Kangaroo Island Water Resources Management Update
Kangaroo Island Natural Resources Management Board, March 2012
History of Water Resources Planning on Kangaroo Island
In preparing the Regional NRM Plan for Kangaroo Island, the Kangaroo Island NRM Board (the
Board) was required to develop policies for the management of water resources on Kangaroo
Island.
The initial Draft Kangaroo Island Region NRM Plan applied the State NRM Plan (2006)
guideline for the management of surface and watercourse water, which is contained in Appendix
B Water allocation and management: Guidelines. This guideline which is often referred to as the
25% Rule was applied to the whole island.
During the public consultation period for the Draft Kangaroo Island Region NRM Plan it became
clear that the application of the 25% rule was not supported by the community, as it was thought
to be far too restrictive and unnecessarily limited development.
In response, the region was split into two Zones (A and B) based on rainfall. Sub-catchments
with average rainfall 600mm or greater were placed in Zone A and sub-catchments with
average rainfall less than 600mm were placed in Zone B.
Different policies for the assessment of Sustainable Use Limits (SUL) were applied to each
Zone. Rocky River flow data was used for Zone A and the SUL calculated were based on the
assumption that flow generated under natural conditions (total Native Vegetation cover) was the
environmental flow requirement. At the time this method was being proposed for inclusion in the
Plan, the Department for Water Land and Biodiversity Conservation expressed concern that the
use of the method had no scientific basis.
As a result of this concern the Middle River catchment, from which Kangaroo Islands public
water supply is sourced, was excluded from Zone A and a 20% precautionary reduction of the
SUL was applied across the remaining Zone A catchments. The 25% rule was applied to
catchments in Zone B and used Middle River Reservoir and Mount Lofty Ranges data to
determine the SUL.
The Regional NRM Plan 2009 (the Plan) was adopted in September 2009. The Plan stipulated
that a Water Resources Management Taskforce would be established to assess the water
policy set out in the Plan and the scientific basis of the policy, and states that ’as part of the
work of the taskforce there will be an independent scientific review of ‘Method A’ to ensure its
application adequately protects existing users and environment in Zone A’.
The Water Resources Management Taskforce was established in 2009 and includes
representatives from the Board, State and Local Government, Kangaroo Island agricultural and
environmental groups and private forestry.
Independent Scientific Review of the Kangaroo Island Natural Resources
Management Plan Water Resources Policy
In May 2010 the CSIRO were contracted to conduct an independent scientific review of all water
resources management policies contained in the Plan. A draft CSIRO Report was received in
November 2010, with the final CSIRO Report received on 11 July 2011.
The key conclusions of the CSIRO review where that;
• Based on the rainfall attributes and limited modelled streamflow data in Zone A and Zone B
the delineation of these zones appears to be reasonable.
• The SUL calculated using Method A is not based on established methods. A number of
assumptions used in this method have not, or cannot, be substantiated with available data.
There is no basis to assume that mean annual flow from a pristine forested catchment should
be the required minimum flow in adjacent cleared catchments under natural conditions.
• Neither Method A or B seem to provide enough safeguard against diversion of water needed
to maintain the aquatic and riparian ecosystems during dry years.
• The recent past (since mid-1990s) has had a drier hydrological regime than the long-term
average conditions, and that falling trends of runoffs in all Kangaroo Island catchments together
with falling trends in recent rainfall imply that present streamflows are not representative of the
past streamflows.
Climate and streamflow data post mid-1990s is recommended for any future SUL
calculations.
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• The SUL estimates can be improved with detailed data and/or more appropriate models.
• Two additional stream gauging stations in addition to those already suggested in the National
Action Plan for Water Quality and Salinity should be installed. A meteorological station capable
of measuring potential evaporation data should also be installed.
• The Board needs to continue its long term monitoring of rainfall and streamflow data stations.
• Until sufficient observed data is available, the use of modelled streamflow to derive SUL is
reasonable.
Water Resources Management Taskforce Recommendations
The Water Resources Management Taskforce subsequently reviewed the CSIRO report and its
conclusions and made the following recommendations to the Board on how to proceed with
water resources management policy development on KI.
Recommendation 1.
That the Board:
1.
Notes that the CSIRO report does not support the continued use of Method A as the
assumption that annual flow of a fully vegetated catchment is appropriate minimum flow
for adjacent cleared catchments with possibly similar rainfall, geology and topography is
flawed;
2.
That the Water Resources Task Force does not believe the level of risk currently
presented requires an immediate change in Method A in Zone A;
3.
Seeks a more thorough exploration into alternative methods being applied in other
jurisdictions;
4.
Starts this work immediately to have an appropriate method in place for the next Regional
NRM plan.
Recommendation 2.
That policy zones A and B are retained until the next review period.
Recommendation 3.
That local data is used where possible, if not available draw on available data but always use
long term data to reflect climate variability.
Recommendation 4.
That in developing water policy the Board:
1. Recognise the effect of climate variability, in particular the relationship between run-off
and rainfall, and to review this every 5 years;
2. Examine climate change predictions in a more strategic way to consider the potential
level of risk to water resource planning in the Region.
Recommendation 5.
That in conducting water resource planning:
1. Longer term data is utilised; and
2. At end of each 5 year period, the Board reviews the period of data used to inform the
planning process for the next 5 years.
Recommendation 6.
The long term vision for the development of water policy across KI requires:
1. Environmental water requirements to be quantified [this will involve identifying the
pattern of water flow needed to sustain plants and animals living in and around the Islands
watercourses];
2. Sophistication of water management beyond quantity considerations only;
3. Policy decisions based on triple bottom line balance of priorities; and
4. That it may be that not every catchment has the same blanket policy.
Recommendation 7.
That to achieve a long-term vision for the water policy, the Board needs to consider the status of
and risks to the [water] resource, including climate change projections regardless of the method
or approach used.
If a tailored approach is preferred, the following data will need to be available to ensure equity of
the resource across catchments:
1. Collection of data on water use;
2. Environmental asset and water requirements;
3. Land use planning and projections; and
4. Modelling.
Recommendation 8.
That the Board maintains the status quo with the view to reviewing and refining current
methodologies by:
1. Seeking a more thorough exploration into alternative methods being applied in other
jurisdictions; and
2. Immediately commencing work towards an appropriate method
KI NRM Board Position on CSIRO Report
The Kangaroo Island NRM Board has received the findings contained in the CSIRO report and
has endorsed the recommendations made by the Water Resources Taskforce in full.
While alternative methods for determining sustainable water use limits in Policy Zone A are
investigated the Board will continue to apply Method A.
The Board has commenced working towards the implementation of the Taskforce
recommendations and have begun discussions with the Department for Water with regards to;
1. The monitoring requirements needed to allow improved water resources management
decision making; and
2. Exploration of alternative approaches to water resources management being applied in
other jurisdictions.
The Board will ensure that the community and all other stakeholders are consulted and provided
ample opportunity to comment on any policy changes being proposed by the Board during the
public consultation period that will occur as part of the Boards 5 year review of the current NRM
Plan.
If you have any queries about the contents of this communiqué or any other water related
matter, please contact Joseph Sullivan, (NRM Officer-Water) on 08 8553 4438 or 0400 509 053
or you can write to the Board at 37 Dauncey St, Kingscote, 5223.
Yours sincerely
Bill Haddrill
REGIONAL MANAGER