I picked up the phone and was told that there had been an explosion at the Cinema Centre in Canberra and that a man had been killed. We were asked to investigate. The picture below shows the Old Cinema Centre in the centre of the picture and the Dendy Cinema Centre of today in the top right hand corner and a petrol station was located opposite but to the left.

CinemaCentre1

I had mapped the excaavation on which the Cinema was built shortly after my arrival in Canberra. In the north wall there was a depression in the top of weathered clayey mudstone that was filled with gravel and water was leaking from the gravel during and after rain. After the Cinema was built water ponded behind the north wall and algae grew in the sump inside the building.

The management realised that there was ponding of water and drilled a hole in the wall to allow the water to enter the sump and then pumped into the stormwater drain.

During rain the water level rose until it flowed through the hole into the sump; however. Petrol also flowed in through the hole.

The plumber was called in to install a pump to remove the water. When the plumber lit his blowtorch the pertol exploded; he was knocked unconcious and fell into the sump and drowned in three inches of water.

CinemaCentre2

 

Having identified the problem, a number of observation holes were drilled and all contained petrol. The obvious source of the petrol was from the Service Station opposite. X-ray diffraction tests showed that the petrol in the holes was similar to that at the Service Station, but had lost some of its aromatic components.

A three foot diameter hole was driklled into the gfravel in front of the Cinema; the hole was backfilled with clay and the hol.e in the wall was sealed.

The next task was to remove the petrol. A three foot diameter hole was drilled nearby and a skimmer installed in the hole. The skimmer is a cylinder of stainless steel with the bottom set in the groundwater. The cylinder is rotated and petrol that adheres to the staiknless steel is wiped off into a container. Although many gallons of petrol were removed petrol has been adsorbed by the clay soilthroughout the sujrrounding area and forty five percent of petrol adsorbed by the clay cannot be removed.

The foundations of buildings between the Cinema and Lake Burley Griffin will intercept petrol contaminated groundwater.

At the inquest in the Coroner’s Court, our report was presented. Steve, a hydrogeologist representing Mobil denied that the petrol came from the Seervice Station, but the Coroner accepted the results of our work and recommended that the remedial work be continued.

Steve and I went off to the Ainslie Pub for a beer.

 

 

E.G. Wilson,     14/7/2015

 

 

 

 

Robert Menzies was prime minister of Australia from 1949 to 1966, and was Australia’s longest-serving prime minister. Gough Whitlam led the Labour Party to power for the first time in 23 years at the 1972 election. He went on to win the 1974 election before being controversially dismissed by the Governor-General of Australia, Sir John Kerr, at the climax of the 1975 Australian constitutional crisis.

Lionel Murphy Australian politician and jurist, was Attorney-General in the government of Gough Whitlam and a Justice of the High Court of Australia from 1975 until his death. He drafted all legislation passed by the Whitlam Government which included:

  • improving the position of women and our indigenous population;
  • introducing Medibank, the precursor to Medicare;
  • needs-based funding for schools and free university education;
  • introducing the Trade Practices Act;
  • ending conscription;
  • diplomatic and trade relations with the People’s Republic of China.

Narrabundah had cheap fibrolite houses built for the workmen who initially built Canberra and the ACT administration placed single mothers and divorcees with children in them.  Roz Kelly was the Member for the ACT and she lobbied for a Health Centre to be established and it operated initially from an empty Doctor’s surgery, the baby health clinic, and one of the fibro houses. Plans for a health Centre were drawn by the National Capital Development Commission, funds were allocated and the Centre was built containing four doctor’s surgeries, a treatment room, an office for a Social Worker, a community nurses annex, and an administration centre where a Secretary-Administrator, Denise Seddon, controlled the overall operations of the Centre.

Narrabundah Health Centre - Now the Aboriginal Health Centre
Narrabundah Health Centre – Now the Aboriginal Health Centre

 

Child Care Cottage
Child Care Cottage

When the local Doctor left, my wife Melodie told me to go to the community meeting and get on the Committee to lobby for a Health Centre.  After a while members of the Committee drifted away and I became Chairman of the Narrabundah Health and Community Council.

Child Care Cottage
Child Care Cottage

The Staff told us that Child Care was required and we lobbied the Minister with the help of Roz Kelly and a Cottage was made available in Yamba Place. The Cottage was run by two retired schoolteachers and is still  serving the community today.

There was some opposition in the community to providing these services and the opposition stacked the next AGM and voted in a new Committee. A year later at the AGM, they said that there were only two children at the Cottage and closed it down. My old Committee members got together and lobbied Margaret Guilfoyle, the minister, and she turned the Cottage over to us. Within a fortnight it was running at full capacity with 22 children. Occasionally I would visit the local priest, Father Collins, and we would swap notes over a Scotch. We agreed that fundamentalists who ignore the needs of the community were a blot on society, and he commiserated with me.  He said “I won’t have a bar of them in my Church, and they try to undercut my authority all the time, but without success”.

The Health Centre is now the Aboriginal Health Centre and is providing a much needed service to the people of Narrabundah.

Denise Seddon and Peter Wilson, 2013
Denise Seddon and Peter Wilson, 2013 

E.G.Wilson,  12/07/2015

My first job in Canberra with the Bureau of Mineral Resources was logging drill core during the investigations for a dam that would turn the Canberra floodplain into a lake as envisaged by Walter Burley Griffin. The Canberra floodplain was about half a kilometre wide and the low level bridges were frequently flooded.

Molonglo River in flood , 1956.
Molonglo River in flood , 1956.
Burley Griffin original Design
Burley Griffin original Design

In 1911, a competition for the design of Canberra was launched by King O’Malley, Minister for Home Affairs, and Scrivener’s detailed survey of the area was supplied to the competing architects. Walter Burley Griffin won the Design Competition. Burley Griffin’s wife, Marion Mahony Griffin, also an architect, collaborated with him on the design competition entry, and is known to have prepared the design drawings that accompanied the Burley Griffin entry.

I attained a Science Degree in Geology with Honours at Queensland University in 1957 working on sediments to the southwest of Brisbane. I transferred to the Bureau of Mineral Resources in Canberra in May 1958 and felt the cold. I worked from an old military prefab hut that was also cold. I wore a greatcoat for 7 years, inside the office as well as outside until one day I felt hot and never wore it again. I was map editor for the maps of northern Australia, sited bores for farmers in the ACT and adjoining NSW, supervised drilling the bores and conducted pumping tests. I added my fieldwork observations to the geology of Canberra that had been published by Dr. A. Opik in 1954. Dr Opik had been the Professor of Geology at the University of Estonia and was a world authority on Trilobite fossils and he migrated to Australia after Russia invaded Estonia in 1939.

I had no understanding of the geology of Canberra where rocks had been deformed by complex folding and faulting and minerals had recrystallized to form low grade metamorphic minerals. When Melbourne University opened a Geology campus under Professor David Brown in Canberra in 1960, I was the first post-graduate student. I supervised practical work, attended all undergraduate lectures by Bruce Chappell,  Alan White and Mike Rickard and completed my Master’s thesis on the Farrer-Hoskinstown area in NSW in 1965.

Fairey Swordfish
Fairey Swordfish

Professor Brown was in UK at the beginning of World War II and was a pilot on Swordfish aircraft that attacked the Scharnhorst and Gneisenau with torpedoes as they steamed through the English Channel from Brest to Hamburg. After the war he translated the Geology of Russia into English.

Lake Burley Griffin

Excavations for Lake Burley Griffin began in 1960 and the entire lake floor was excavated to a depth of at least two metres to provide sufficient clearance for boat keels. Another reason given for this was that mosquitoes would not breed nor would weeds grow at such a depth. Clearing of vegetation removed trees from the golf course and along the river, and houses.

At least 382,000 cubic metres of topsoil was excavated and stockpiled for use at several public parks and gardens, including the future Commonwealth Park on the northern shore. It was also used to create the six artificial islands including Springbank Island. The island was named after the former Springbank Farm that was situated there. Land excavated to create a sailing course at Yarralumla was used to create the thematically-named Spinnaker Island to its north, while excavated stone was moved beside the Kings Avenue Bridge at the eastern edge of the central basin to form Aspen Island.

Rock on which the dam was to be built.

King’s Avenue Bridge construction
King’s Avenue Bridge construction

The photo shows the Southern end of Kings Avenue Bridge under construction with Australian War Memorial at far left and Mt. Ainslie, 1961

Site testing for both the Commonwealth Avenue Bridge (310 m and the Kings Avenue bridge took place during late 1959 to early 1960. The construction of the Kings Avenue Bridge (270 m) began in 1960, followed by Commonwealth Avenue Bridge the year after. They were designed to allow the passage of recreational sailing boats with tall masts.

Vertical retaining walls were built in the Central Basin, some beaches and grassy slopes were constructed and the natural foreshores were retained elsewhere.

Scrivener Dam

The dam was completed in 1964 and named after Scrivener. It was a monument to the man who first suggested the region as the most suitable for the new Australian Federal Territory. The dam’s purpose is to form the famous recreational water feature known today as ‘Lake Burley Griffin’ by effectively filling the floodplains of the Molonglo River on the ‘Limestone Plains’.

LakeBurleyGriffin5

A number of geophysical traverses were shot across the valley and a site was chosen for the dam near Government House, Yarralumla. At the dam site clearing of vegetation and soil exposed the rock on which the dam was t o be built. Three major faults crossed the channel and a low angle fault sloping downstream indicated that the central section of the dam would be built on a block that could slide downstream. This was overcome by angling anchor cables upstream through the block.

Work on the lake and dam began in September 1960 and moved faster than expected, due to a drought. However when the dam was finished, nature took longer than expected to fill the lake. For nearly seven months there was just a trickle of water and a few pools which attracted mosquitoes—as the critics had predicted. A rowing championship scheduled for April 1964 looked doomed. Then the drought broke and the rains came. The lake filled in a few days uniting the two halves of the city to give shape and character to the Central National Area. Canberra was never again described as two villages separated by a floodplain

LakeBurleyGriffin6

The concrete gravity dam is 33 metres high and 319 metres long with a five bay spillway controlled by 30.5 metre wide, hydraulically operated fish-belly flap gates with a total discharge capacity of 8 500 cubic metres a second. The German designed and built fish-belly gates are rare in Australia and allow for a precise control of water level. This is important in a recreational and ornamental lake because good water-level control eliminates a dead area between high and low water.

It took 55 000 cubic metres of concrete to build the dam. The maximum wall thickness is 19.7 metres. The dam holds back 33 million cubic metres of water with a surface area of 664 hectares (approximately seven square kms). The lake has a shoreline of 40.5 kms (with a recreational walking/cycle track around it) and is 11 kms long and up to 1.2 kms wide. As well as providing a recreation resource, the dam and lake have created important wetland habitats for native fish, birds and wildlife.

The dam provides flood control for the Molonglo-Queanbeyan section of the Murrumbidgee catchment and will be able to accommodate a one in 5 000-year flood. The only time in the dam’s history that all five gates were opened was in the flood of 1976.

Lake Burley Griffin from Mt. Ainslie
Lake Burley Griffin from Mt. Ainslie

E.G. Wilson,   8/07/2015

Googong Dam lies to the south of Queanbeyan, NSW, and is a water supply dam for Canberra.

Googong Dam is a minor ungated earth and rock fill dam with a clay core and a concrete chute spillway plus a nearby 13 metres (43 ft) high earth fill saddle embankment. It dams the Queanbeyan River upstream of Queanbeyan in New South Wales, Australia. The dam’s purpose is to provide a water supply for Canberra and Queanbeyan. The impounded reservoir is called the Googong Reservoir.

Googong Dam was created through enabling legislation enacted via the passage of the Canberra Water Supply (Googong Dam) Act, 1974 (Cth).[1]

Completed in 1979, the Googong Dam is located approximately 5 kilometres (3.1 mi) south of the town of Queanbeyan on the lower reaches of the river. The dam was built by Thiess based on designs developed by the Commonwealth Department of Construction; and is now managed by ACTEW Water.

The site for a dam on the Queanbeyan River had been identified and geophysical traverses were carried out by the Bureau of Mineral Resources in the 1950’s.  A cable was strung across river and a bosun’s chair used to cross to the other side of the river. The Supervising Geophysicist was Willy Weibenga, an irascible Dutchman, and Willy decided to go to cross the river on the bosun’s chair.  When he was halfway across, they disconnected the rope and Willy was unable to pull himself back. He remained suspended over the river gesturing and yelling curses in Dutch for a considerable period of time, and Charlie Braybrook and his mates relaxed and enjoyed the spectacle. The dam site and the catchment had been mapped by Mike Furstner, another Dutchman, before he resigned and went to Bougainville Mines. Foundation for the dam was irregularly jointed rhyodacite and  for the spillway in a nearby saddle was granite

The Engineer in Department of Works who designed the dam was Arne from Finland, whose surname I cannot remember.  Because the town of Queanbeyan was downstream, the safety of the residents had to be considered. Flooding might breach the dam walls during construction and send a wall of water downstream.

Construction

The first task was to construct a diversion tunnel for the river whilst the dam was constructed.   This was uneventful, apart from the initial opening of the tunnel where the enthusiastic powder monkey used too much gelignite and blew rock debris 50 metres across the river.  The site was cleared of all soil and debris with high pressure hoses.

GoogongDam1

The Googong Dam was to be an earth and rock fill dam. Joints in the underlying rock allow water to seep through and have to be sealed with a slurry of bentonite and cement known as grout.

A Curtain Grout establishes an impenetrable barrier along the centre line of a dam by pumping grout into deep holes.  A Blanket Grout seals joints beneath the dam by pumping grout into shallow holes.

GoogongDam2

The core must be bonded to clean rock with clay leaving no gaps whatsoever. Clay is then added and consolidated with rollers. If the bonding is slipshod then water will percolate through the foundation and the dam will fail.

I was in Idaho in 1974 when the Bureau of Reclamation was building the Teton Dam.  We were led over the site and saw the workmen setting clay on the rock and it was clear that they were not making a satisfactory bond between the clay and  rock.  As visitors we could not criticise but knew that the dam would fail which it did catastrophically in June 1975.

In the USA, the Corps of Engineers were responsible for building concrete dams in mountainous areas, and the Bureau of Reclamation for constructing earth and rock fill dams on the plains.  The Bureau of Reclamation ran out of sites for dams on the plains, and ventured into the foothills for the Teton Dam with disastrous result.

Clay core Windamere Dam

GoogongDam3

 

Teton Dam fails spectacularly

GoogongDam4

 

The Department of Works decided that they would construct the lower portion of Googong dam as standard earth and rock fill up to the point where failure of the dam would not endanger the town of Queanbeyan. Construction above that level had to ensure that the dam could be overtopped but would not fail. This was achieved by anchoring the downstream rock fill with a network of steel mesh. Three days of torrential rain filled the reservoir and overtopped the dam during construction, and it did not fail. I remember sitting on the abutment with Arne and watching the water pouring over the top of the dam and gushing through the diversion tunnel. (see photo below).

The dam was completed without problems and a spillway was constructed through an adjacent saddle.

Water overtopping Googong Dam during construction

GoogongDam5

Googong Dam Spillway

GoogongDam6

Successive flood events in 1978 and through the 1980s resulted in extensive erosion in the unlined section of the spillway chute. Staged remedial works were undertaken in the 1980s to protect the eroded structure, and increase in the capacity of the spillway, to meet extreme flood events.

The dam wall height is 66 metres (217 ft) and is 417 metres (1,368 ft) long. At 100% capacity the dam wall holds back 121,083 megalitres (4,276.0×106 cu ft) of water at 663 metres (2,175 ft) AHD. The surface area of Googong Reservoir is 696 hectares (1,720 acres) and the catchment area is 873 square kilometres (337 sq mi). The ungated concrete chute spillway is capable of discharging 10,500 cubic metres per second (370,000 cu ft/s).[2][4] Successive flood events in 1978 and through the 1980s resulted in extensive erosion in the unlined section of the spillway chute, including a large erosion hole, up to 19 metres (62 ft) deep and 25 metres (82 ft) wide, in the upper part of the spillway chute. Staged remedial works were undertaken in the 1980s to protect the eroded structure. Remediation of spillway facilities occurred during from 2006 through to 2010 that resulted in an increase in the capacity of the spillway, construction of walls in the spillway chute extension up to 17 metres (56 ft) high, and a range of other enhancements to meet extreme flood events.

E.G.Wilson,   01/07/2015

 

The first lecture I attended on Geology at Queensland University was delivered by Professor Bryan on the Grand Canyon.

The landscape is geologically young, being carved within just the last 6 m.y. when the East Pacific Rise intercepted the coast of California and uplifted the Basin and Range blocks to form the Rockies.

Three “Granite Gorges” in the bottom of the canyon expose crystalline rocks formed during the early-to-middle Proterozoic Era (late Precambrian). They were originally deposited as sediments and lava flows, and were intensely metamorphosed about 1,750 million years ago. Magma rose into the rocks, cooling and crystallising into granite, and welded the region to the North American continent.

Rocks exposed in the Grand Canyon range in age from 1840 million years old (m.y), to 270 m.y.  The 3,500 feet walls of sedimentary rock display a largely undisturbed cross section of the Earth’s crust extending back some two billion years.

GrandCanyon1

Vigorous cutting by the snow-fed Colorado River carved the Canyon and widening is held in check by the region’s dry climate.

GrandCanyon2

Kaibab Bright Angel Loop

GrandCanyon3

I visited the south rim of the Grand Canyon in 1996. I was aged 73 at the time and had a replaced left hip and two replaced knees. I started from the South Kaibab Trailhead down the Kaibab Trail with a stout walking staff. The steps were over one foot (30 cm) deep and I continued until I reached the terrace in the Tonto Group at a depth of about 3,000 feet. On the way I was passed by a train of mules carrying those who preferred to do their sight-seeing the easy way. I turned left on to the loop trail (shown in purple on the sketch above) to take me across to Indian Gardens, another five miles and on this last stretch I ran out of water.  When I arrived at Indian Gardens, I lay on a bench exhausted and dehydrated and Kath poured water over me and then had lunch.  We climbed back up the Bright Angel Trail which is a fairly gentle climb on a path with no steps in the midst of a thunderstorm with hail the size of golf balls. I slept well that night..

E.G.Wilson, 23/06/2015