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Climate Change and IntegratedWater Management:

Perceptions and Realities

Walter RastDirector, International Center for Watershed Studies (ICWS)

Texas State UniversityVice-Chair, ILEC Scientific Committee

Walter Rast, Director, ICWS & Vice-Chair, ILEC Scientific Committee

“…Eradicating poverty is the greatest global challenge facing the world today and an indispensable requirement for sustainable development. In this regard we are committed to free humanity from poverty and hunger as a matter of urgency.”

Poverty vs. being poor;

SG Kofi Annan: Single greatest thing humanity can do to reduce death and sickness on a global scale was to provide clean drinking water and adequate sanitation;

2Walter Rast, Director, ICWS, Texas State University & Vice-Chair, ILEC Scientific Committee

“…We reaffirm that climate change is one of the greatest challenges of our time…….adaptation to climate change represents an immediate and urgent global priority.”

“…We acknowledge that climate change is a cross-cutting and persistent crisis and express our concern that the scale and gravity of the negative impacts of climate change affect all countries and undermine the ability of all countries, in particular, developing countries, to achieve sustainable development and the MDGs and threaten the viability and survival of nations….”

3Walter Rast, Director, ICWS, Texas State University & Vice-Chair, ILEC Scientific Committee

“…Water is primary medium through which climate change influences our planet, and the livelihood and well-being of its inhabitants….”

Climate change is key driver of change in water availability & use; also interacts dynamically with demographic, economic, social and technological forces;

Water resources among sectors most affected by climate change, via hydrologic cycle; ultimately socio-economic systems via water management efforts.

4Walter Rast, Director, ICWS, Texas State University & Vice-Chair, ILEC Scientific Committee

(7). New Challenges for Climate Change Mitigation and Adaptation: Managing Unintended Consequences: Large wind farms (energy) & migratory bird behavior; sea walls & natural wetlands;

(16). Acting on Climate Change Signal on Frequency of Extreme Events: Many scientific studies confirm climate change can alter extreme event frequency, strength & distribution must adapt to changing frequency;

(21). Managing Impacts of Glacial Retreat: Many glaciers in retreat (Himalayas; Central Asia; Andes) threats to people & ecosystems --> increased flood risks from bursting of natural dams; eventual decrease in dry season runoff in some regions better understanding of hydrological, economic and social consequences needed

5Walter Rast, Director, ICWS, Texas State University & Vice-Chair, ILEC Scientific Committee

Changes in climate amplified in water environment(e.g., few degrees temperature change precipitation changes average river flow & water availability changes (10-40% increase in some regions; 10-30% decrease in others) human and environmental impacts;

Adaptation to climate change translates to achieving & sustaining water resources under conditions of uncertainty(i.e., past not necessarily good model for future predictions; plan for increased, decreased or unchanged water resources)

6Walter Rast, Director, ICWS, Texas State University & Vice-Chair, ILEC Scientific Committee

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All climate changes NOT negative (Economist):• Less severe winters in some areas;• More precipitation in some dry areas; less precipitation in

some wet areas;• Increased food production in some areas;• Expanded population/range for some plant & animal

species adapted to higher temperatures

Adverse Impacts:• Hydrologic cycle (distribution, quantity, timing of

precipitation);• Persistent drought and extreme weather events;• Sea level rise and coastal erosion (unprecedented

magnitude of social displacement);• Ocean acidification

8Walter Rast, Director, ICWS, Texas State University & Vice-Chair, ILEC Scientific Committee

Some impacts reflect water role in human life:• Rainfed agriculture – adapt to new rainfall patterns;• Fisheries – shifts related to changing ecologies

(e.g., temperature)• Human health care systems – new incidences of

disease related to changing ecologies (e.g., cholera, malaria);

• Infrastructure (incl. roads, buildings) – alterations to precipitation and river flow patterns.

9Walter Rast, Director, ICWS, Texas State University & Vice-Chair, ILEC Scientific Committee

Variable Present/Projected ImpactsPrecipitation Increase (~2%/⁰C) in total precipitation; high latitude areas

generally to increase; many low- to mid-latitude areas to decrease; but variable at regional scale

Droughts Increasing in many areas, particularly lower latitudes; decreasing in many high latitude areas; complex patterns

Tropical cyclones Increase in intensity (North Pacific, Indian, Southwest Pacific Oceans); frequency and track changes uncertain

Glaciers and snow cover Continued decrease in glacial mass and snow cover (but not all regions); earlier peak runoff from glacier and snowmelt

Sea level ~0.2 m increase over 20th Century; rise equivalent to 0.3 m/century since early-1990s; IPCC: 0.2-0.6 m by 2100 (upper end may be much higher)

Ocean acidification Mean surface pH projected to decrease from ~8.2 (present) to ~7.8 by 2100

Sea surface temperature Increase by 0.5o C since 1980; continuing to increase

10Walter Rast, Director, ICWS, Texas State University & Vice-Chair, ILEC Scientific Committee

Increasingly Frequent Extreme Weather Events

Flooding in southern Pakistan(AFP, 5 August 2010)

Heat wave and forest fire in Russia(National Geographic News, 12 August 2010)

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Retreating Himalayan Glaciers

(Source: Nagoya University)

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Climate Change Impacts on Water, Ecosystems and Food Production

(IPCC 4th Assessment Report, Climate Change 2007: Synthesis Report, Summary for Policy Makers)13

Changes in hydrologic cycle: Drought vs. Floods;

Floods are most devastating natural disasters, but most pressing problem/impact = Increasing water scarcity

natural environment typically the first to suffer (environmental flows lose competition to household, agriculture, industry water need

14Walter Rast, Director, ICWS, Texas State University & Vice-Chair, ILEC Scientific Committee

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Climate Change Mitigation: Water Quantity• Generally related to control of lake – river interactions

such as floods, droughts (e.g., flood mitigation policy)Water Quality• Eutrophication is typical issue; possible increase in

chemical contamination also suggested (e.g., more investment for nutrient runoff mitigation)

Ecosystem Degradation• Habitat alteration (e.g., creating new protected areas for

fish rearing sites

16Walter Rast, Director, ICWS, Texas State University & Vice-Chair, ILEC Scientific Committee

Walter Rast, Director, ICWS & Vice-Chair, ILEC Scientific Committee 17

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IPCC: Irrespective of scale of mitigation measures, adaptation measures are necessary; emphasis must shift from targeting climate change mitigation to more integrated approach embracing both mitigation & adaptation;

IUCN: Climate Adaptation = Water Adaptation Investments in water security =

Investments in adaptation;

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Water storage in all forms Key role for sustainable development and climate change adaptation; mainly buffer against shortages and excesses decrease vulnerability;

Forms: Dams (reservoirs); aquifer storage and recovery systems; wetlands; ponds/tanks; soil moisture; interbasin water transfers;

BUT storage also has also vulnerabilities to climate change: Increased evaporation; changes in runoff volumes & patterns, etc.

20Walter Rast, Director, ICWS, Texas State University & Vice-Chair, ILEC Scientific Committee

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Climate Change requires reexamination of current approaches in water management, including design of many components of urban settlements and economic and social infrastructure generally;

“Art of Adaptation” in water management is finding right mix of Information, Institutions and Infrastructure;

Information (data): Hydrological monitoring needs highlighted repeatedly since 1977 Mar del Plata Conference, BUT worldwide decline in monitoring of water resources over last three decades; existing databases often outdated (e.g., much GRDC streamflow data more than 30 years old); GEMS/Water in precarious position; many developing world hydrologic monitoring systems deteriorated; even when data available, often reluctance to share with others;

23Walter Rast, Director, ICWS, Texas State University & Vice-Chair, ILEC Scientific Committee

Institutions: Water policies/practices should focus on establishing institutions, information and capacity to predict, plan for and cope with climate variability in order to adapt to long-term climate change; Include institutions providing water for people, industries, energy, agriculture & ecosystems;

Infrastructure: Also relevant to disaster risk management;Hard solutions = dams, ASR, wetlands and ponds as water storage facilities;Soft solutions = demand management, allocations, conservation, water use efficiency, land use planning

24Walter Rast, Director, ICWS, Texas State University & Vice-Chair, ILEC Scientific Committee

Drinking Water Scarcity:• Demand strategies = water allocations between sectors;

reduce water consumption (e.g., improved irrigation techniques); increased public awareness of water scarcity; progressive water tariffs;

• Supply strategies = increasing water availability, including water storage, rainwater harvest, interbasinwater transfer, wastewater reuse, desalination; virtual water

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Extreme Climate Events:• Early warming systems;• Improved physical defense for existing facilities;• Careful site location for new facilities (Japan tsunami)

Sea Level Rise/Flooding:

• Building/strengthening of dikes/embankments;

• Reforestation and coastal vegetation (erosion buffers)

26W alter Rast, Director, ICWS, Texas State University & Vice-Chair, ILEC Scientific Committee

Traditional energy production sources Increased GHG emissions & climate change impacts;

BUT lower carbon fingerprint energy sources also with water environment implications:• Hydropower production river system fragmentation;• Some forms of solar energy require much water, often in

arid environments already experiencing water scarcity;• Desalinization currently requires large quantities of

energy;• Oil shale/sand extraction requires much water, but exist in

water-scarce areas.

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UNEP Experience: Science alone not enough to address sustainable water resources;

Must address water issues in interdisciplinary manner because nature acts in interdisciplinary manner;

As basis for policy-making and planning, integrated water management approach (e.g., IL2BM):• Appropriate policies (“rules of the game”) directed to

sustainable use of water systems; maintenance of ecosystem services;

• Effective, collaborating sustainable institutions to carry out “rules of the game”;

• (Rio Bravo: Water is national responsibility (Mexico) vs. state responsibility (USA); interagency collaboration often a myth) 28

Walter Rast, Director, ICWS, Texas State University & Vice-Chair, ILEC Scientific Committee

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• Stakeholder participation including relevant water resources users & sources; public awareness & understanding of causative/solution roles; difficult in urbanizing world;

• Technology possibilities, including hard & soft options for managing water resources;

• Adequate knowledge & information base, including monitoring needs; use of traditional & indigenous sources;

• Sustainable financial resources to implement & carry out management activities.

Water planning & strategies integrated into broader social, economic and environmental goals;

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31Walter Rast, Director, ICWS, Texas State University & Vice-Chair, ILEC Scientific Committee

Transition to tea-drinking vegetarians!

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