Sustainable water management in Southern Ecuador: water availability under climate change and adaptation strategies.

Anthropogenic climate change together with non-climate drivers (e.g land use change) have affected natural and human systems in the Andean Mountain region. There is more evidence of changes in water systems, with decreasing water availability and increasing frequency and magnitude of extreme events (i.e. flooding and droughts). This region is especially vulnerable to climate change and faces challenges towards adaptation due to limited resources and policies. Therefore, we present an integrated water management (IWM) approach to secure water availability in a middle-size city in Southern Ecuador - Cuenca. The Andean city of Cuenca (~ 600 000 inhabitants, located at 2600 m a.s.l.) depends highly on precipitation and surface water from the highlands to ensure drinking water. Due to its complex orography, climate change projections are not yet available at an adequate resolution for local decision making and limited actions and plans towards adaptation are undertaken. Our IWM approach, then, involves two phases: (1) Quantifying water availability projections. Statistical and dynamical downscaling techniques are used to quantify climate change projections at 1 km resolution for the study area, together with indicators useful for decision-makers. Discharge projections are quantified by using conceptual and distributed hydrological models. In parallel, water consumption is monitored and projected. Finally, we find water availability projections towards 2100. (2) Constructing adaptation strategies. On the provision side, water management improvements are co-constructed with the local drinking water company (ETAPA EP), such as: evaluating old infrastructure (e.g. leaks control), proposing new green-blue and gray infrastructure. On the demand side, strategies to reduce water consumption are co-constructed and implemented within a pilot project that involves citizens from three neighbourhoods in Cuenca. Our study involves a variety of actors and sectors (i.e. Ecuadorian and Belgian Universities, decision- and policy makers and citizens), enhancing capacity building of local governments and transferring knowledge among Universities and institutions, to plan and implement adaptation strategies through bottom-up approaches. We expect that our approach can be used in other middle-size cities, with similar challenges or complex orography conditions.