1. Groundwater as a “drought reserve” in a drying climate
Presentation to the University of Melbourne Law School
Workshop on Water Governance for Resilience
Alex Gardner Faculty of Law, UWA
25/09/14

2. Overview: Reforms for groundwater drought reserve
Orienting South West Western Australia
National water policy reforms
Planning for climate change adaptation
Entitlement holders saving water
Conclusions - groundwater based system

3. 1. Orienting South West WA
Surface water yield 1/4 of 1970
Groundwater makes up around three quarters of water use
Total groundwater use around 850GL/yr (2009 estimate)
Self-supply for gardens, public open space, horticulture, mining, industry is around 700GL/yr
important for public water supply (~150GL/yr and 40% of IWSS)
New alternative sources:
Desalination 150 GL/yr (from 2006)
Recycled water; GWR  28 GL/yr
Demand management
environmental water allocations
frequently breached
Source: CSIRO 2009
25/09/14 3

4. Rainfall trend since 1987 - predicted vs actual4

5. Public water supply strategy
SUPPLY AND DEMAND FOR THE INTEGRATED SCHEME (IWSS)
350
Groundwater Security Strategy
300
Southern Seawater Desalination Plant
Perth Seawater Desalination Plant
250
Groundwater Supply
Surface Water (including trade)
GIGALITRES
200
150
100 50
YEAR
Source: Water Corporation (2013)

6. Groundwater resources declining
Gnangara Superficial
Gnangara Confined
SW Ramsar wetland: declining water table impacts water quality

7. Gnangara Groundwater System
Rainfall
Superficial aquifer well
Confined aquifer well
Bassendean Sand
River
Guildford Clay
ial
Confining Bed au
t l F
ville aquifer ng
arli
ed D
Coastal Limestone
Wetland
Indian Ocean
Superfic aquifer
Caves
Leeder
Confining B
Confining Bed
Yarragadee aquifer
25/09/14

8. 2. National Water Policy Reforms
Current Law (since 2001)
Landholder eligibility to hold licence
No statutory plans or consumptive pool – non-statutory allocation limits
10 yr licences with tradable entitlements
Entitlements = maximum annual volume
Poor water accounting & enforcement
Legal environmental water allocations under EIA law or water licence conditions
National Water Initiative reforms
proposed but constantly delayed since 2006:
Statutory allocation limits and plans for
consumptive pool(s)
Tradable perpetual share entitlements
Environmental water holder
RiWI Act turns 100, 22 Sept 2014

9. 3. Climate change and groundwater planning
Currently no requirement in the RIWI Act to consider climate change risks in groundwater planning (cf Water Act 2007 (Cth))
In practice, limited use of climate change
scenarios in non-statutory allocation plans
This is changing - DoW has new GIS tool to produce ‘future climate’ scenarios for any part of WA, to be used in future water planning.
25/09/14 9

10. Law reform proposal: duty to address climate change
The new water resource management legislation should require the Minister to consider climate change risks in the preparation of statutory water allocation plans and to address those risks in the plan provisions: for example,
declining allocation limits over plan life
zoning areas for no consumptive use,
including by domestic bores
25/09/14 10

11. 4. Groundwater as a ‘drought reserve’
Can groundwater be sustainably used as a
drought reserve in a drying climate?
What regulatory arrangements would best support this?
Case study: groundwater as a drought
reserve for the IWSS public water supply
Regulatory options for entitlements saving water
30/07/14 11

12. The Variable Groundwater Extraction Rule (VGAR) for IWSS
25/09/14 12

13. Failure of the VGAR in a drying climate
Problem: In a declining rainfall trend the VGAR results in sustained high groundwater abstraction, compounding the effects of low recharge on the groundwater system (DoW, 2013)
DoW solution: 5 year, 110GL/yr average extraction for the Integrated Water Supply Scheme.
25/09/14 13

14. Groundwater as a ‘drought reserve’:
- regulatory options for entitlements
Entitlement holders have:
carryover and borrowing rights in suitable aquifers
compulsory ‘banking’ (eg 10% of entitlement) accessible only on ministerial declaration
Department reserves water and auctions short
term licences on ministerial declaration
Independent water holder retains water entitlements in suitable aquifers that it auctions in extreme drought
Managed Aquifer Recharge of recycled water should include a restoration share
26/09/14 14

15. Conclusions for a Groundwater based system
Information challenges – especially modeling
NWI reforms – they are not enough
Long term water resources assessment and climate adaptation planning
NWI flexibility of share entitlements with obligations to plan for climate change
- statutory duties to model, zone and save
Urban water supply – alternative sources
Social and cultural values