Climate change is impacting a wide range of sectors, with water being one of them. Even though, over 2 billion people live in countries that are already experiencing high water stress , by 2050 around 52 % of the world’s population is projected to live in water-stressed regions . Climate change is projected to reduce renewable surface water and groundwater resources significantly in most dry subtropical regions and negatively impact freshwater ecosystems by changing streamflow and water quality . Water stress is not the only challenge brought on by climate change. By 2030, the number of people impacted by floods might double worldwide , causing damage to urban water systems. At the same time, water and wastewater utilities contribute to global greenhouse gas emissions, with emissions coming especially from energy consumption (often by burning fossil fuels), wastewater collection, wastewater treatment, wastewater discharge and sludge management.
Scientific evidence is now pointing at the impacts of climate change on water utilities worldwide. A 10 years scientific study in Norway suggests that extreme weather events contribute to poor raw water quality . Also, impacts in wastewater utilities in countries like New Zealand have been reported to fit in 3 categories: Nuisance flooding spills and odor, water quality deterioration and damage to infrastructure . Climate change will affect water resources generally through increasing temperatures, sea-level rise, shift in the precipitation patterns, changes in snow cover, and the increase in the frequency and intensity of flooding and droughts, which might cause a shortage in urban water supplies and damage to infrastructures .These hazards occur with different intensities depending on regional and local variables, which is why urban water utilities need to assess climate risks individually.
A climate risk assessment is the first step for resilient water management, which is a prerequisite for successful climate change adaptation. Once water and wastewater utilities have identified and prioritized their most critical climate risks and critical thresholds, adaptation actions can be implemented to confront climate change impacts. Examples of these measures include: Building traditional or nature-based flood barriers to protect infrastructure, diversifying water supply, wastewater reuse, improving water storage, identifying and repairing water leaks, relocating facilities to higher elevations, among others . International donors and funding mechanisms provide climate funding for adaptation measures. These include among others the Global Environmental Facility, the Adaptation Fund and the Green Climate Fund. At the same time, other financial mechanisms such as taxes and subsidies could contribute to financing adaptation measures in urban water utilities.
Climate Risk Management in Indonesia. Photo Credits: GIZ
Restoring and managing natural and artificial ecosystems and water storage systems sustainably could be our best ally for climate adaptation in the water sector. Groundwater aquifers, if sustainably managed, can store excess water and guarantee water provision in times of drought. Jordan for instance, is highly dependent on groundwater resources and faces increasing water demand. This has led to reduced groundwater availability, the salinization of groundwater resources and the collapse of biodiverse natural water reserves such as the Azraq wetland reserve. More than 80% of Jordan is unpopulated due to desert conditions, where annual precipitation falls under 50 millimeters, and yet the country is projected to become drier under climate change . Therefore, in order to safeguard the strategic function of groundwater aquifers for the urban water sector in times of overexploitation, these must be conserved through sustainable water withdrawals and aquifer recharge practices.
Qunli Stormwater Wetland Park in China. Photo credits: Turenscape
Moreover, adaptation measures could include Nature-based Solutions (NbS) which involve protecting, restoring or sustainably managing natural or modified ecosystems to improve resilient water and wastewater management. Common NbS for enhancing raw water availability, quality and protect infrastructure from flooding include among other activities basin and mangrove reforestation, aquifer recharge, urban lagoons, rainwater capture and artificial wetlands. Nature-based Solutions have the potential to address climate resilience challenges while bringing additional multiple benefits such as clean water, clean air, climate regulation, biodiversity, food and water security.
Finally, it is necessary to switch from a response-based action to an anticipatory climate risk planning to avoid reaching critical thresholds where impacts are intolerable. As water and climate change do not have borders and a single actor cannot effectively address complex water issues, cross-sectorial cooperation and a participatory approach are key for climate resilience.
We all depend on a reliable supply of clean drinking water and efficient wastewater systems to sustain our health. Therefore, water and wastewater utilities are key agents and need to ensure business continuity through considering climate risks in their strategic planning, operations and cross-sectorial initiatives.