WATER FOR AUCKLAND.

New Zealand Herald, Volume LVIII, Issue 17894, 23 September 1921, Page 7

WATER FOR AUCKLAND.

POSITSON UNDER REVIEW.

PROVISION FOR FUTURE.

Tim SCHEME FAVOURED

WORKS TO FOLLOW XIHOTUPU

The whole matter of the city water PUP!':* I" rrl.ition to present and future , —is was lie fore th<> City Council last -V- we rh« Mayor. Mr .7. 77. Onnson r-porird i)|v,n a recent visit paid bv him 7-i ompany with the chairman of the Work* Committee. Mr, G. Baildon . i.v enpnw. Mr, W. E. Rush, and the "ngmeer. Mr. ,7. Carlaw, to fh " U P> wnrk ""- said that work at the large new reservoir was proceeding K-tor.ly. Providing tl at the present proc , >.-- was contiruled this work should t" :■ Vd in May. 1923. It was therein ■ ie«ir that substantial additional yter , i.'rage was assured by the summer •i :■ «ur. T.r.s leit tie council with i-i-M s'i'jinier t.> meet, bin there was no ~ ,,r ani'cmaimg that the council ' a ! •■•""i-.n of greater diffi " *ua.t whiih had confronted it r«.v»'nt v ears. :

" It would seem that the time is apt- . : for a re summer t of the coun- - . ••••■>' in resjv>, t ,-.f xha water supply r , ' ". s . \ n K.land and district " l r . '' UTls,, n. The Waitake're iKleqnat.- conservation ysir-~i unj* pro\"i. e :1 1l t'he water that Hie r_!v requires for some years to come. ■.e 71 should he next developed, and »-rvdd he now taken in band and a de>si n nude as to h"-w it i« to be dealt ' h - rt that it be a n oit completion of •,e r -esent._ works' at N'iho'upu. It is the *st AaterSi.- 'd and stream in the ranges, dcv, ! ;Qm, '" lt will not commit the ." ' ' ° t:V> ""ore extended proposals the .-.ity engineer.

The Like Taupo Proposal. i<-> the suggestion concerntr termed a permanent supply '■on; Lake Taupo. these proposals are " n ' ,e coun, ,'l' s re ' OI "ds show that " .ir t .mo to tunc Ibis permanent supply ci nsidered. It w U be seen from r ' ?■ ,r t fr >Tii the «rorka. engineer, .''■" i '<M. '.hit' financially the proposal is practicability at present. The n ' n he different, and irrespecma * ter .tf wt would have to • r i' the coui:. J had not an adet '»■« >*:d supply much nearer at an. No reasonable jround can be advance.) tor sen, 'lslv suggesting the undertaking oi «"d the heavy financial obligations involved in •on recti on with the Jake Tau po source of supply t which, taanciaily. may be summarised as under: M7N rMT'M CAPITA!, COST *3.000 000. Or £ To sjinoa! 6 pc-r oent... a-nd sinking fund, 1 per ten I. . . QIOJOOO ( ost of a.-drnt:ustr*t.ion . . . 16.000 £•225.000 c ' £ j w-Aif revenue on protw it t>asi« 80,000 other a-ut bonne®. Wa.i----s-aio --.nri town, say 35,000 '.~V-ac :ec.-y r«r itctm .. .. 110.000 £235.000 Tie li-wi'iil loss oi £ llt .000 onder the oest returns from the Taupo proposal •*ould be increased by the debit for terest and sinking fund en present loans, I w cich would becr.-tne non -evenue earning, but for the purpose of 'his statement have it been regarded, though such would make the loss h«vn'r To meet the vea'ly deficiency of £110.000, the water charges would ne«d u> be increased 100 p«r cent., or au add.tional rate of '

Is 7d in the £. annually would have to j f'r. imposed on the ratepayer.-, to meet i 'he cost. In present cordi'.ions the pro-! is nr.v.ananted. j ■ If the time dwi lorat when the water , supply from the ai'akere Ranees is in- ' , "uibcient, and wheu it. :« s-.iccested that, 'he citv corporation has ;m < nligation to : , ™-operate with other Uual auihonties ot 'he Auckland Province 'n the matter of - permanent and adequate supply of ! water for the whole territory, then pos-1 r-bly the time will have arrived for the; Taupo proposal to be considered, , but that period is probably several de.ades in the future." ! Population to be Served. j Attached to t.be Mayor's report, was: one iiom the city engiueer dealing ex-! haistively with the whoie question. Mr Hush set out m detail a scheme for the fall utilisation of the Waitakere Ranges] ;j.« a source of supply, which he submitted after surveys had been made in 1915-16. ! Mr. Bush sajd it was early recognised dur- j' mg the surve-s that the si utherri section of | the ranges offered th* greater advantages | ■■iv. i future source of water supply, first ; b"Kause it. L-. nearer tho city, and, sec--;>diy, as it lies at a much higher elevation th?.n the northern 'section, thus enabling i large portion of its v <-|d to be jravi!_aL.*l The report proceeded : — ! '' In anji.'fnn;.' the nee«:ls of .Auckland in i be matter of water supply it is necessary first to define the possible area ; I/, be served and th«-n to e-timate the ; probable trrowt.h of population. As re- j -ards area. I have t-hat, the dis- i t net will comprise the whole of Eden ! -.iintv and inelud» also Otahuhu boroncrh j 'he east and New Lynn and Waiku- 1 on the west, a total in rou.id figures j 35.000 as-res. T pur.yoselv not tvluded the North Shore boroughs t>e- . • "-.use •]! an indenendent report has been 1 f'Tii.shed bv another engineer; (2) they would be served better from the northern ' portion of the Waitakere ranges, and the ! & hfrrtf now submitted deals with the (southern ; (Ti the harbour forms a geo- , rrarhieal boundary whi.-h from both an —.gireerinz and policy view cannot be ignored and if the northern boronchs can s cut t.heir own salvation in the mat- i f <-r r f sunplv it is murh letter so. " The following table, gives the estire - .pu 1 ;ilion and quantity of water ; r<-qu:ie.j ter diem at 50 gallons per capita j ' r par-h starting from the year j ' ■ v'o Popt.la. on Dadv Biipply. V'xrhci Tf of Mdhons fjt.i- North SlK>re.) • f Ga.Hcri.el':t26 . . . . 1. : .9/iOO 8 I")''.': .. .. 2 L 1 .'K"C*t 101 I 154.') .. .. II ; !'• c. . . . . 3''■:'!>) is; | ijui . . . • 4'jo,'M -ii i ' I'he consumption of wat- r per capita i can ir.lv he assumed r.r:d protoMv rnay S ox i 'he fir':re of IA gallon?, taken, but ; on'., 10 per < ent must added, i ■' if. •( 20 per cent, to the figures <•■ supply recjtii-ed. Present and Future Supplies T.revfnt -ur es of supply are: — 'A • ic:ere ha'in;- a st'-ra'.'e reservoir "fj.iy/t j.'aii- r.?. and vicslditig not t 'i 3 <y?].ijf}o d iiiy- (2) Nihotupu, j .•■■■' < v,! icn i> now being irn- I v , at to Ft.-ue 540,000,C0 gal- | i e-••mated t .- vu-ld 5,000,000 •o 6.600 CO gxilons drtil'y. 0 ( West»ti Jjj-r-r «•-, yielding 1 -iChCO gallons 'la.Tv. (;r:< hur.; a, Mannkau, (Jtaj. M .:.n: Albert. Muunt Roskill, • : r -j if- : 1 gallons daily. " Trea'\',"e:-ter T i springs and the i ' 1 ' r pun:i j :.tr , i > r pi purely erner- ., . ■;j.-1' cj, j; id I b» s"er, that with I • .- i i.e.; If' n . < tie N'h 'tupu Si'lieUie i - • » : . . riiv enr.'ijrh provision to last the '■ • -j. i i : i■ o>*r it ;ev. tdl 1926 at 50 cal- ' st • t ..ip'.i. and - ti.- need for further ! * ' -n be. i i:it- < ppurent. '' J . , .... nein' 1 J i. i \ e t.". pr'.po.st, for ■ h-u-t-.'-r 'a'.i.-it of the present, supply, .--id • ;i. r demands of the future, 1 ! j ;•• i in'-r'-eiit ;or. <-.f ail upland 1 •R.,"/al. -ve a gravitation line between N ■ -, : j aid Karekare valleys, and < »acgi' u i" noight between 370 ai d 400 ft. 1 it, ■ t m. m I'd . by an aqueduct 1 U i er.gth between the j i P"i't.o ■ ,rn'-.] and th"nce into the city 1 wi. •! r T h", ri>iles. making 30 miles in all. f • >. The eon-tmction of storage p>,ser- i ir. the Huia, Karamatura, VVhatipu, 1 farano i. and Karekare valleys, so as to i r'.ilt?.e to its economic limit the yield of s •' 1 :e• r ff? p... tive gathering grouuas. \

th ft tocP 16 fart > e r u ' tlma te utilisation of v^!levsT CeS H° f the iower P° oTthe storage r puitable points, and lnthe w,u P um pina machinery to lift ffravitaf r mBU reservoirs to the k a i ta^ on aqueduct. tho escribing the aqueducts which would Bush 6 said^th UIK ' er ' us Hnia scheme Mr. at a f / e main 0116 wou 'd commence ?h„ „ P . , 80m ® two or three miles to I< would °hJ ha Khyber Pass reservoir. deliver 20 «*» fWvT ul , t , lrnate J opacity to Z 00 P- 000 gallons daily. The ' would Wee, i l the dt >' Huia T,, Lr 13 1-3 miles, or 70,400 ft. W needed L?' ° mil ? of mains w °uld be , needed to convey, the water to Khvber hut XT™, J™ the eild of «>e ««it, and another two miles for a branch pipe from the ma in aqueduct to the Huia a nd h \VhT nd Sf :r ,iun between tho Huia and W hat> pu valleys would bo of a cat>a city o 14,000.000 gallons dailv, and a total length, of 7.43 miles. the third vTllev.w wT" > Vhati P u and Pfirsraha xalleys would be of 10,000,000 gallons capasecti'on" K J ,Tlll f ln Ien K th - The fourth section between Pararaha and Karekaro ™* i&\°Ls s^ 000 KaUona capadty: Six storage reservoiis would be req ired under the scheme, exclusive of poss'b'y a small one on the Kakamatua. lirst- to be constructed and the most important would be that in the Huia Uon ,e of a 49-f ble Kl6 eXl:stwl at an o'eva,of , ; lb °vo high-water mark. , 6 uO'K"' of this dam would be 110 ft 2030\ S r ream le !. ei - , {he area of i , acres, and the amount of water impounded 440,000,000' gallons. t„™ h ° "T?v ld Would bo at KaramaUna, with a storage can&ritv r>f IOOOOD.OOO gallons; the third at Whatipu, *ith a capacity 0 f ,300,000,000 gallonsf6*™lll"*'l aL P arara h». with a capacitv ■ sixth w ? al, ? nf!; and the fift h and sixth would be m the southern and middle \alie\s of Karekare respectively, and impound in all some 240,000.000 gallons the Kakamatua reservoir, if conW, ald be of a capacity of 40,000,000 or 50.000,000 gallons a « the caUbment area, was only some 190 acres.

Proposed Programme of Construction. The proposed reservoirs, proceeded the report would have a capacity sufficient to deal witY) the whole stream "flow during a year of minimum rainfall, estimated as 4oin., and 60 per cent, run-off. This was equivalent to 1580 gallons per dav per acre of watershed. If reference were"made j to his table giving the estimated population and daily supnly required for various decades, it would be seen that the programme of construction required would be on the following lines. ' the figures given representing millions of gallons:— Estimated Supplies required: demand. to meet dem&nd. S Waitakere 3 Nihotupu 5 ]936 10i Kakam atua .31 Huia 341 134 C 1 < X a-ramatu ra .SO 1955 iq - 2.-8 1903 Pararaha 3.82 1960 ?0 Karekare 2.01 20.13 It must be borne in mind, said the report. that the figures for growth of popu--1 lation and demand beinr; only estimates j the programme of construction might roj quire to be acrelerated or retarded to : suit the actual demand. i Some 8.000.000 gallons daily could j be made available from the lower portions j of the valleys alreadv referred to, including Nihotupu, and the aqueduct could bo j ejuended from Karekare to Piha, Wekatahi and Marowhara valleys- These vali leys would yield a further 4,000,000 fco 5.000,000 gallons. ! Advantages of the Scheme.

Ihe of the scheme were summed up by the engineer as follows :— (1) It offers by gravitation a supply of water of excellent quality and sufficient quantity to meet the city's wants for 30 or 40 years to cotr.e, without necessari!v resorting to filtration, and possibly capable of extension by adopt'ng pumping for the lower areas. 1.2) It proposes to utilise lands of little or no use for agriculture or grazing, and so preserve them for all time for their proper function as scenic or forest reserves of great beauty and great usefulness for water supply purposes. ("3) It lmpc.ses its financial burden more or less gradually, and in proportion as the incoms from the e.apply of water will be capable of meeting it. " (4) Apart from the payment of interest and repayment of principal it will be an inexpensive scheme to maintain. " (5) It will provide emDloym«-.nt for men m the immediate neighbourhood of Auckland, and will largely be constructed of local materials." In the event of the scheme being adopted Mr. Bush recommended that the council should immediately authorise the prosecution of the survey, the installation of rain and stream gauges in all the valleys to be developed, and the sinking of trial holes on the sites of the proposed dairs. There vas also the matter of acquiring the lands not at present owned bv the council. In conclusion, he saad that i.otne policy for the future, must be adopted now, and it should be comprehensive enough to make progressive additions to the tupoly at the least posfible cost. Waterworks Engineer's Estimate. Also attached to the Mayor's report was one from the waterworks engineer dealing with future development. Mr. Carlaw stated that taking the past increase of population of 100 per rent, during the last 20 years as an indication of the future, it would mean that in 1941 the population would be 214,000 and the consumption 12,000.000 gallons per dav, which co,ild be obtained from: Running water, Waitakere, 1.300.000 gal.ons: running water, Nihotupu, 1,300,000 gallons; from storage 190 days without rain), 9,400,000 gallons ; total, 12,0C'.000 gailons. As the niarcin of days without rain in 20 vears from now was tco small it would be within 10 years to proved with the third portion of the adopted scheme, namely, the Huia, from

which could be obtained in running water done £000.000 gallons per day. This S' heme lent itself to unlimited stor--1 ace below the cravitation level. i As to how long the increased storage 1 would that, entirely depended 011 j the capacity of the rlani in the Huia and ! Nihotupu valleys, which without a sur- | vev would be diffi-ult to estimate, but from superficial observation i', would corI tJ-inlv be greater than the Nihotupu dam. Assuming this was correct., it would mean that '.n 1941 with a consumption of 12.000.000 gallon-, per day, the council, ,u Id depend ■■■" that quantity for 214 (iajo without l.ir-'. Referred to Committee ot Council. 0 The three reports were referred to the | committee of the whole council. The I Mi- t siid member* of the council would bo asked to visit the Huia. at a (bite to be fixed 111 November. Mr. J- A. C. Allum ;-a.id it would bo well to keep in mind tho future development of the Waikato in connection with the Lake Taupo proposal. He favoured full data lieinir obtained regarding that scheme, and. in the meantime, suggested that the varou.' local bodies in the Waikato might be a.-ked for their views on the proposal The Mayor said Mr. Allum s points could be considered by the committee of the whole council.

Of the streams named ir, Mr. bush s report, fo-ur How into the Manukau Harbour, and the others debouch on the west coast. The Nihotupu St; earn, on which the auxiliary dam was icently completed arid the main dam is low in course of construction, runs out into big Muddy Creek. To the westward, traversing Coruwallis Park, is the Kakamatua. Plowing into Huia Bay are the Huia and Karamatura Streams. Going northward, from the North Head of Mamjkau Harbour are the WTiatipu, Pararaha, and Karekare Streams. Further north again are the Piha, Wekat-ahi. and Ma.r<> whara Streams.