Philippines Groundwater Outlook (PhiGO)

Half of the world's cities with populations above 100,000 are located within water basins where over half of the available water supply is depleted for part of the year. These water-stressed cities are finding it extremely difficult and expensive to secure the additional water supplies needed to support their growth. Water security is of particular concern for Filipino cities, which have been designated amongst the worst in Asia for urban water security. Changing climate and increasing urban population density will put more stress on their water resources. Current projections of climate up to 2050 suggest the Philippines will become warmer, with increasing temperature and decreasing rainfall during the dry season and more extreme rainfall events during the wet season. This will undoubtedly exacerbate both water availability during periods of drought and the magnitude of flood events during periods of heavy rainfall. This susceptibility has led to the Philippines being consistently ranked near the top of countries most at risk to climate change. In addition to water stresses from a changing climate, population is expected to increase by ~50% up to 2050, with urban population set to double over the same period. This will further exacerbate pressures on future water resources.

The influence of climate and population change will have an acute impact on groundwater, which currently supplies more than 50% of the potable water supply and 85% of the piped water supply in the Philippines. Groundwater is strategically and economically important to current and future water supply and is the principle source of dry season river flows, which in turn are often used for potable supply. Despite the high reliance on groundwater resources, reasonable coverage of groundwater datasets and several regional-level groundwater management plans, there has been little in the way of real-time monitoring, routine monthly forecasting or impact assessment of climate and population stressors. Through a programme of data gathering, knowledge exchange, fieldwork, numerical modelling and stakeholder engagement the Philippines Groundwater Outlook (PhiGO) project seeks to undertake assessments of population and climate change impacts on regional groundwater resources and translate these into usable forecasts of flood and drought risk. There are two distinct timeframes at which uptake and potential benefits of the project will be realised. Short term, seasonal-scale forecasts will aid in reactive preparedness, whilst long term, decadal-scale forecasts can be used to take proactive steps towards reducing the future physical and economic impacts of extreme hydrometeorological events. To better understand the potential socio-economic impacts of groundwater level extremes and potential water management strategies, PhiGO is also focussed on quantifying the cascading impacts of flood and drought through key infrastructure and analysing the cost-benefit of differing water management and urban planning scenarios.

The overarching goal of the project is to deliver consistent, accessible and transferable assessments of climate and population change on regional groundwater resources and to assess the subsequent influence on flood and drought risk, and socio-economics. Key to delivering economic and societal impact is improved communication and collaboration between stakeholders across the local community/actor-management-policy scales. This proposal addresses this by formalising engagement between the relevant stakeholders. We will disseminate research findings widely, seeking to maximise the use of the new knowledge generated within Filipino policy and planning frameworks, and to remove barriers in the effective deployment of risk forecasting by working with government, local authorities, businesses and local communities to co-design dissemination routes and methods.

The project builds on the recently established regional groundwater management plans in the Philippines and will contribute to a number of local water management issues identified for Iloilo City and Pampanga regions. This research will provide a comprehensive, transferable framework for forecasting seasonal and decadal-scale groundwater induced flood and drought risk. The proposed work is designed to address key data and knowledge gaps that influence many of the practical solutions available to flood and drought risk influenced decision-makers. Regional needs are addressed directly through improved seasonal flood and drought risk forecasting systems and detailed quantitative analysis of population and climate change impacts of groundwater resources for the two case-study areas. The opportunity to meet national needs and those of the international community will be delivered through the outputs developed in the project, which will be of particular relevance to water managers and urban planners.

To ensure maximum stakeholder engagement, we have created a tailor-made workshop programme for stakeholders. We will also create web-based platforms designed to act as a hubs for best practice documents, literature, field data, simulation output, analysis. These platforms will be designed to be readily transferable to other water critical regions in the Philippines. They will also be a valuable resource for similar initiatives in other water-critical regions of southeast Asia.