Recent history of water management in Padthaway 

Groundwater in the Padthaway Prescribed Wells Area is currently managed through the 2001 Padthaway Water Allocation Plan. 

The 2001 WAP was the first water allocation plan to be implemented in Padthaway and recognises that at the date of adoption of the Plan, a significant portion of the Padthaway PWA was over-allocated.
To hold water extraction at current levels while a plan for the sustainable management of the groundwater was developed, a Notice of Restriction was put into place by the then Minister for the Environment, that same year.

The scientific and technical expertise available to the Board, combined with the ‘real life’ experience of the community, has helped the Board to consider all possible options and eventually make the best possible decisions. There is not another area in the South East that is as thoroughly studied and as well understood as Padthaway.

Community consultation to date

The review and amendment of the Padthaway Water Allocation Plan (WAP) is currently in its final stages. A first community consultation (A1 consultation) on issues and options for the review of the WAP was carried out in September 2005. A second round of community consultation (A2 consultation) occurred in December 2006, followed by a newsletter outlining the outcomes of this second consultation. A third and final round of consultation is scheduled for September 18, 2008.

Information Forum – Answering your Questions

An informal information forum has been scheduled for 11 September 2008, from 1 pm - 8 pm at the Padthaway Bowling Club. This meeting is to enable community members to clarify any questions they may have on the options being proposed, in advance of the community consultation meeting. Staff from both the SE NRM Board and the Department of Water Land and Biodiversity Conservation will be available to discuss issues one-on-one and provide further information. You are welcome to drop in at anytime during the meeting time scheduled below.

Consultation Meeting – Expressing your Views on the draft Water Allocation Plan

Community consultation on the draft Water Allocation Plan for Padthaway is scheduled for 18 September 2008, 6 pm – 9 pm, at the Padthaway Bowling Club. The meeting will include a presentation on the contents of the draft Water Allocation Plan and an opportunity to make comment.

Submission of written comments

In addition to the consultation meetings, written comments can be submitted to the Board. Submission forms and fact sheets are available below or in hard copy by calling the SE NRM Board on 8724 6000. The consultation period ends at 5.00pm, Tuesday, 4 November 2008.

The Padthaway Groundwater Management Committee

The Padthaway Groundwater Management Committee was formed in 2002, as part of a range of measures to examine and ensure sustainable groundwater management in the area.

The Committee is composed of community members and Board and DWLBC staff, and provides advice and options for management of the resource to the Board.

The Committee has met over 40 times and has made significant contributions to the draft Water Allocation Plan.

Research in Padthaway

Since the development of the 2001 Water Allocation Plan, studies were initiated to determine the causes of the rising groundwater salinity. In addition, a review of the conditions of the resource and of the amount of water available for extraction was finalised in February 2006 followed by second study in 2007.

These reviews indicate that triggers in water table levels have been exceeded in Management Areas 1, 2A, 2B and 3, while groundwater salinity has increased beyond the limits (triggers) stipulated in the 2001 Water Allocation Plan in all management areas. Though water tables in Padthaway can be considered to be highly responsive to rainfall, overall, salinity values have continued to increase steadily over the last 10 years. In addition, the review has also indicated that in all management areas with the exception of management area 4, the level of allocation exceeds the amount of water available for extraction.

Further information on this study can be accessed from 'A New Understanding on the Level of Development of the Unconfined Tertiary Limestone Aquifer in the South East of South Australia' (DWLBC 2007/11) from the Department of Water, Land and Biodiversity Conservation website.

The Padthaway Salt Accession study was initiated in 2003 by DWLBC and has revealed that there are two mechanisms behind the rising groundwater salinity in Padthaway:

1. Clearance of native vegetation in the Naracoorte Ranges has lead to rising water tables and the leaching of the historical salt load in the soil into the groundwater. This salt has since then moved several kilometres westwards along the natural flow path of the groundwater, into the Padthaway Flat area.
2. Irrigation recycling of drainage water: the project has shown that groundwater salinity increases under flood irrigation, while a significant amount of salt accumulates in the root zone under drip and spray irrigation. In addition, water is recycled along it’s flowpath towards the west and then the north of the PWA.

 The project has indicated that although salt will continue to leach over the next decades, the salt store in the Naracoorte Ranges is finite and can be expected to be followed by fresher recharge. As a result, the study has identified maintenance of groundwater throughflow as a key groundwater management requirement.

Groundwater management in Padthaway – what’s being proposed?

The main policy changes proposed by the draft Plan are explained in the Information Sheets 1-3 posted on 3 September 2008 to all licensees and landholders in advance of 18 September 2008 community consultation, and include:

• Allocation of water according to the community-based proposal for allocation in the Padthaway Prescribed Wells Area
• New management areas proposed
• New trade rules
• Provisions for the protection of groundwater dependent ecosystems. cording

It is expected that the current Notice of Restriction on the level of use will be lifted once the new Water Allocation Plan is in place.

Sustainable levels of groundwater extraction

As a signatory of the National Water Initiative, South Australia is under the obligation to return all over-extracted and over-allocated systems to sustainable levels of extraction.

Since the last community consultation, the Board has continued to meet with community and stakeholder groups, as well as the Padthaway Groundwater Management Committee to discuss and develop the best way to ensure resource sustainability, including reducing the level of demand on the resource.

As a result, the Padthaway Grape Growers Association and the Padthaway Flood Irrigators requested Board support in the development of a community proposal to reduce demands on the resource. Subsequent discussions between the Board and the Department of Water, Land and Biodiversity led to the Department engaging Resource and Environmental Management (REM) to carry out a project to determine an acceptable groundwater extraction limit for the Padthaway region.

REM began work in Padthaway in August 2007. The process included working with community, Board and DWLBC representatives to set resource condition limits and discuss scenarios to run through a recently finalised groundwater model of the area, to determine the acceptable level of extraction. REM worked with community representatives, including the Padthaway Groundwater Management Committee (which includes members of the Padthaway Grape Growers Association and the Padthaway Flood Irrigators), as well as representatives of the Limestone Coast Wine Industry Council and the community-based Northern and Central Natural Resources Management Groups. The process provided these representatives with the opportunity to consult with the wider community during the discussions. Community members were also encouraged to contact the members of the Padthaway Groundwater Management Committee to put forward any comments they might have.

The numerical (3D) computer model of groundwater and salinity fluxes in the Padthaway region, has allowed the determination of a sustainable level of groundwater extraction. Together with community representatives, a value of 48,000 Ml/annum has been selected as the Acceptable Level of Extraction.