Groundwater storage An important key to tackling climate change to ensure safe drinking water and sanitation lies in the great inertia and relative stability of groundwater, stored in aquifers. Aquifers are nature's water lungs, storing and protecting huge quantities of water underground, under fairly and more stable conditions than surface water bodies. Depending on how they are managed, the water levels and quality of aquifers can and should be as strategic drinking water reservoirs for managing future droughts. Impacts on the human rights to safe drinking water and sanitation Over-pumping can deplete the aquifers breaking their vital function as strategic reserves for droughts, and can lead to declines in water quality through by increasing the concentration of pollutants and/or favouring saline intrusions in coastal aquifers. The exploitation of deeper groundwater sources also has implications for affordability of water and sanitation services, as pumping costs can increase tariffs making them unaffordable for the most impoverished. The exploitation of deeper groundwater may be a short-term alternative but it has no prospects for sustainability and may have implications for the affordability of water and sanitation services, especially if water markets are in place, enabling speculative businesses based on people´s most basic need, including their human rights to safe drinking water and sanitation. Wetlands, riparian ecosystems and vegetation cover Strengthening the resilience of aquatic ecosystems is one of the keys to climate change adaptation strategies, and to this end it is essential to recover and conserve, not only of aquifers, but also of the most inertial surface water ecosystems: wetlands and riparian river ecosystems. Wetlands are surface water reserves, which regulate river flows. They expand river floods and soften their destructive energy, while, on the coasts, mangroves protect coastlines from major storms. They are natural macro-purifiers that regenerate water quality, prevent eutrophication processes and sustain a large part of the biodiversity on continents and coasts. On the other hand, we must be aware of the importance and functions of riverside ecosystems and riparian forests, as part of river channels. Even the vegetation cover of islands and continents is key in protecting the water cycle from the impacts of climate change, since they prevent soil erosion and favour infiltration into aquifers. Impacts on the human rights to safe drinking water and sanitation Ecosystem collapse will lead to widespread declines in water quality. The destruction or degradation of vegetation cover facilitates soil erosion, thus increasing the sediment load of water, accelerating the clogging of reservoirs and reducing infiltration and recharge of aquifers. Restoring and maintaining the good condition of aquatic ecosystems and vegetation cover increases drought buffers and regenerates water quality, while smoothing floods, in the most effective and economical way. Ultimately, it reduces risks to the population, especially the most vulnerable and impoverished, while protecting their human rights. 7