to overcome gravitation. This water could have run down the race from the intakes- instead of going down the bed of Siiverstream and then being pumped up into the race. The iiuost flow of water seen yesterday was in Flagstaff Creek. This stream comes from the western flank of Flagstalf, and outers the Silverstream from the left at Wh.arc Flat.. Its volume at the confluence was such as to suggest that it must have been fiumed in to to over the j race, which its course crosses at abjut right angles. Curiosity took yesterday's | party up-stream to the intersection, and | it was well rewarded. A comic-opera J attempt has been made to impound Flag- J staff Creek and lead its flow into the race, i A miniature dam of puddled clay a few I feet long and a few inches deep has been | built. Its erection represents the equiva- [ lent of a busy and interesting morning's ; play for a couple of children, its effect ; is ludicrous. Only a tiiekle is led into the , race: the bulk of the~ water goes gaily j bounding down the bed of the stream. It merely percolates between the boulders ! underneath the toy dam, and "gangs iU \ ain gait." doubtless to the joy of" the j angler, but not to the relief of" the Cilv j consumer. In contrast with this, the party camo upon two men engaged on some hydraulic I work on a feeder coming into the' Silver- j stream from its right bank some distance I h ; gher up. They explained that this was j |Musgiel's supply, and that it was proving ' just about equal to the demand. They I stated that, as Dunedin was in such strait's I I for water. Mosgicl had treated the City.' generously, by forgoing some of her rights". | At small expense Mosgicl lioiutiah has j i installed an efficient system, and the. sap- j ply so secured is not only .sufficient in. i|itantity. but is of particularly good! j quality for domestic, use. its softness as j I wcli as its purity being noticeable. |