MacFarlane water allocation: Letters from department, Bureau of Metereology







Erwin Chlanda


Alice Springs News Online

Mob 0418 890040


Begin forwarded message:

From: Edwin Edlund <>

Date: 22 August 2013 12:29:31 PM ACST

To: ‘‘” <>

Subject: McFarlane water licence


Erwin, you may attribute the following to Department of Land Resource Management water resources executive director Matt Darcey:


“The Water Resources Division within the Department of Land Resource Management (DLRM) considers the best information, data, records and modelling available from reliable and reputable sources, before providing advice to the Northern Territory Controller of Water Resources on which he can base any informed decision.


“New and updated data along with refined modelling has meant the Controller of Water Resources is confident that an increase in the previously specified consumptive pool, meaning the allocation of more water, won’t have a negative impact to the environment.


“The 2011 draft Water Allocation Plan (WAP) for the Tindall Limestone Aquifer, Mataranka set the consumptive pool in each year as the lesser of 20% of annual recharge or 19,500ML/year.  This maximum cap for the annual consumptive pool was equivalent to 15% of the modelled average recharge over 109 years between 1900 and 2008.


“In the course of finalising this draft WAP, DLRM has identified some matters that warrant further consideration in regard to the setting of the annual consumptive pool for the aquifer.


“As shown in the Background Document to the WAP, over the 109 years between 1900 and 2008, recharge and river flows were consistently higher after 1970 than at any times throughout the preceding period from 1900 to 1969.  Average modelled recharge for the period 1900 to 1969 was 103,000ML/year.  The modelled average for the period 1970 to 2008 was 180,000ML/year.


“This means that the maximum cap on the annual consumptive pool based on the overall average for the total period from 1900 to 2008 would not be particularly relevant to either the relatively drier period of the first 70 years, or to the relatively wetter period of the final 39 years.  The maximum cap would rarely if ever be reached in the drier 70 years.  In the more recent, wetter years, the maximum cap would apply in most if not all years but would be less than the 20% of recharge potentially available for environmentally safe extraction.


“Since releasing the draft WAP for public comment, staff from DRLM and the Bureau of Meteorology (BOM) discussed the use of historic data in the modelling and agreed (informally) that the current climate/weather is most likely to be similar to what has been experienced during the past 30 years.


“This is consistent with BOM’s letter to AFANT (see pdf attached) which says that using the most recent 30 year period is a useful indicator of current variability – essentially using the 30 year period as the context to measure variations of today’s weather patterns and climate.


“Current modelling using all the best available data has allowed for relationships to be established between flow rates at springs within Elsey National Park from changes in groundwater levels.


“Using the refined model, an estimated average annual recharge of 180,000ML for the past 40 years means that the aquifer should sustain an average annual consumptive pool of up to 36,000ML for the next 10 years, as no more than 20% of annual recharge can be extracted from the aquifer.


“The Controller of Water Resources and DLRM remain confident in computer modelling that uses the best data and records available and will continue assessing each licence application on its merits while also taking the cumulative effects of each new licence fully into account.”




Edwin Edlund

Media Manager

Communications and Media


Department of Land Resource Management

Department of Arts and Museums

Department of Sport and Recreation

Parks and Wildlife Commission of the NT

Northern Territory Government

p. 08 8999 4730 f. 08 8999 4723












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Erwin Chlanda, Editor