Celebrating World Water Day 2021 on March 22nd, six experts, backed by five organizations (Stockholm Environment Institute, GIZ, Viva con Agua, WaterWorX and EXP-Consult) present a plea for greater and wider collaboration to shape the water sector to become more climate resilient. Improved management of water and sanitation services is fundamental not only for climate change adaptation but also for mitigation – and collaboration plays a major role in this. The report published under the umbrella of SuSanA describes important guidelines as well as specific approaches and regulatory framework conditions for cross-sectoral collaboration, as well as case studies from around the world. Low-carbon and climate-resilient water and sanitation services are technically feasible and economically viable. Cross-sectoral collaboration is needed, but must be done proportionately, with due consideration of opportunities and risks. With an appropriate regulatory framework in place, this can add important value for the implementation of SDGs and the Paris Agreement.