November 17 - 23, 2019: Issue 429

 

The Manly Dam Project exhibition: Art and science come together in new MAG&M-WRL celebration exhibition

The Manly Dam area is a picturesque landscape, rich in natural biodiversity and Aboriginal cultural significance. It is also a landscape shaped by engineering and science as a result of the construction of the dam. 

So it is very fitting the area is the subject of a special exhibition, the third in a series of major art and science partnership projects involving the Manly Art Gallery & Museum. The Manly Dam Project exhibition (6 December – 23 February) is proudly presented in conjunction with the Water Research Laboratory (WRL), a facility of the School of Civil and Environmental Engineering, UNSW Sydney and supported by the Aboriginal Heritage Office.

MAG&M’s Senior Curator, Katherine Roberts said bringing the artists and engineers together on site at the research laboratories at WRL, adjacent to the Manly Dam, created real energy and an opportunity to say something meaningful about place and water.

“The result is that the eight contemporary artists have created new works inspired by place, history, water management and engineering.  

“The artists immersed themselves in the site, initiated their own research and enquiries, learned from the WRL engineers, educators and historians and created new series of works.”

The WRL has a strong connection with the area. 2019 marks the 60th anniversary of the laboratory in the grounds of the Manly Warringah War Memorial Park, adjacent to the Manly Dam, nestled in the bushland below the dam wall. 

Katherine Roberts said many of the artists focused on the Dam itself. 

“Four of the artists (Blak Douglas, Shoufay Derz, Melissa Smith and David Middlebrook) took as their inspiration the Manly Dam environment itself, all of them deeply respectful and responsive to the Aboriginal cultural heritage of the area. They researched its biodiversity, social history and engineering story to create work that is poetic, powerful and provocative.” 

“We hope this project deepens our understanding of the Manly Dam area as a significant site for cultural understanding, environmental study and for raising the awareness of issues related to water management more broadly.” 

The joint curator for the project, Director of the WRL, Professor Ian Turner said: “Artists and researchers share a common aspiration to discover, understand, interpret and communicate the natural and cultural environment we live in.” 

“It is the very existence of Manly Dam that resulted in the decision in the mid-1950s to establish WRL at the University of New South Wales’ Northern Beaches Campus in Manly Vale.

“So with 2019 marking the 60th year that the UNSW Water Research Laboratory (WRL) has been in operation at the base of Manly Dam, it is especially fitting to participate in an arts-science partnership focused on ‘place’, with a particular emphasis on the critical role of water and coastal management to Australia’s future.” 

Artists
Shoufay Derz
Blak Douglas
Nigel Helyer
David Middlebrook
Sue Pedley
Melissa Smith
Cathe Stack
Nicole Welch

Participating Engineers
Ian Coghlan
Chris Drummond
Francois Flocard
Mitchell Harley
Alice Harrison
Tino Heimhuber
Gabriella Lumiatti​​​​​​​
Ben Modra​​​​​​​

PUBLIC PROGRAMS:                                                                                                  

Artists ‘in conversation’                
Sunday 8 December, 3 - 4pm

Katherine Roberts leads a conversation with the artists about their experiences working on the Manly Dam Project, their creative processes and artworks in the exhibition.

Sound Walk Workshop 
Mon 10 February 2020, 10am – 12.30pm

Join sculptor, sound-artist and writer, Dr Nigel Helyer, (a.k.a. Dr Sonique) for this workshop which will lead you on an audio journey which will test the power of language to find the descriptive and analytical language to describe sound in the environment.

This event is part of the Manly Dam Project at Manly Art Gallery & Museum, an exhibition by eight contemporary artists from a variety of practices who have created new work inspired by place, history, water management and engineering. The Manly Dam area is a unique landscape rich in natural biodiversity, shaped by the interventions of engineering and science. Once the source of drinking water in Sydney’s north, fresh water continues to flow from the catchment to the sea. Along with a rich Aboriginal cultural significance, the area’s European history is layered with stories of social and recreational activity.

Dr. Nigel Helyer has forged an international reputation for his large scale sound-sculpture installations, environmental public artworks, museum inter-actives and new media projects. His practice is interdisciplinary, linking Art and Science, or more accurately Poesis and Teche in a strong embrace of the environment, community and ecology - manifest as a range of complex works that form a nexus between art, society and ecology. These prompt the community to engage with their cultural histories, identity and sense of place; inviting us to examine the abstract conditions of our world and our complex relationships to it.

For bookings and further details, search ‘Sound Walk Manly’ on Eventbrite - $60.00

Water Research Laboratory Open Day 
Saturday 15 February 2020, 9am – 1pm 

The WRL Open Day is a fantastic opportunity to experience first-hand this unique, world-class research facility. Tour the massive labs, meet the experts, and see engineering and science at work. All are welcome! If you are interested in water, engineering, science or the environment, then come along!
110 King Street, Manly Vale
For further details, visit www.wrl.unsw.edu.au

Guided Walk at Manly Dam
Friday 21 February 2020, 10am – 1pm

Join Karen Smith, the Aboriginal Heritage Office’s Education Officer on a guided walk from the Dam Wall, along the escarpment and to the Curl Curl Creek waterfall and returning along the water’s edge. Bring your own picnic lunch and water. 
The Manly Dam area is a unique landscape rich in natural biodiversity, shaped by the interventions of engineering and science. Once the source of drinking water in Sydney’s north, fresh water continues to flow from the catchment to the sea.
Along with a rich Aboriginal cultural significance, the area’s European history is layered with stories of social and recreational activity.
Adjacent to this area, now known as the Manly Warringah War Memorial Park, is a hub of international research through the work of the Water Research Laboratory (WRL), a facility of the School of Civil and Environmental Engineering, UNSW Sydney.
Bookings via Eventbrite, search ‘Manly Dam Guided Walk’. Free.                                                                                           

Manly Art Gallery & Museum      
West Esplanade Reserve, Manly NSW 2095

Open Tue – Sun, 10am – 5pm (closed Mondays & Public Holidays) Free entry
Telephone: 02 9976 1421              

Manly Dam: history and Background notes


WATER FOR MANLY.

To the Editor

Sir,— What are the Manly people doing that they do not secure — now, while they may — a watershed and reservoir for their water supply? 

Soon the deep gullies, stretching away towards the head of the Curl Curl Creek — gullies formed by nature to be vast reservoirs — will be pounced upon by land auctioneers, mapped off by surveyors, and crags and boulders will be sold to a land-hungry public at so much per foot. Going north from Balgowlah along the narrow tableland which separates Middle Harbour from the valley of the Curl Curl, you come upon one of the stations which mark the trigonometric survey. A line drawn, due east from this station would cut the valley at right angles. All the valley above this line should at once be reserved for the water supply in question. 

I believe there is not a soul living upon the whole area; and very little would have to be expended on resumption, as a considerable portion of it is still Crown lands. The best of material is on the ground for dam building, and many millions of gallons could be cheaply and safely stored. Here are rare facilities for securing an enormous quantity of pure water and protecting it from pollution at little cost. It would flow to Manly by gravitation through pipes, and could be delivered at a good height. Sheet iron pipes would do. They could be made on the ground, after the manner of the great sluicing companies in California; they are cheap, light to handle, and would last for years. 

Who will move in the matter? Where is that useful citizen, the mayor? Stir up the Manly people, Mr. Mayor, that they may add to the many attractions of their village that of a copious supply of fresh pure water. - Yours, &c, CIVIS. WATER FOR MANLY. (1884, October 13). Evening News (Sydney, NSW : 1869 - 1931), p. 6. Retrieved  from http://nla.gov.au/nla.news-article107273394

WATER FOR MANLY.

To the Editor.

Sir,— Your correspondent "Civis" has done good service in directing public attention to the splendid source for a water supply for Manly which exists at the head of Curl Curl Creek ; but he is in error in thinking that the land needs to be resumed by the Government, for after the survey by Mr. Surveyor Fariola about seven years ago the whole of the Government land forming the watershed of Curl Curl Creek was, I understand, reserved from sale. It is therefore, now Crown land. For such purpose, as I have frequently pointed out, this land is admirably suited. It consists of over 2500 acres of gathering ground at an elevation capable of supplying all portions of Manly 50ft above high water mark by gravitation. With a small expenditure a large reservoir, to equalise the supply between wet and dry seasons, could be constructed, and the capacity of the valley is equal, calculated at two-thirds of the average rain-fall of 10,000,000 gallons per day throughout the year. The municipal council should apply to the Government to have the land vested in them as trustees, and then should offer a premium for the best design for supplying Manly with the water which is at the door of their borough.— Yours, &c., GEORGE PILE. WATER FOR MANLY. (1884, October 15). Evening News (Sydney, NSW : 1869 - 1931), p. 7. Retrieved from http://nla.gov.au/nla.news-article107279103

In 1886 an Act of Parliament to provide a complete water supply for Manly created the catchment reserve. 

MANLY WATER SUPPLY.

The Municipal Council of Manly, at their last meeting, on Thursday, October 20, passed the usual legal resolution, making application for a loan under the Country Towns Water Supply Act . The first action was taken at the latter end of last year, when the watershed area, at the instance of Alderman Hayes and the Mayor (Mr C R Austin) was reserved by Government for that purpose. The necessary loan having been granted by the Government, plans were prepared and submitted for approval. The water-shed of the catchment basin is 1290 acres, and is situated about three miles from Manly, on the Curl Curl Creek, and on account of its situation is quite free from all possible contamination. A concrete dam is to be thrown across this valley, which will impound 24½ acres of water with a depth at the dam of 30 feet This supply would serve the present population for 183 days at 50 gallons per diem each. The annual rainfall, after allowance for evaporation, gives 600 million gallons, and the contents of the impounding reservoir 72½ million gallons.

The water is pumped from this reservoir into a service reservoir on the top of Fairlight Hill, through a 14in delivery main. The pumps are of the Worthington type, and are compound expansive, with steam cylinders 14in diam. and 20in stroke. Each pump is capable of delivering 40,000 gallons per hour.

The boilers are multitubular and set in a new method, each boiler being suspended from iron girders placed on the side walls, it is claimed for this method of setting that greater freedom is given for the expansion of the boiler, and that it is not touched by the brickwork ; it is specially suitable for wood firing, and costs half the price of the ordinary method. The level of the service reservoir is 230ft above high water mark, and gives a pressure of 94lb on the Corso. This pressure will be sufficient to supply ordinary boilers without pumps or injectors, and can be used for hydraulic motors, lifts, or small machinery direct from the main. 

The cost of the works is estimated at under £19,000, the interest and sinking fund amount to £1140 per annum. The revenue is obtainable from a rate of 5s per room on 5600 rooms, giving £1400 per annum, and special supplies for ordinary purposes are estimated to return another £300 per annum, from motive power for the Aquarium and other small engines; the revenue can be increased according to the quantity of water available. It is estimated that by carrying out this scheme the cost of sewerage will he greatly reduced, as the water will be available for flushing, and thus save special pumping, while the value of a plenteous supply of water for road cleansing is almost inestimable. 

The scheme has been formulated by Mr Walter A Harper, Assoc. M. Inst., C.E. His plans have been submitted to the Works Department, and have received the approval of the engineer-in-Chief for Harbours and Rivers. MANLY WATER SUPPLY. (1887, October 25). The Sydney Morning Herald (NSW : 1842 - 1954), p. 9. Retrieved from http://nla.gov.au/nla.news-article13678302

In 1890, tenders were called for the construction of a dam wall. By 1892, Manly Dam Wall was constructed by the NSW Government's Department of Public Works with Manly Waterworks, and officially opened on February 4th. It was one of the only two ‘Independent Water Supply Schemes’ in the Sydney metropolitan area; the other was at Parramatta. 

Ministerial Visit to Manly.
P.O. WANTS AND WATER SUPPLY.

The Minister for Public Works (Mr. Lyne) and the Postmaster-General (Mr. Kidd), accompanied by Messrs. Barling (Under-Secretary for Works), Darley (Engineer-in-Chief for Harbors and Rivers), and Dalgarno (chief clerk General Post Office), visited Manly on Thursday, the occasion being the opening of the local waterworks. The ministerial party and a few visitors reached Manly by special steamer about half-past 12 o'clock, and were met by the Mayor of Manly (Alderman Cameron), Messrs. J. P. Cullen, E. M. Clark. O'Sullivan. Rose. and Dr. Hollis, Ms.L.A., Aldermen, Sullivan, German, Anslow, Farmer, Hayes, Scare, and Moss, and Messrs. Aus-tin, J. Millington, D. Molyneaux, H. Harper, Gundlach (engineer for the works), and Professor Benton. 

A number of vehicles were in waiting, and the party was soon travelling away from the village in a northerly direction to the dam and pumping station at Curl Curl Creek, about 2½ miles distant. There a light luncheon having been enjoyed, Mr. Lyne, after a few speeches, started the machinery. Then a visit was paid to the service reservoir on Fairlight Hill, and the Minister having turned the water on, all haste was made on the return journey, Sydney being reached shortly before 5 o'clock. During the visit the Postmaster-General inquired into some local wants connected with his department, and it is understood favorably regarded the representations made. Ministerial Visit to Manly. (1892, February 5). Evening News (Sydney, NSW : 1869 - 1931), p. 4. Retrieved from http://nla.gov.au/nla.news-article113751826

The original Manly Water Supply Scheme comprised of a dam, pumping station, rising main, service reservoir (originally on Red Hill) and reticulation. In 1892, the Manly Dam Wall was a mass concrete, gravity structure with an original maximum height of 11.3 metres, 85.3 metres long and a capacity of 68,216,000 gallons (approximately 310 megalitres). 

The Manly Water Supply.

The Curl Curl Creek Dam (the subject of our sketch) constitutes the impounding reservoir of the Manly water scheme. It is 280ft long and 42ft high (including 5ft cut into solid rock), and is built of concrete on a rock foundation. The catchment area extends from 12,000a over virgin soil never before occupied, and is calculated to supply the dam with 100,000,000gal of water, which should secure a two years' supply for Manly at its present population. 

From this reservoir the water is pumped by two separate pairs of engines lately erected by Messrs. Gibson, Battle, and Company to the service reservoir at the top of the Red Hill Heights, which is 225ft above the level of the sea, and 200ft above the average street level. This reservoir is cut into the solid rock to a depth of 25ft, and is further enlarged by a superstructure of concrete, making a total depth of 35ft. Its length is 100ft by a width of 30ft. 

The service reservoir being located on the highest point about Manly, ensures a good pressure for the town, and even the Roman Catholic College and the quarantine station situated on the surrounding hills are to be served in this scheme. The plans for the work were prepared by Messrs. Harper and Harper, and the scheme constructed by Mr. L. R. Cundlah,C.E., their representative.


THE CURL CURL DAM.

The Manly Water Supply. (1892, February 27). Evening News (Sydney, NSW : 1869 - 1931), p. 1 (EVENING NEWS SUPPLEMENT). Retrieved from http://nla.gov.au/nla.news-article113761180

The Manly Water Supply Scheme was progressively called on to supply neighbouring suburbs such as Balgowlah and Seaforth and eventually the coastal strip of Warringah Shire to as far north as Mona Vale. Manly Council operated it for ten years. In 1902, operation and ownership of the Manly Waterworks site, including the dam wall, transferred to the Metropolitan Board of Water Supply and Sewerage at its original cost (£37,820), less the amount (£454) that had been paid off by the council. 

CURL CURL DAIRY.

This is the property of Mr. Alexander Ralston, a worthy Scotsman, and is situated on a creek of the same name, about 2½ miles from Manly on a sweeping bend of the road to Narrabeen. The farm comprises 17 acres, 10 of which are under maize, sorghum and oats. It is a well sheltered spot, and is comparatively immune from the fierce, westerly gales. 

As a dairy it is unique in the experience of your correspondent, as its cows, of which there are 60, are hand-fed, are milked regularly all the year round, and are regaled, head to head, from two rows of bails. The cows are simply in splendid condition, and compare favourably with those which are nourished only on the native grasses. They are milked twice a day, and twice a day the sweet, fresh milk from them is carted into Manly and duly delivered to customers. A shed 80ft. by 24ft. and 12ft. high, is used for storing the fodder. 

There is an engine for chaff-cutting and other matters, and the water required, for gen-eral purposes, is pumped up by a windmill from Curl Curl Creek through a quar-ter of a mile of piping. The home at the dairy is spacious and lofty, and, as befits a dairy, is kept scrupulously clean. A genuine scotch hospitality is dispensed here. Adjoining the Curl Curl dairy is what is known as Fernholme egg farm, a model of enterprise conducted by Mr. T. A. Hutchinson, of which more anon. CURL CURL DAIRY. (1906, May 18). Albury Banner and Wodonga Express (NSW : 1881 - 1938), p. 15. Retrieved from http://nla.gov.au/nla.news-article100677849

In 1906, it was necessary to supplement the local supply by connecting it with the metropolitan system (supplied by the Upper Nepean Scheme). This was done by installation of a main from Condamine Street connected to a reservoir in Brady Street, Mosman under Middle Harbour, at the Spit. 

Department of Public Works, Sydney, 22nd August, 1907
"WATER AND DRAINAGE ACT, 1902," AND "WATER AND DRAINAGE AND ARTESIAN WELLS (AMENDING) ACT, 1906."
"CURL CURL LAGOON DRAINAGE TRUST."

Notification of proposal for the construction of works of Drainage, and the constitution of a Trust for maintaining, administering, and extending such works.

WHEREAS Section 6 of the " Water and Drainage Act, 1902," provides amongst other things that in respect of any works of drainage the Minister (that is, the Secretary for Public Works) shall notify in the manner therein enacted proposals for the construction of such works, and the constitution of a Trust for maintaining, administering, and extending such works : Now, therefore, I, The Honorable Charles Alfred Lee, the Secretary for Public Works for the time being in and for the State of New South Wales, in pursuance of the powers conferred upon"me by the hereinbefore in part recited section of the last-mentioned Act and by the 4< Water and Drainage and Artesian Wells (Amending) Act, 1906, and of all other powers me hereunto enabling, do hereby notify that it is proposed to construct the works of drainage referred to in the proposal hereto, and to constitute a Trust to l»e called and known as the "Curl Curl Lagoon Drainage I rust, for maintaining, administering* and extending such works, in accordance with the particulars set forth and described in the proposal hereto, that is to say :—

The proposal hereinbefore referred to is as follows :—

(a) Resumption of the purposes for which  popowdto constitute the Trust:—To prevent the water resulting from heavy rains accumulating and to discharge same into the ocean.

(b) Plan and description of the works and of the land, whether covend with water or not, to be taken or acquired for the purposes of such works and their cost or estimated cost .—




(II.) Description of the works :—Opening a channel through the sand bar at the mouth of the Lagoon.

The works above described are subject to such deviations and modifications of route as may hereafter be deemed necessary.

(III.) Estimated Cost of the Work ... ... ... ... ... ... ... ... ... £20

(c) Rate of interest, which shall be paid by the Trust:—£4 per centum per annum.

(d) Charges to be paid by the Trust fur water to be supplied by the Crown, and the conditions of such Supply :—No water is to be supplied by the Crown.

(e) Maximum rate which may be assessed by the Trust :—One shilling per acre per annum. (f) Description of the Trust District :—

All that area or tract of country comprising part of the parish of Manly Cove, county of Cumberland, State of New South Wales: Commencing at the intersection of a north-western side of Balgowlah Road with the northern side of Harris-street, "Addiscombe Park Estate " subdivision ; and bounded thence, bearing generally westerly, by the northern side of the said Harris-street, a line, part of the western side of George-street, southerly, part of a northern side of Balgowlah Road, to the eastern side of Roseberry-street, part of that side of that street to the south-western corner of allotment 23, section D, of the " Manly Vale Estate," a line and the southern boundaries of allotment-? 19 and 10, section E, to the Sydney and Pittwater Road ; thence northerly, by part of the eastern side of the last-named road, to Kenneth Road, by part of the southern side of that road easterly to the north-western corner of block 26, a line northerly and the eastern and northern boundaries of block 20, the eastern boundaries of blocks 17 and 15, and the northern boundary of the last block to Stuart Road, part of the eastern side of that r ad to the north-western corner of block 12, a line to the southeastern corner of block 3, part of a northern side of Osbom Road westerly, the eastern boundary of block 1, a line across Curl Curl Creek to the intersection of a south-eastern side of Sydney Road with the prolongation south-easterly of a north-eastern side of Old Pittwater Road, a line and part of that side of that road to its intersection with the prolongation easterly of a southern side of a road separating blocks 86 and 87, a line at right angles to a north-eastern side of Old Pittwater Road, already described, north-easterly to Pittwater Road, by south-western sides of that road generally south-easterly to the western boundary of block 40, a line northerly, part of the western boundary of block 40, the north and north-eastern boundaries of that block, and a prolongation to the eastern side of Old Pittwater Road, a line due east 5 chains, a line due south to Dalley Road, a line south-westerly to the north-western corner of allotment 10, section 5, of the " Queenscliff Estate,'' the northwestern and southern boundaries of that allotment, the southern boundaries of allotments 11, 12, and 13, a line to the north-western corner of allotment 43, section 1, the north-eastern boundaries of allotments 43, 42,41, 40, 39, 33, 37, and 36, and the south-eastern boundary of the last-mentioned allotment to a north-eastern side of Pittwater Road, by an eastern side of that road to high-water mark in Curl Curl Lagoon, by h.w.m. in that lagoon easterly to a point on the ocean, 9J chains at right-angles easterly from the footbridge, a line south-easterly to low-water mark on the ocean ; thence by line southerly 9 chains; thence by a line westerly to the Good Samaritan Industrial School and land property, by part of the northern boundary of that property to its intersection with the prolongation northerly of the south-eastern boundary of Miss Spalding's land ; by that prolongation and thence; south-eastern boundary of the said Miss Spalding's land to a northern si'le of Pittwater Road, part of that road westerly to the south-east corner of Mrs. Baylis' land, a line and the western boundary of allotment 21, section (I, of a subdivision, a line and the western boundary of allotment 5, section 2, Rolfe's Estate, a line, the western boundary of allotment 4, section 1, a line, the western boundary of allotment 20, section 1," Farrell's Paddock," the northern and western boundaries of allotment '22, a line to the south-eastern corner of allotment 61, section 9, " Addiscombe Park " Estate, and a northern and south-western side of the aforesaid Balgowlah Road, generally south-westerly to the point of commencement—as shown on the accompanying plan, having an area of 437 acres, or thereabouts.

(g) Number of Trustees, being either three or five :—Five.

(h) Number of years within which the cost of the work shall be extinguished by a sinking fund :—One.

Given under my hand, at Sydney, this 22nd day of August, in the year one thousand nine hundred and seven.

J. A. HOGUE,

For Secretary for Public Works.

Sim:. Section 8 of the Act enables that if, within eight weeks after the notification of any proposal, a petition is presented to t'ic Minister signed by at least one-thir d in number of the occupiers of Crown land, including homestead selectors, conditional levees, and settlement leesees, and owners of other land within the proposed Trust District, objecting to the proposal, he shall refer the proposal to the Board for inquiry and report."

Section 9 reads—

(1) If within the said pewriod no such petition is received, or if the Board reports in favour of the proposal, with or without modifications, the Governor may constitute the Trust with sueh modifications of the proposal as the Board may recommend, or, where no reference is ma<lu to the Board, with such modifications as the Minister may think fit. 

(2) The constitution of the Trust shall be notified by the Minister in the Gazette.

(3) Upon such notification the conditions of the proposal, with such modifications (if any) as aforesaid, shall be binding on the Trust and on the Crown ; and the Minister may, out of the funds raised under this Act, carry out the works described in the proposal. "WATER AND DRAINAGE ACT, 1902," AND "WATER AND DRAINAGE AND ARTESIAN WELLS (AMENDING) ACT, 1906." (1907, August 28). Government Gazette of the State of New South Wales (Sydney, NSW : 1901 - 2001), p. 4894. Retrieved from http://nla.gov.au/nla.news-article226594977

The Board raised the Manly Dam Wall three times: 1909, 1914 and 1922. 

CURL CURL RESERVOIR EMPTY.

Manly, in consequence of the depletion of the supply of water in the reservoir at the head of the Curl Curl Creek, has now to depend upon a pipe which the Water and Sewerage Board has run under Middle Harbor. The consump-tion at Manly is about 6,000,000 gallons a week, so that quantity has to be added to the output from the board's main reservoir.

The reservoir at Curl Curl has been in existence for 25 years, and it has never been empty since that time until the present long dry season. CURL CURL RESERVOIR EMPTY. (1914, February 24). Evening News (Sydney, NSW : 1869 - 1931), p. 4. Retrieved from http://nla.gov.au/nla.news-article114495846

MORE WATER FOR MANLY. 


The work of raising the wall of the dam at Curl Curl Creek 20ft 3in higher has now been completed, and the residents of Manly will no longer have cause to complain of a shortage of water. The enlarged dam has a capacity of 428,000,000 gallons, an increase of 335,000,000 on the capacity of the old dam. The height of the wall is 57ft Sin, and its length 680ft. The lake area is 90 acres. (Photo: A. Foster.) Some Yachting Reminiscences. (1922, January 25). Sydney Mail (NSW : 1912 - 1938), p. 8. Retrieved from  http://nla.gov.au/nla.news-article169771886 

By 1928, increasing demand for water had overtaken the dam's capacity and in 1929 it was phased out, with supply for Warringah and Manly being provided by pipeline from the main metropolitan system at Pymble Reservoir. 

In 1930, the Manly Warringah Water Scheme was officially opened, to cater for the growing population. Water from the artificial freshwater dam created by Manly Dam Wall was used only to supplement supply to a small local area nearby until 1933. In 1936, the use of the artificial freshwater dam as a potable water supply ceased, and the pumping plant was subsequently dismantled. 

In 1939, the Reserve was dedicated as the Manly Warringah War Memorial Park. 

When the general water storage position became critical during the 1934-42 drought, Manly Dam was re-commissioned as a temporary potable water supply. This involved the transfer of the lower set of pumps from Engadine that were no longer required for the Sutherland water supply. After 10 months of use at the Manly Dam site, these pumps were removed to Pipe Head in October 1942. 

MANLY DAM TO BE USED

Work to enable water to be drawn from the Manly dam as required has been completed. The president of the Water Board, Mr. T. H. Upton, in announcing this, said that the water stored in the dam had been held in reserve for emergencies. MANLY DAM TO BE USED (1941, December 26). The Sydney Morning Herald (NSW : 1842 - 1954), p. 3. Retrieved from http://nla.gov.au/nla.news-article17780463

During World War II, the dam was fortified with machine guns and barbed wire. After WWII, the public reserve was used for recreational purposes. The Board ‘retained ownership of the dam and its land downstream of it where it has built an hydraulic model-testing station, and has carried out extensive investigations in connection with the design of its major works’ (Aird 1961: 82).

The dam wall was strengthened in 1979-81 using ‘post-tensioning’ to bring the dam up to current safety standards. This technique was considered revolutionary at the time and gained world recognition when a paper was presented by Sydney Water Board engineers to the 14th Congress of the International Commission on Large Dams in Rio de Janeiro in 1982. [1.]

The flora of the park is dominated by Hawkesbury sandstone vegetation, with six distinct native vegetation communities, including the endangered Duffy's Forest Ecological Community. It also includes some areas of highly disturbed vegetation. For an urban bushland reserve, Manly Dam Reserve is considered a floristically rich area, with more than 300 native plant species recorded, including 18 different species of native orchids.

The diverse range of plant communities in the Manly Dam Reserve provide a home to a wide variety of native wildlife.

The parks mammal population includes the commonly seen brushtailed possums, ringtail possums, swamp wallabies, brown antechinus, bush rats, long-nosed bandicoots and short-beaked echidnas. More secretive and less commonly seen species include a range of microbats including the threatened eastern bent-wing bat; the threatened eastern pygmy possum and grey-headed fruit bat. There were also records of koalas and spotted-tailed quolls being seen within the reserve, but none lately.

More than 80 species of birds have been recorded from the Park, including a variety of waterbirds and migratory species. The Park also provides an important refuge for many species such as wrens and thornbills which are becoming increasingly rare in urban bushland areas. Large predatory birds such as Powerful Owls are also regularly sighted in the reserve.

Reptiles are commonly encountered by visitors to the park with Eastern Water Dragons, Water Skinks and Lace Monitors and a variety of smaller skinks and geckos often seen near picnic areas and along walking tracks. The much rarer Rosenbergs or Heath Monitor can sometimes be seen by keen observers in more remote areas of the Park. Although Red-bellied Black Snakes and Common Brown Snakes are also often sighted along tracks, the park is home to a range of less often seen snakes such as Yellow-faced Whip snakes, Marsh Snakes, Golden-crowned Snakes, Diamond Pythons, Blind Snakes and Tiger Snakes. Eastern Long-necked Turtles also occur at the dam but are rarely seen by visitors.

Several species of frogs occur in the park including the Common Eastern Froglet, Eastern Dwarf Tree Frog, Striped Marsh Frogs, and Perons Tree Frogs. Manly Dam Reserve is also home to the threatened Red-crowned Toadlet which is associated with the rocky ridges and drainages of the Hawkesbury Sandstone formation.

There are a variety of native and introduced fish in the waters of the reserve. Native fish include species such as Climbing galaxias, Fire-tail Gudgeon, and Short-finned and Long-finned Eels. The Climbing galaxias inhabits some of the less disturbed creeks and is able to climb up wet rock faces and cliffs with the aid of ridges on its fins, can breathe through its skin, and has lived in this once remote area, for an estimated 60 million years. 

Australian Bass once occurred naturally in Curl Curl Creek but were unable to recolonise upstream areas once the dam wall was built in 1892 and blocked their access. Young Bass fingerlings are now regularly stocked into the dam by the NSW Department of Primary Industries to cater for recreational fishermen. A lone stocking of Silver Perch occurred in the early 1990s but these have not been stocked since as they are not native to the catchment area. Some of the introduced species include European Carp, Goldfish and the pest fish Gambusia. Unfortunately the dam is now also home to a large population of Redfin which were illegally introduced and now prey on many of the smaller fishes.

Manly Dam Reserve provides an ideal location for school, university and community groups to study the ecosystems present.

In 1999 the local community mounted a vigil and blockade to try and stop the contentious "Ardel" housing development from proceeding at Allambie Heights in the upper catchment (now called Maddison Way). Over 1,000 people attended a demonstration near the site, and the "Jam for the Dam" march and music event was organised in Manly, attended by over 4,000 people. There were also rallies at NSW parliament and Warringah Council. A golf tournament Save Manly Dam Golf Classic was held at Wakehurst Golf Club. The attendees included Peter Garrett, Tony Abbott, Cliff Lyons, Craig Riddington and Guy Leech. Ultimately the battle was lost and the development proceeded.

In 2014 the integrity of the Manly Dam Reserve was again threatened when the NSW Education Department lodged a development application with the then overseeing local government body Warringah Shire Council for the redevelopment and expansion of the Manly Vale Public School. The development would significantly increase the size of the school and would result in 4.37 hectares of significant native bushland being cleared from the Manly Dam Reserve for Fire Asset Protection Zones.

Concerned residents and members of the wider community, including members of the Save Manly Dam Bushland community group, objected to the proposal on several grounds; a significant fire and evacuation risk for the proposed increase in student numbers; parking and traffic issues in small residential streets; and the loss of significant areas of native bushland belonging to the Manly Dam Reserve and adjacent Council Land – home to a variety of protected and threatened native fauna and flora. Several Threatened Species including the Eastern Pygmy Possum, Red-crowned Toadlet, Powerful Owl, Eastern bent-wing bat and the Grey-headed fruit bat are known to occur in the area. Although a Species Impact Statement was presented by the Education Department with the Development Application, a large number of wildlife species that are known to utilise the site were not recorded due to the limited survey period and time constraints. A group of concerned biologists from the University of Sydney echoed the concerns of the community, and advocated that the school be built up, and not out, thereby conserving the integrity of surrounding bushland, the Manly Dam Reserve and its associated fauna and flora.

On December 20th 2016 the school development was approved by the Sydney North Planning Panel. The state government installed administrator of the then forcibly amalgamated councils Dick Persson said that the decision was not the councils position and maintained that “Council is strongly opposed in its current form as was the previously elected council in Warringah.”  [3.]

The Save Manly Dam Bushland community group continue to care for the reserve with volunteers conducting a monthly session of bush regeneration and rubbish removal.

Most recently the group has been vocal about a proposal to relocate Forest High School to a former landfill site at Aquatic Reserve (Manly Warringah War Memorial Park) where uncontrolled waste was dumped in the 1970’s, before being capped by playing fields. 

In September 2019 a post on their Facebook page read;

'This action-packed sequel could feature the release of toxins into Manly Dam, kill off the unique resident climbing fish and result in yet more gory clearing of very rare bushland for fire breaks. Fascinating sub plots include the grim prospect of moving children to a contaminated site and the likely eviction of the Baseball community.

The critics have already panned this idea, so ... it’s likely to be another Christmas Eve release. Hopefully this predicted flop will be re-edited and the script radically changed. The following synopsis has been sanitised for the media:- https://tinyurl.com/yychka36

Meanwhile, Part 3 of the trilogy. “The Tunnel That Ate Manly Dam” is also on the drawing board- this promises to be yet another gruesome horror story:- https://tinyurl.com/yarxnsva[4.]

References

  1. Manly Dam - Wall -, Sydney Water webpage, retrieved from: https://www.sydneywater.com.au/SW/water-the-environment/what-we-re-doing/Heritage-search/heritage-detail/index.htm?heritageid=4573702&FromPage=searchresults
  2. TROVE - National Library of Australia
  3. Manly Dam - Wikipedia
  4. The Save Manly Dam Bushland community group Facebook page
Manly - Manly Dam raising, 1921-2, from Album: Water Board (showing sewage works, dams, reservoirs and pumping stations at various locations), ca. 1921-1935 / photographed by Arthur Ernest Foster, Items No.: a6945049h, a6945050h, and a6945051h, courtesy Mitchell Library, State Library of New South Wales