This primer is designed to raise awareness of the multiple benefits of nature-based solutions. solutions most useful to water resources managers (section 3); and adopts the view that: • the first point of resilience to climate change is a well-functioning ecosystem (section 4); • scaling up knowledge and action on nature-based solutions at the local level is most effective through basin water management structures that adopt an integrated approach (section 5); • protecting or restoring environment services in a water catchment reduces or delays the need for future investment in expensive infrastructure in the future; and • water management problems can often be addressed more cost-effectively and sustainably by developing nature-based solutions alone or alongside conventional infrastructural solutions.