Transcript Climate change and water quality projects at SA Water

Future Climate: What does
it mean for reservoir water
quality?
WRA 1050/ WaterRF 4468 Comprehensive
assessment of the Impacts of Climate Change on
Reservoir Water Quality in a Range of Climatic
Regions
Leon van der Linden
SA Water, Research and Innovation
Water RA Forum, WA, November 2013
Business Issue: Problem Statement
Climate change
• Water security (quantity and
quality; supply and demand),
operational costs and asset
longevity.
• Impacts SA Water source waters.
• Presents additional challenges to
planning and operations.
“Managing
these
changing
environmental conditions pose
challenges in unchartered
territory and require long-term
planning based on scientifically
sound research.” - Denise Kruger,
Water Research Foundation,
Chair of Board of Trustees.
Climate: Variability and Change
• Variability: interacting geophysical
phenomena
– Our understanding is still
developing
• Instrumental record has limited
temporal and spatial extent
• Proxies: flood debris, germination
events, etc
• Global circulation models still
have major uncertainties; the
science is underpinned by real
data
• Understanding the past and
present weather is
challenging
Projected temperature rises for South Australia
2020
2050
2080
Projected precipitation for Southeastern Australia
2020
2050
2080
Post, D., Chiew, F., Teng, J.,
Wang, B. & Marvanek, S.
(2012) Projected Changes
in Climate and Runoff for
South-eastern Australia
Under 1 °C and 2 °C of
Global Warming. A SEACI
Phase 2 Special Report.
Potential climate change impacts to the water business
• Cost
–
–
–
–
Assets / Investments
Energy (pumping, desalination and price)
Coagulants
Disinfectants
• Compliance
– Pathogens / DBPs / Toxins
– Outfalls
– Greenhouse gas emissions
• Customers
– Aesthetics / tastes and odours
– Demand
Water
Quality
Impacts
Projects on climate change impacts on water quality
• Water Research Foundation / Water Research Australia:
– Comprehensive assessment of the impacts of climate change on
reservoir water quality in a range of climatic regions
– VT, NCKU, UA
– Literature review; integrated modelling analysis
• Goyder Water Research Institute:
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–
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An agreed set of climate projections for South Australia
Task 4 – Development of an application test bed
UniSA, SARDI, UA, FU, DEWNR
Reservoir model sensitivity analysis; downscaling product evaluation
Potential climate change impacts on water quality
Elevated temperatures
Impacts on catchment biogeochemistry
Increased stratification
Release of ions from the sediments
Growth of cyanobacteria
Less frequent but more intense rainfall
Altered flow regimes
Increased transient inputs of:
sediment
pathogens
organic matter
WTP
Skilled GCM
Climate
Projections
Change Statistics
Distributions
Variable correlation
Weather
Generator
Historically valid coupled model
Catchment
Data
Hydrological
Model
Reservoir
Data
Hydrodynamic
Model
Water quality
scenarios
Water quality
Model
Catchment and
Reservoir
Planning Options
Risk assessment
Expert
knowledge
Climate change impacts
on water quality
Model Sensitivity – ELCOM-CAEDYM – Happy Valley Res.
Overlay: Empirical sensitivity of monthly average chlorophyll to temperature anomaly
Integrating impacts into risk management framework
Risk Matrix - Defines management vigilance
Anticipated Outcomes
• Identification of risks to water quality
– Reservoir stratification
– Rainfall extremes
– Catchment impacts
• Develop methods to quantify risks
– Contribute to corporate risk management
• Provide information for long term planning
– Comprehensive climate change scenarios
– Quantified changes in risk