Transboundary River Basins: Status and Trends A global, comparative, indicator-based assessment Paul Glennie

Theme 4: Adapting to change … it’s important to know the baseline Additional challenges in a transboundary context

286 transboundary river basins, 151 countries, 2.8 billion people.

9 TWAP River Basins Partners Lead Supporting

THEMATIC GROUPSBaseline Indicators (2010) 1.Environmental water stress 2.Human water stress 3.Agricultural water stress 4.Nutrient pollution 5.Wastewater pollution 6.Wetland disconnectivity 7.Ecosystem impacts from dams 8.Threat to fish 9.Extinction risk 10.Legal framework 11.Hydropolitical tension 12.Enabling environment 13.Economic dependence on water resources 14.Societal wellbeing 15.Exposure to floods and droughts

THEMATIC GROUPSProjected Indicators (2030 & 2050) 1.Environmental water stress 2.Human water stress 3.Nutrient pollution [Environmental water stress] 4.Exacerbating factors to hydropolitical tension 5.Change in population density ‘business-as-usual’ socio-economic scenario (SSP2) and a continued high GHG emission pathway (RCP8.5) WaterGAP & WBM part of IPCC ISI-MIP project (so harmonization undertaken between GHMs).

Lakes  Lake influence Deltas  Relative sea level rise  Wetland ecological threat  Population pressure  Delta governance TWAP has 5 Components at the project level: 1.Transboundary Aquifers (& SIDS) 2.Transboundary Lakes and Reservoirs 3.Transboundary River Basins (RB) 4.Large Marine Ecosystems (LMEs) 5.Open Ocean.

-Comparative assessment = relative risk categories (between basins) -Common relative risk categorization narrative (between indicators) -Guided by science based thresholds where possible. Partners responsible for defining thresholds. Concept of Relative Risk

Key messages & policy implications 1.Risks to basins generally projected to increase … 2.Most of the projected pressures can be managed, e.g. through: demand management, efficiency measures, nutrient man. in agriculture, wastewater treatment, transboundary cooperation. 3.Most issues expected to be addressed under the Sustainable Development Goals (SDGs), 2015 – 2030, but countries have responsibility for reaching targets. 4.Commitment needed to improve guidelines for siting new dams, designing dams for multiple purposes, and optimising operation of dams to maximise human benefits and minimise negative ecosystem impacts and sediment trapping.

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