Monday 1 March 2021

The building of Sullivan's Dam

The continuing growth of the City of Dunedin in the late 19th century meant an ever-increasing need for water.  The supply from the Ross Creek reservoir of the 1860s was suplemented by that of the Silverstream water race of the 1870s.  But it was not enough.  The Water of Leith was considered, but the effects of farming and industry on its banks meant that any supply from there would need to be from a side stream or further up the valley, where the flow came from uncut forest.  Another possibility was the water from the slopes of Swampy Summit, flowing into the Waitati Valley.

Also discussed was a means of water storage.  This was another ongoing problem, complicated by the complex nature of the local geology and possibility of earthquakes.  Dunedin residents may remember the movement in 1979 of a large piece of the suburb of Abbotsford - which slid on a liquified portion of what is known as Abbotsford mudstone.  Evidence of this geological layer can be found at differing altitudes in many places (I have done so) and the idea of placing a dam and a large weight of water in Leith Valley was one which needed much thought, as the result of such a dam's failure and the sweep of water down the valley to North Dunedin was foremost in many minds.

By the end of the 19th century, the scheme was decided - water would be taken from a branch of the upper Leith and three streams which run into the Waitati Valley would be piped under the saddle which is now known as the Northern Motorway summit.  It would be held in a reservoir on the Upper Leith at a height which enabled gravity supply to the upper suburbs - at that time separate boroughs - of Dunedin.


DUNEDIN AND SUBURBS WATER SUPPLY.

THE WAITATI-LEITH EXTENSION. 

About two years ago the City Council resolved to supplement the water supply of the city from the Waitati and Leith  Streams, with a view to providing not only an additional supply for the city, but also a supply for the suburbs. The special object aimed at was, in the first place, to increase the city supply proper, and at the same time to draw off from such a height that the high suburbs could also be supplied. This scheme proposes to utilise the water from close on 2000 acres of the Waitati branches and about 1700 acres of the Leith gathering grounds, which together are about three and a-half times the extent of the Ross Creek watershed. From those figures our readers will be able to form some estimate of the adequacy of the addition. 

The water from the Waitati branches being brought alongside the hillside in stoneware pipes, and thereafter in an iron pipe across Williams Creek gully to the saddle between the Leith and Waitati, where it will be discharged into the Leith channel and stored in a reservoir within a mile of the saddle. The principal Leith tributaries which will be utilised will be the West Leith and Morrison's Creek and part of the main Leith. The whole of these creeks come off virtually virgin ground, partly forest and partly open, but all of a character to give water of excellent purity.

The water for the high suburbs, if the municipalities decide to take a supply from Dunedin, will be conveyed in a pipeline to Bellevue trig station, which is the highest point of Roslyn along the main ridge, and is 700 ft above the sea, and from that it can be distributed to the other parts of Roslyn, and also of Mornington. There will be a service reservoir specially for the use of the highest parts of Dunedin, in which the pressure at present is inadequate. It will be situate at what is called Driver's Corner, at Maori Hill, and the pipes will be brought down through the Town Belt, and the connection made witlh the present service somewhere in Royal terrace.

In connection with the general scheme, as above sketched, a commencement was made in August by the collection of the waters of the Leith and Morrison's Creek at their junction and since then the pipes for the conveyance of the water have been laid along to Ross's Creek, and since the beginning of the year that water has partly supplied Dunedin, enough being taken only to meet the daily wants. The pipes have also been carried on from Ross's Creek through what is known as the slaughterhouse paddock, crossing the deep gully of the Schoolhouse Creek on to the Balmacewan road, and along that road to near the service reservoir at Maori Hill.

With regard to the service reservoir, detailed surveys have been made, and trial shafts sunk with the view of ascertaining the material that will have to be dealt with in excavating. The present intake is at a sufficient height to carry the water on as far as the Council Chambers, Roslyn, or to put it in a more practical way, at such a height as will give a supply with enough pressure as far on as St John's, Roslyn. The work for the collection of the Waitati branches have commenced, but so far only the track is being cleared and a rough road made for the conveyance of pipes. The work that has been carried out so far under the supervision of Mr G. M. Barr, C.E. now completely ensures the city against drought. In the accompanying reproduction our photographer has succeeded in obtaining a capital view of the route of the fluming in a picturesque part of the Upper Leith Valley.  -Otago Witness, 17/2/1904.


Additional bores and shafts sunk on the site of the proposed embankment at the Upper Leith water supply reservoir give indications of a better foundation than was at first supposed to exist there. A good deposit of clay has been discovered close at hand, and this will be valuable when putting in the puddle wall. A start will be made with the excavations as soon as the necessary plant is available.   -Otago Daily Times, 15/7/1905.


WAITATI-LEITH WATERWORKS.

A VISIT OF INSPECTION.  (excerpt)

The journey was continued over the Helensburn saddle, which the main pipe has been tunnelled through, and then up the Leith Valley, where a halt was made at Morrison’s Creek and its water thoroughly tested, and then further up the Valley the site of the proposed large reservoir was viewed with approval; and again onwards to the Waitati-Leith saddle, from which, a magnificent view is obtained of the east coast of Otago, which alone would be ample recompense for the trouble of the journey, but as it was not the aesthetic that the party were especially bent upon, the waggonette was left at the crossing of Williams Creek and the party started to walk, a mode of locomotion which gave excellent opportunity to examine both natural and artificial objects of interest. Attention was given at once to the tank constructed of solid masonry which is designed to collect the waters of that creek and those coming from Burn’s and Ferguson’s Creeks further north, and to supply them to the 20in cast-iron pipe which conveys them across the saddle into the Leith Valley for storage in the large reservoir already mentioned. Much satisfaction was felt at the quantity and quality of the water of William’s Creek, which comes direct from the mountains and possesses all the qualities which water for human consumption should. The walk was continued along a track formed through the bush at a grade suitable for conveying the water in stoneware pipes, which at this part are 18in in diameter; but it was explained that in higher stages the sizes will be 15in and 12in, with a length of 13 chains of malleable iron pipe to be laid on a slope formed by a natural fault in the country with a throw of 190ft. The track was unusually dry, and therefore all the more pleasant for the pedestrians, who on this occasion were charmed with the opportunities for seeing ferns and tree foliage to perfection under circumstances of bodily comfort. The climb upwards on the slip was not accomplished without perspiration, and then a pleasant tramp through flaxes and tussocks brought the party to the first and highest intake — that of Ferguson’s Creek, which again showed water of crystal quality, though, owing to the smaller gathering ground above it, of considerably less quantity than the main creeks lower down. This point is 1,426 ft above the sea level, is 9 miles and 6 chains from Royal terrace, and the water will traverse stoneware and iron pipes to the Waitati saddle, 1,189 ft above the ocean, thence to a large reservoir to hold 100 million gallons, 1,000ft above the sea, and then inwards in cast-iron pipes over a country of ridge and gully to Maori Hill and Dunedin; while, if the people of the high suburbs should wish it, the water can be given to them at the height of the new Presbyterian Church at Roslyn with a head of 150 ft. 

The completion of these works as projected with those already supplying the town should make Dunedin and its variously-placed suburbs about the best served for water supply in the colony. On returning to town, well pleased with their day’s outing, the party expressed the opinion that Dunedin in this most important matter of water supply had a secured future. On Saturday morning the same party continued the inspection of the water supply from the Silverstream. By reason of recent work in cleaning out the race, the water was not so clear as the supply from the Waitati-Leith, but otherwise the race was in good order, carrying the usual supply.  -Evening Star, 17/1/1906.

The above account is one which is of special interest to myself.  Before the internet, before the invaluable resource which is "Papers Past," I walked the line of pipes described above.  That is, I walked as far as "the slip" and wondered why the old line of earthenware pipes (dramatically showing the effects of the slow by inexorable slipping of the hillside) ended at a watercourse with barely a trickle in it, after bypassing several little creeks carrying significantly more water.  It was a 20-year mystery for me, and one which led to much exploring in the area.  I did not find the pipeline leading on to Ferguson's Creek for the very good reason that it is not there.  Beyond the currently-used furthest intake on the scheme can be found a line of pipe which has never carried water.  The reason for that is, as they say, another story - and will be part of one for me in the future.


CITY COUNCIL (excerpt)

WATER COMMITTEE'S REPORT.

Cr Sullivan moved the adoption of the Water Committee's report. He regretted that the Government had seen fit to decline the council's application for an Order-in-Council authorising the construction of the proposed reservoir in the Upper Leith Valley. He regretted this, not so much for the sake of the city as for the sake of Maori Hill, Roslyn, Mornington, and West Harbour, which would have to get a supply from this high level, and more especially when the city engineer had taken out sections of the Leith, which showed that the bed of the Leith could carry all the water that would come into it in the remote possibility of the reservoir ever breaking away. He felt sure that in a few years these neighbouring boroughs would require more than the running flow of the water, and it would be impossible for the city to supply them unless it had storage in that particular area.

Cr McMillan seconded the motion, which was carried.  -Otago Daily Times, 18/5/1911.


The new reservoir proposed to be built at the Upper Leith is to be known as the Sullivan Service Dam.  - Evening Star, 30/3/1912.


Cr Wilson asked the chairman of the City Council's Water Committee last night if the building of the new reservoir at Upper Leith, to be known as the "Sullivan Service Dam," could not be proceeded with at once, in order to take in the surplus labor. Cr Sullivan, in reply, said that they were still waiting for the Order-in-Council, but steps had been taken to put it through quickly, and when success was achieved they would be able to absorb some of the surplus labor in outside construction. Finally, acknowledging the compliment paid him in the name of the reservoir, Cr Sullivan expressed a pious hope that the order of the words would never be reversed in people's minds. -Evening Star, 4/4/1912.


CITY COUNCIL REPORTS (excerpt)

The Water Committee report having instructed the city engineer to make necessary arrangements for utilising the Waipori power for driving the quarry plant and lighting the works at the Sullivan service reservoir. The cost of erecting and (when the works are completed) dismantling the plant necessary to carry the power to the site and use it there is estimated at £467. It is probable, however, that the water department may subsequently receive a considerable reduction on the first cost if customers for lighting and power are obtained on the route.  -Evening Star, 7/7/1913.


SULLIVAN SERVICE DAM.

VISIT OF INSPECTION. 

On Saturday afternoon a Times reporter accompanied Cr Sullivan (chairman of the Water Committee of the City Council) and Mr W. D. R. McCurdie (city engineer) on a visit to the Sullivan service dam, situated up the Leith Valley near the saddle leading over into Waitati. Cr Lillie, of the Maori Hill Borough Council, was also with the party. 

A stop was first made at the men's encampment, just below where the dam is being constructed. Here there are 18 tents, the tents being attached to frames and having iron fireplaces. They look very serviceable, and the men's wants are further attended to by a big cook-house being built close handy. The council provides the accommodation and the men pay 12s to the cook for board. When the work is in full swing it is expected that some 60 men will be employed. The dam is situated right alongside the Leith-Waitati road, and when it is completed and full the level of the water will be 1019 feet above city datum — that is, 972 feet above sea level. The following further figures should prove interesting. Capacity, 21,000,000 gallons; area covered by water, 11 1/2 acres at full dam; area to be grubbed and cleared on and about dam site, 17 acres; height of embankment to overflow, 25 feet; width of embankment — At overflow 44 feet, at crest 20 feet, at bottom 172 feet. Length of embankment, 230 feet; material in embankment, 11,690 cubic yards. 

It is interesting to note that Ross Creek has an area of 11 1/4 acres and a capacity of 50,000,000 gallons, and the Southern reservoir an area of 6 1/4 acres, and a capacity of 22,780,000 gallons. 

The Sullivan dam is located at a distance of six miles from the Town Hall. When it is finished the water conserved will be used to augment the supply of the high levels of the city — Roslyn Ward, Valley Ward, part of Caversham Ward, and the boroughs of Mornington, Maori Hill, and West Harbour.

The dam is situated in a broad gully, narrowing at the bottom, and the preliminary work is at present being gone on with. The engineer has been fortunate enough to discover an outcrop of stone on a hill above the dam site, and the metal will be brought down on an aerial tramway, 2000 feet long and rising 400 feet to the quarry. The crushing plant is to be worked by electricity from the city service, and the poles are now being laid on the road. Electric light will then also be supplied to the tents in the camp. 

A notable feature about the present dam which distinguishes it from other former proposals is that there will be no valve tower. The supply will be controlled from the embankment. There will be no pipe or tunnel through the embankment or through the ground near the embankment. The supply will be drawn from the dam by means of an elevating water jet, acting under pressure. The washings of the road will be all taken care of in a special conduit and carried away dear of the dam. The stormwater will be under complete control, and will be run past the dam in a concrete channel six feet wide by four feet deep, thus taking only clean water into the dam. After looking over the site of the dam the party returned and had a look at the Ross Creek reservoir, the sheet of water, surrounded as it is by beautiful native shrubs, looking very beautiful in the sunlight. 

Mr McCurdie is the engineer for the dam, and has made his arrangements with foresight, while all the details have been painstakingly worked out. One thing, which cannot but strike one on a visit of this description, is the very little knowledge the people of Dunedin have of the ramifications of the water supply system of Dunedin. Presumably the work of the Water Committee goes on so smoothly that it escapes attention. Connected with the water supply is the purchase of large tracts of catchment areas, and cattle are at once fenced off from these properties, which are then brought under the sway of Mr Tannock, who has planted thousands and thousands of plants of all varieties on the reserves. The water supply department is the one which returns the greatest profit of any of the trading concerns, and that the system is proving so successful from a utilitarian point of view as well as financially, is largely due to the chairman of the committee (Cr Sullivan). This gentleman had devoted much time and thought to the water department, and one has only to be in his company for a few minutes to realise fully the wonderful grip he has of his subject. Tramping over hill and dale in his spare time personally inspecting the service, working out figures, and taking an all-round intelligent interest in the system, Cr Sullivan has proved, and is proving, an ideal chairman of the committee. He well deserved the compliment conferred on him by the council deciding to call the reservoir the Sullivan service dam.  -Otago Daily Times, 4/8/1913.

A 2021 visit to the quarry and a few minutes' searching found this relic from 110 years ago.

The quarry face, visible from Dunedin's Northern Motorway - if you aren't driving and know what to look for.


The view of the reservoir from the top of the quarry. Between the pine branches can be seen part of the diversion channel.


The 30 men at present employed on the construction works at the Sullivan service dam were paid off yesterday, in consequence of the conditions imposed by the Arbitration Court in the recent new award made governing general labourers. This award provides that an extra 1s 9d per day shall be paid to labourers employed on "country work," and the men working on the Sullivan dam apparently come under this definition. As the extra money required to be paid will involve the corporation in an altogether unexpected additional expense, the city engineer (Mr W. D. R. McCurdy) resolved to dispense, with the services of the men until the position can be brought before the City Council. Up till the time of the new award the labourers at the dam were in receipt of 9s per day, with free lodgings, light, fuel, and other conveniences. Under the new award, however, the payment was increased to 9s 4d per day, with the stipulation that "labourers employed upon country work shall be paid an additional sum of 1s 9d per day for six days in the week, but the employer may, in lieu thereof, provide them at his own expense with suitable board and lodging.'' An anomaly presents itself in the case under notice, in so far as the quarry workers employed at the dam are concerned, as they are working under an agreement in which they will not receive the 1s 9d per day extra.  -Otago Daily Times, 25/12/1913.


We understand that a deputation from the Otago General Labourers' Union is to wait on the City Council at its meeting on Wednesday to complain of the attitude taken up by the council in regard to the employment of men at the Sullivan service dam. The new award recently drawn up by the Arbitration Court stipulated that "country workers" — that is, men who have to "sleep away from home" — were to be paid 1s 9d per day extra, or be provided with suitable board and lodging. The Sullivan service dam comes under the category of "country work," and it is now asserted that the council — in order to save the "extras" referred to above — is employing only single men, who are prepared to make their homes at the works.   -Otago Daily Times, 15/1/1914.


Sullivan's Dam under construction.  The square building, right of centre, would be the crushing plant.  Cables for the "aerial tramway" can be seen reaching it from the right and the bridge structure to its left would carry rails, similar to the tramway leading off to the bottom left, for tipping rock and clay fill to make the bulk of the dam.  Otago Daily Times photo. 


TREE PLANTING

DUNEDIN’S GREAT ASSET. 

A WORK OF MAGNITUDE. 

Though the Dunedin municipal trading departments are owned by the people, and run on their behalf, it cannot be said that the majority of them are particularly well acquainted with the working of at least one of their possessions — to wit, the tree-planting department. Wihin the past few years the water department of the City Corporation, in a laudable attempt to ensure as pure a supply of water as possible, has secured lands abutting on the streams running into the various dams, and prohibited the grazing of stock on them, thus preventing defilement from this source. The large area of land thus secured, however, is not being allowed to lie idle. It is, in fact, being put to a most valuable use. Some eight years ago tree-planting operations were commenced on these catchment areas. The work has been steadily extended, till to-day the operations have increased in a really wonderful manner. 

The planting has three distinct results. Firstly, the trees help to conserve the moisture and enable it gently to trickle into the feeding streams; secondly, they keep down the noxious weeds; and, thirdly —and this ultimate result is the one which will no doubt make a special appeal to the Dunedin ratepayer — the different species of trees have been selected with the object of providing, on their reaching maturity, supplies of timber suitable for all kinds of building. 

On all the hills round about the Sullivan service dam now being constructed in the Leith Valley, at an elevation of 1000 ft above sea-level, patches of trees, of various stages of growth, are to be seen, and it is quite crowned with a full mead of success. One large plot, situated near the western branch of the Leith — the oldest planted — consists of Finns muricata (bishop pine). It has been growing for eight years, and some of the trees have reached a height of close on 30ft. The trees are planted close together, and are yearly thinned. Once they have been thinned to the recognised distance they will be allowed to mature — taking about 15 years — and will then be fully ready for the woodman’s axe. At a certain stage in the growth of the maturing trees fresh plants are put in between, and when those reach a recognised height other plants are inserted in the earth. It will be seen, therefore, that tho scientific culture of trees is continuous; as the mature trees are cut down others are coming on to take their place. 

Of course the operations have been carried out on a very extensive scale, and consequently it has been impossible to keep the bottom of the trees clean by constant attention. Despite the fact, however, that a heavy sole of grass has in a number of cases practically obscured the younger plants, they are sturdily pushing their way upwards. Shortly the grass will have to succumb. Wandering over the reserve, thousands of plants — ash, oak, Norway and Menzies spruce, and other species too numerous to mention — in varying stages of growth, are steadily increasing in girth and height. While the people of Dunedin are pursuing their every-day vocations, they have an asset of which they have not a great deal of knowledge steadily coming along to profit. Mr Tannock lays great stress on the invaluable property of break winds of stronger growing trees to the young plants, and these are provided wherever necessary. He also remarked that he was obtaining better results from Oregon pine than from any other plant except Pinus insignir.

In the nursery at the back of the Ross Creek reservoir there are many thousands of seedlings — the poplars, especially, showing a fine healthy growth — awaiting their turn to be transferred to the different areas. The sides of the hill at the back of the curator’s house have also been planted with trees, and other vacant spots loading down to the Wakari road carry their full complement. It should be mentioned that the two reserves visited do not exhaust the tree-planting areas — there are others at Whare Flat, the Southern reservoir, and several other localities surrounding the city. The outstanding impression left on the mind of the reporter is that Dunedin has an asset in its tree plants whose ultimate great value cannot be estimated in any definite degree, and that the knowledge of his subject and the ability to put it into practice possessed by Mr Tannock are of a really high order.  -Otago Witness, 24/6/1914.


PERSONAL ITEMS

Mr A. J Sullivan, who has left Dunedin to take over a sheep run in Central Otago, has sent in his resignation as a representative of Central Ward on the City Council. Mr Sullivan was recognised as one of the hardest-working members of the council, and during his lengthy term of office rendered valuable assistance to the city as chairman of the Water Committee, he having a most intimate knowledge of the ramifications of the mains running through the town, the works at the reservoirs, etc. It was as a compliment to Mr Sullivan’s services on the Water Committee that the council decided to name the new reservoir now being built at the Leith Valley the “Sullivan Service Dam.” Mr Sullivan also held for a period the chairmanship of the Works Committee.  -Otago Witness, 7/10/1914.


CITY COUNCIL REPORTS (excerpt)

The Water Committee recommends that authority be granted to expend a sum estimated at £2500 in removing certain clay spurs and other irregularities and excavating to a depth of 1ft from the bottom of the Sullivan service dam. The work is outside the present scheme, and the advantage to be gained by giving effect to the recommendation would be increased storage space to the extent of 7,000,000 gallons.  -Otago Daily Times, 29/11/1915.


The Sullivan service dam will be formally opened to day. The ceremony will be performed either by the Mayor (Mr J. J. Clark), or by the chairman of the Water Committee (Cr Wilson). A number of motor cars will leave the Octagon at 2.15 pm. for the purpose of conveying members of the City Council to Leith Valley, where the turning of the handle will take place, admitting the water for the first time. A general invitation to be present has been extended to those of the public who are interested in the function.  -Otago Daily Times, 15/7/1916.


SULLIVAN'S DAM

OFFICIAL OPENING. 

On Saturday afternoon Cr Wilson (chairman of the Water Committee of the City Council), accompanied by his Worship the Major (Mr J. .J. Clark), and the other councilors and their wives motored to the recently completed Sullivan's dam, so called after ex-Councillor A. J. Sullivan, who initiated the proposal to construct this dam and saw it well on the way to completion before he resigned from the council. The occasion of Saturday's visit was the formal ceremony of turning on the water. 

The Mayor presided over the gathering at the dam, and called on Cr Wilson to address those present. 

Cr Wilson referred at the outset to the original proposal to construct the Leith-Waitati scheme, which after being investigated, was abandoned. Mr McCurdie then investigated the present site, and plans for a smaller reservoir were prepared. On June 2, 1909, authority was obtained to proceed with the work, the Government stipulating that the reservoir should not be more than 30ft above the town. Plans were submitted to the Public Works Department, and were 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 the dam. The dam had been called Sullivan Service Dam, after Mr A. J. Sullivan (ex-chairman of the Water Committee) was a fitting recognition of his able services to the city, particularly in connection with the Water Department. It was not until February 20, 1913, that authority to construct the dam was gazetted, and the work was not commenced until May 16 of that year. However, it had been pushed on steadily, and had been completed this month. The original estimate was £22,000, but authority 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 the dam was completed at a total cost of £27,000. The whole of the material, with the exception of the iron work, had been prepared by the corporation employees, the result being a considerable saving to the ratepayers. The dam consisted of a central core wall of puddled clay, averaging 12ft thick. This puddle core was down to solid watertight ground to a depth of 34ft below the surface. Above the ground the puddle core was carried to the top of the embankment. The embankment on each side was made up of stone and clay in the proportion of two loads of stone to one load of clay. The puddle core was rammed with hand rammers and tramped with men's feet as tight as possible. The stone and clay in the embankment were rammed with power rammers till each layer of stone came in contact with the layer beneath the clay, merely filling the corners. The main body of the embankment was therefore a sort of masonry with clay mortar, and would not subside, and would be very difficult to damage. The face next the water was pitched with rock; and near the top, where waves would give most trouble, it was faced with concrete flags. A storm channel surrounded the reservoir for the purpose of catching dirty flood water and keeping it 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 off the whole area above it. The spillway from the reservoir at the west end of the dam was capable of dealing with rather more than an inch an hour over the whole catchment above the dam, so that should anything happen to the storm channel in a flood the spillway would deal with the water and prevent any flood from getting near the top of the dam. The water surface of the reservoir was 13 1/2 acres, the depth at the embankment 20ft, and the quantity of water it held some what over 25,000,000 gallons. An immense quantity of buried timber was removed in the clearing of the bottom over the acres. 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. This material was trucked to the embankment on light railways, hauled over the embankment with electric gear, and tipped where it now lay behind the dam. The maintenance of the road to town was taken over by the City Council from the Maori Hill Borough, when the work began, to prevent disputes on the subject of the extraordinary traffic caused by the City Council's operations. This resulted in a steady improvement in the condition of the road, which was now in very good order all the way to the saddle. A storm water drain had to be laid from the saddle to a point below the dam. This drain took all the washings of the road, and prevented any pollution of the water from this source. Besides the water falling on the 375 acres of land in the catchment of the dam, water from 1300 (acres) of the heads of the creeks in the Waitati basin was brought into this reservoir. This water was caught in an earthenware pipe line about two miles long, running along the face of the hills the bush. It was brought through the saddle in a tunnel, and turned into the Leith, down which it ran into the dam. Some of this water was caught at the saddle and brought down to the embankment under pressure in a 9 inch cast iron pipe. This pressure was used to lift the water from the reservoir over the embankment. It was (usually) used to empty reservoirs by a pipe or tunnel through the embankment or by the embankment. This was always a source of weakening and danger. It was calculated that about 90 percent of the failures of earthen dams was caused by the failure of the pipe under the embankment, or through leaks developing about the pipe. This source of weakening had been avoided in the dam by jetting the water over the top of the embankment. It was believed to be the first case of the kind on record. The work had been carried out in a most creditable manner by the engineer (Mr McCurdie) and his assistant Mr King applied labour-saving appliances to a number of ways, and it was a credit to the department the way the men had been housed and catered for. There was firewood in abundance for them, and the electric light was put on to their houses and they were provided with a social hall. Cr Wilson then called on the Mayor to turn on the water, which he did amid applause.

The party then repaired to the big social hall formerly used by the men, where they were entertained at afternoon tea, which proved most enjoyable. 

Cr Wilson proposed the health of the engineer (Mr McCurdie) who, he said, was leaving on a trip to Australia on Wednesday. He said their engineer had been criticised very hardly and in many cases unnecessarily. They should judge a man by his works. Now and again there had been charges levelled against him which had been proved to be without foundation. He wished Mr McCurdie bon voyage and a safe return. 

Mr McCurdie suitably acknowledged the compliment paid him. 

The party then returned to Dunedin.  -Otago Daily Times, 17/7/1916.


There is a detail above which impresses me greatly.  The use of some of the water from the Waitati Valey, the main source of water for Sullivans Dam, taken from the pipe which goes under the summit of the pass where the current motorway now passes, taken from its higher elevation to the dam and therefore developing pressure as it descends, and being used to draw the reservoir water up and over the top of the dam.  

It is a very similar technique to the "elevation" technique developed to take gold-bearing gravel up and out of a hole by taking water down a pipe then, at the bottom of the pipe, making a U-turn and forcing the water back up to a lower height than that from which it started its downward journey.  Just above the U-turn there is suction, into which can be shovelled the gold-bearing gravel, to travel up the exit pipe and out to the sorting tables where the gold can be taken which makes (hopefully) the entire operation profitable - the bringing of water from (often) a long distance in races in order to obtain the height and therefore the pressure, the buying and transporting of the iron pipes to make the elevating equipment and likewise for the wooden structures needed to support it all.

The "elevation" technique would have been well-known to engineers of that time.  To use the principles to make a pressure-assisted "reverse syphon" is very innovative.


Sullivans Dam, 1920.  The structure to the left on the hillside looks like a support for the aerial tramway from the quarry.  Photo, DCC archives.


OBITUARY

MR A. J. SULLIVAN 

There passed away at his residence, 9 Albert street, this morning, Mr Archibald James Sullivan, who was very well known in business and sporting circles of New Zealand. 

Mr Sullivan was sixty-three years of age, and was born in Dunedin being the son of Mr M. Sullivan, who was a Mayor of South Dunedin when that part of the city was a borough. He received his education at the Christian Brothers’ School, where he matriculated. He entered the teaching profession, but left it before long to take up insurance work, obtaining employment with the Standard Insurance Company. He left that company to become agent at Cromwell for Barr, Leary, and Co. during the gold boom there about the beginning of the present century. On returning to Dunedin he was appointed Dunedin agent for the Australian Alliance Assurance Company, but just on the outbreak of war he took up a sheep run in Central Otago, a few miles from Clyde. He came back to Dunedin in 1918, and later went into business on his own account. Mr Sullivan was keenly interested in sport, and for many years was a member of the Dunedin Amateur Boating Club, and he also belonged to the Dunedin Amateur Athletic Club. He played football for the old Pacific Club, afterwards joining the Dunedin Club, and he represented Otago on the football field. Cycling was another of his activities. He joined the Dunedin Bowling Club after his return to the city, and he was president of that club during the 1930-31 season. He was a member of the directorate for some years, but retired at the last annual meeting. He was a member of the Dunedin Bowling Centre, and held a seat on the council of the Dominion of New Zealand Bowling Association, being treasurer in 1930. Mr Sullivan went to a great deal of trouble in arranging draws for the various competitions, and it was largely due to his efforts that the bowling tournaments in Dunedin in the past few years ran so smoothly. 

Civic activities also attracted Mr Sullivan, and he was a member of the City Council from April, 1907, till his retirement in September, 1914. He was chairman of the Water Committee for some time, and the Sullivan Dam, which was constructed during his chairmanship, was named after him. He was a member of the Fire Board from the time of its constitution till he resigned in October, 1914. He was also a justice of the peace. Mr Sullivan leaves a widow and two daughters to mourn his passing.   -Evening Star, 12/9/1932.


Andersons Bay Cemetery, Dunedin.  DCC photo.


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