SULLIVAN'S DAM

OFFICIAL OPENING. On Saturday afternoon Ct' Wilson (chairman of tho Water Committee o 1 i'io Cit> Council), accompanied by his Worship the Majoi (Mi J. .J. CLuk), and liie othei councilors and! tneir wives motored to the icccntly coiripleLcd Sullivan's bam, so called after ex-Councillor A. J. ti dhvan, who initiated the proposal to construct this dam and taw it well on the waj to completion beioro ho lesignod tiom tho council. Tho occasion of Saturday's visit was the formal ceremony of turning on tho water. Tho Mayor presided ottr the gathering at tho dam, and called on Cr Wilson to address those present Cr Wilson referied at tho outset to tho original proposil to construct the LeithWaitaka scheme, which utter being investigated, was abandoned. Mr M'Curdie then investigated the present site, and plans for a smaller reservoir vvero picpared. On Juno 2, j.909, authority was obtained to proeoed with tho work, the Government stipulating that tile reservoir should not bo more than 30ft abovo the town. Plan o were submitted to the Public Works Department, and wero approved on September 7, 1910. By Order-in-Council, passed on March 21, 1911, the City Council was empowered to carry out the construction of tne dam. Tho dam h.id been called Sullivan Service Dam, after Mr A. J. "Sullivan (ex-chairman of tho Water Committed) as a fitting recognition of his ablo services to the city, particulaily in connection with tho Water Department. It was not until February 20, 1913, tliac authority to construct tho dam -was ga/etted, and' the work was not commonecd- until May 16 of that year. However, it had been pushed on steadily, and had been completed this month. _ The orig'nal estimate was £22,0C0, but thority was obtained to spend up to £25,000. Then an extra amount was granted to cover £3000 increases in wages due to a new award, and tho dam was completed at a fetal cost of £2'/,000. The whole of tho material, with tho exception of tho iron work, had been prepared by th<> corporation employees, tho result being a considerable savmg to tho ratepayers. Tho dam consisted of a ccntral core wall of puddled clay, averaging 12ft thick. This puddle core was down to solid watertight ground to a depth of 34ft below the surlacc Above tho ground tho puddlo core was carried to the top of tho embankment. Tho embankment on each side was made up of stone and clay in tho proportion of two loads of stono to otje load of clay. Tho puddlo core was rammed with hand lammers and tramped vvitji men's foct as tight as possible The stono and clay m tho embankment were rammed -with power rammers till each laj'er of sono camo in contact with the layer beneath the clay, merely filling tho corncrs. Tho mam body of tho embankment was therefore a sort of masonry with clay mortar, and would not subside, and would be very difficult to damage. Tho face next the water was pitchcd with rock; and near the top, whero waves would give mcst trouble, it wasiaccd with concrete flags. A storm channel surrounded the reservoir for the purpose of catching dirty flood water and keeping >t out of the drinking water. This channel was proportional to the amount of water that would run into it. It was mostly lined with concrete, and was capable of taking care of a. downpour of an inch an hour otf tho whole aica above it. The spillway from tho reservoir at tho west end of the dam was capable of dealing with rather moro than an moh an hour over the whole catchment abovo the dam, so thfit should anything happen to tho storm channel in a flood tho spillway would deal Kith the water and prevent any flood from getting near the top of the dam. The water surface of tho reservoir was 13j acrcs, tho depth at tho embankment 20ft, end tho quantity of -water it hold some what over 25,000,000 gallons. An immense quantity of buried timber was icmoved in the clearing of tho bottom over the acrcs. Hundreds of stumps had to be blown up, and a great deal of labour was expended in digging up moss, roots, black earth, and other rubbish. Th s material was trucked to tho embankment on 'light railways, hauled over the embankemnt with electric geai, and tipped where it now behind the dam. The maintenance of tlic road to town was taken over l.y the City Council trom the Maori Hill Borough, when tho work began, to prevent disputes on tho subiect ot tho exhaordinary traffic caused by tho City Council's operations. This resulted in a steady improvement in the condition of the road, which was now m very good order all the way to tlie saddle. A storm water diain had to bo laid fiom tho saddle to a point below- tho dam. This drain took .ill tho washings of tho road, aaid prevented any pollution of tho from this source. Btsdcs the -water falling on tho 375 acres ot land in the catchment of tho dam, vvata" from 1300 of the heads of tho creeks m tho Waitati basin was brought into this reservoir. Tins watci \\a» caught in an earthenware pipe hue about two miles long, running along the lace of tho hills the bush. It was biought through the saddle in a tunnel, and turned into the Leith, down which it ran into ihe dam. Some of thib water was caugiu at tho saddio and biought down to the embankment under pressure in a 9 inch ca«t iion pipe. Tliis pressure was uood to litt tho water from the lesei voir ov-er (iic embankment. It was used to empty resorvonx by a pipe oi tunnel thiough the embankment or by the embankment. This wa--always a source of weakening and clanger. It was calculated that about 90 per pout of the failures of caithcn dams was caiu-rd by tho failure of tho pipe under tho cm bankrnent, or through leaks developing about the pipe. 'lhis souicc of weakening bad been avoided in the dam by jetting the water over the top ot the embankment It was believed to be tho first caie of "(he kind on itcord. Tho work had bem c,u ncd out m a most creditable mannei by the engineer (Ml M'Cui die) and his assiotan*Mr King applied labotu-sav mg appliance to a numbei of ways, and it was a ercdic to tho department the way tho men had been housed and cateied for There y,,-. lirewood m abundance for thorn, and (h - elretiie lip lit was put oil to their houses and they were provided with a social liall Cr Wilt-on then called on the Mayor to tuin oil the water, which he did amid applau-i-The p.irty then lcpaned to the big soci d hall foiniei!\ u'-ed bv the men, whcie the weie entertained at afternoon tea, which piovcd irio-t enjoyable. Cr Wilson proposed the health of il r> engineer (?vlr M'Curdie) who. ho said. « loa\ing on a trip to. Australia on Wedii" dav He said, their engineer had bee> ciitieised veiy hardly and in many pa*-, i nniMcsir,'' TtU'v -"oul i nidge a inin h ln\ workf No>v and agiin there had bo<; (hfitreq levelled ngninst him which lied h-rn, proved to bo without foundation I!> wish'xl Mr M'Curdie bon voyage and a saf return. Mr M'Curdie suitably acknowledged tin compliment paid him. Tho party then returned to Dunedin.