Diversion Dam gate (Kununurra) raised for maintenance with “stop logs” inserted behind to retain water. The Water Corporation refurbish (maintain) at least 2 gates each year.Without the large stop logs inserted water would discharge at a rate of 15,000 litres per second for every 100mm the gate is raised. (each gate is nearly 15 metres wide and 13 metres in height and weighs over 96 tonnes)
Sections of the roadway on the Diversion Dam are removable to allow giant “stop logs” to be lowered behind the gates. Once these stop logs are in place the Water Corpoiration is able to raise the large radial arm gates (each gate is nearly 15 metres wide and 13 metres high and weighs over 96 tonnes) to allow the continual refurbishment of the gates. During maintenance, bearings and seals are replaced, sandblasting and painting carried out and general overall maintenance is carried out.
Even during the “dry” season large volumes of water are discharged (wasted) out to sea. Of 11,000 gigalitres in Lake Argyle only 300 gigalitres (yes 300) of water are used. The remainder is wasted or released to “maintain” the wetlands. These “wetlands” did not exist 43 years ago. They have developed as a result of damming The Ord River, which was a series of isolated pools in the off season prior to 1963. Now under international Ramsar Wetland agreements there is a requirment to maintain the wetlands by releasing water that could be better used.
No visit to the East Kimberley is complete without a trip to, or a flight over Lake Argyle. Formed by the building of the Main Ord Dam in 1969-72, Lake Argyle contains water equivalent to up to 35 times the volume of Sydney Harbour. The dam wall is a mere 353 metres in length but the water of Lake Argyle can stretch back100 kilometres behind the clay and rock wall. After a “wet” in 2000 in which our rainfall was nearly double the annual 800 mm, Lake argyle at one stage overflowing the spillway by 7.8 metres, overflowed continuously from Christmas 2000 to Christmas 2001
The “Sleeping Buddha” one of many iconic landmasses in Kununurra is visible from almost any where in and around the Ord River Irrigation Area nestles on the edge of Lake Kununurra. The head of the buddha (right hand end) is also known as Elephant Rock as viewed from Lake Kununurra where a trunk and tusks of an elephant is readily recognisable.
The East Kimberley Regional Airport at Kununurra, owned by the Shire of Wyndham East Kimberley was a few years ago one of the busiest airports in Western Australia. The domestic terminal, refurbished and doubled in size in 1992 is the front of a busy airport that is home base to about 60 light aircraft and 25 helicopters. Regular jet services connect Kununurra to Perth and Broome and a every day turboprop service allows access to Darwin. Before the cessation of services by Ansett, at least one jet service both north and south connected Kununurra with Perth and Darwin. At the height of the visitor season up to 3 jet services a day served the area.
Ivanhoe Crossing, one of the favourite visit spots on our 2K-ORIA tour was constructed in its present form in 1952 at a cost of just 25,000.00 Pounds ($50,000). Each of the 125 culverts under the crossing is formed from 6 individual 44 gallon (205 litre) drums welded together. Four workers under the direction of Bill Wright while living in tents on the river embankment completed the very much labour intensive task in 2 dry seasons and on budget.
Ivanhoe Crossing in 1952. The large sandbar in the distance (we are looking east towards where Kununurra is today) about 4 metres deep, 500 metres in length and about 400 metres wide was deposited here in one “wet” season and disappeared the next. The Crossing today appears very different with a large and expansive growth of vegetation changing the appearance dramatially.
Sandalwood is one of the newer crops being grown in the ORIA. Here we see a tiny (about 150mm high) sandalwood (Santalum ) seedling just planted in the field with its “pot host” Altrananthera nana at foot. (Sandalwood has a series of three hosts throughout its 15 year growth life before the tree is harvested for the highly priced heartwood containing sandalwood oil). Photograph taken with the kind permission of Zoe Higgins at Integrated Tree Cropping, Kununurra, firstname.lastname@example.org)
The flower of the pest plant Calotropis. The leaves and branches contain a highly caustic sap that contains some pharmaceutical alkaloids. Attempts were made some years ago to cultivate the Calotropis to recover the alkaloids but all trials failed. The flower is however, quite attractive and close up is orchid like.
A large Boab tree (Adansonia gregorii) growing near the Diversion Dam in Kununurra. Boabs are usually devoid of leaves during the “dry” with the appearance of leaves signalling the approach of the “wet”. After the highly scented white flowers have been pollinated the fruit or BOAB NUTS develop. The nut (fruit) as well as containing the seeds also contains a “nutty” pith that is used to flavour chocolates that are produced by Melissa Boot, an entrepenarial Kununurra artist.