By ERWIN CHLANDA
The Alice Springs Water Allocation Plan 2016-2026 released last week is a monument to government neglect and a denial of the town’s right to grow.
Nothing of note has been done in a decade to increase our knowledge about our most important resource, the aquifers around us from which we draw practically all our water.
The plan makes no bones about it: It reports repeatedly that the knowledge continues to be limited, and it consequently makes no fundamental change to what it orders the town must do with respect to water use.
Despite much debate, sometimes heated, about the extent of and volume in the Amadeus Basin, the government has spent no significant money on exploration drilling that could expand our knowledge of the basin and give the town more water for its future development.
Allocations from the smaller individual alluvial aquifers around town are based on estimated average annual recharge.
Says the plan approved by the former Resources Minister, Willem Westra Van Holthe: “Since 2007, no revision of previous water availability estimates has been undertaken, and there have been no major adjustments made to the allocations available within the Management Zone Area.”
And: “This resulted in an agreement to limit water use from the Amadeus Basin Aquifers to no more than 25% of estimated groundwater storage over the next 100 years.”
And: “There are many knowledge gaps which remain and are identified in the plan.”
So, we could only be dished up the same old, same old: “The water drawn from the Amadeus Basin Aquifers is estimated to be between 10,000 to 30,000 years old and contemporary recharge is minimal in the context of the resource.
“This water resource is therefore considered a non-renewable water resource. The current water extraction regime acknowledges that this resource is effectively being mined in order to sustain the growth of the population of Alice Springs.”
When the plan says it is “is informed by the best available science” the emphasis clearly needs to be on “available”.
But there is hope: The plan – in force now for 10 years with a review after five – “should be considered a living document” so if exploration is finally stepped up, changes are possible.
In what sounds like an attempt at irony the plan says: “Community consultation revealed a common understanding and acceptance that a portion of the water resources of Alice Springs is essentially being mined.” As if the community had a choice in the absence of significant fresh information based on exploration.
“In the context of an unsustainable use, the community did not consider the term ‘sustainable groundwater yield’ to be appropriate – the preferred term to describe the rate of groundwater depletion is ‘maximum allowable yield’.”
The plan makes reference to the “non potable supply from the Alice Springs Water Re-use Project” – drawn from the sewage ponds.
The plan says: “This project remains under the direction and control of Power and Water Corporation.
“The plan acknowledges that it is not the role of the Department of Land Resource Management to deal with source substitution for potable or non-potable reticulated water within Alice Springs; but it does provide for the allocation of water injected into the aquifer by this scheme as part of the consumptive pool.”
How come the plan gives no reason for why this facility – a potential prime source of water, and which evaporates billions of liters a year – should not become part of the government planning for this precious resource?
The water control district covers an area of 8,200 sqkm around Alice Springs which has a residential population of 28,449, of whom 18.6% are Indigenous (ABS 2011).
The surface catchments and groundwater systems of the district are interconnected – flows in the Todd River provide recharge to the Alice Springs Town Basin, Inner Farm Basin and Outer Farm Basin; and flows in Roe Creek, a tributary of the Todd, recharge the Wanngardi Basin and to a lesser extent the Mereenie aquifer.
The district has an arid climate, with variable temperatures:–
• average summer maximum 35 degrees Celsius for three months of the year;
• winter night-time temperatures fall below 0C;
• mean monthly minimum temperature ranges from 4C to 21C;
• mean monthly maximum temperature varies from 19C to 36C;
• typical variation within a day of 15C-20C.
Rainfall is highly variable, which results in periods of extended drought, occasional years of higher rainfall, and rare years of very high rainfall such as 1974 and 2010, says the plan.
Average annual rainfall at the Alice Springs airport is 280 mm, and is highly variable from year to year.
In 2009 the total rainfall was 76.8 mm, and in 2010 the total rainfall was 770 mm.
On 31 March 1988, 204.8 mm – more than two thirds of the average annual rainfall – fell in a single day, resulting in the highest flood in the Todd River since contemporary records began in the 1960s.
Flows have occurred in the Todd River 160 times since 1972.
“Pan evaporation” is very high, at about 3000 mm (that’s three metres) per year, suggesting that much of the rainfall in the region is returned directly to the atmosphere – together with water in the Power Water Corporation’s sewage plant.
Says the plan: “Although it is anticipated that temperature and therefore evaporation will increase in the district, an increase in intensity of storm events projected under current climate change modelling may also increase recharge to the groundwater resource.
“When the plan is reviewed, the latest climatic data will be used to take account of information on projected future climate change.”
At present no more than 5% of any river flow at any time can be extracted for consumptive use (stock and domestic) from any river or watercourse.
Cultural use of water considered in the plan includes recreational visits to places such as Simpsons Gap, the Ilparpa claypans, Redbank and Wigley Waterholes and places along the Hugh River.
It also includes sites such as the Telegraph Station waterhole and Owen Springs “which were important to the history and development of Alice Springs as a town”.
Says the plan: “Cultural needs also encompass the values given to water sites and their associated ecosystems in Arrernte culture where many permanent and some temporary water sources such as claypans, soaks, waterholes, rockholes and springs were vital to the existence of a pre-settlement culture and continue to be deeply embedded with spiritual and cultural significance.
“The entire Todd River is a site of major significance to Mpwartne custodians and other Arrernte people. All large River Red Gums along the banks and in the bed of the river are sacred sites. In addition, there are a large number of other sacred sites located within, on the banks of, or immediately adjacent to the Todd and Charles Rivers.”
In an apparent reference to the long-discussed Todd River flood mitigation and/or recreational dam, the report says: “Any construction of dams or water-intercepting / diverting works may require a permit under other Acts (particularly the Sacred Sites Act).
“As such it is the land owner’s responsibility to ensure all appropriate permits and approvals have been granted before any construction begins. This would include ensuring the proposed works comply with the Water Act.”
The plan says given the very limited water resources available at White Gums, it is unlikely any new bore construction permits will be issued in or upstream of the White Gums area of the Wanngardi Subdivision, other than for replacement of existing bores: “It is believed that the Wanngardi Basin in the White Gums area could not sustain an expansion of current water extraction from the Basin. It is likely that any new subdivisions in this area will need to access reticulated water supplies to ensure reliable supplies.”
The plan says in its development the department “engaged with the general community and sought advice from the Alice Springs Water Advisory Committee. Community consultation is a key part of the process … the public and key stakeholders were invited to participate in the planning process, by attending information sessions”.
The plan does not reveal the extent to which the “general community” and indeed the advisory committee members availed themselves of these opportunities, what the meeting numbers and attendances were, and what came out of these meetings. Anecdotal information suggests that the yield was poor.
According to Water Resource Planner Kate Heppner “the Minister for Land Resource Management is keen to see the establishment of a new Alice Springs Water Advisory Committee”. [UPDATE: She says that was a reference to Mr van Holthe.)
PHOTOS from top: The original “Alice Springs” at the Telegraph Station; the footbridge in a major flood of the Todd River; one of The Centre’s beautiful gaps.
Ms Heppner says the new plan allows additional extraction of 800ML/year of better quality water (<500 TDS), and 2000ML/year of poorer quality water (500-1000 TDS) from the Mereenie Aquifer System, within the Roe Creek Management Zone for the beneficial use Industry.
“Over the coming year, the intention is to undertake a detailed hydrogeological study of the Mereenie Aquifer, including development of a numerical model,” she says.
Pine Gap’s allocation has consistently been 250 ML/year. The allocations to Rocky Hill were 400 ML/yr from 1996 to July 2007; 1000 ML/yr from August 2007 to October 2015 and 3125 ML/yr from October 2015 to October 2025.
KL = kilolitre (1 kilolitre is 1000 litres).
ML = Megalitre (1 megalitre is 1,000,000 litres).
GL = Gigalitre (1 gigalitre is 1,000,000,000 litres or 1,000 megalitres).
TDS = total dissolved solids.