The Leaders’ Pledge for Nature highlights the fact that since ecosystems underpin human well-being, we need to “recognize that the business case for biodiversity is compelling”. In this article we argue that, in all areas of water management, there is an urgent need for a paradigmatic and practical shift to species-inclusive and sustainable water policies and practices. We believe that policies prioritizing human interests inevitably promote unsustainable forms of water management and use. This article outlines an alternative vision based on the “Half-Earth” (Wilson 2016) perspective, emerging from the “nature needs half” or NNH movement. NNH researchers state that to maintain viable long-term populations of most of the Earth's remaining species, approximately 50% of landscapes and seascapes need to be protected from intensive human economic use. However, while terrestriaconservation measures are prominent in the literature, a Half-Earth, of fresh and sea waterscapes is rarely discussed. Our article addresses this omissionWe ask what species-inclusive policies and practices in marine and freshwater conservation would look like? If government policy-makers direct spending towards sustainable fishing, for example, how can this align with a focus on marine biodiversity? How can an ecocentric view tackle the illicit finance involved in illegal fishing? How do we marry up existing conservation policywhich is people-centric, with ecocentric 'nature positivity'? We reflect on possible implications for ecocentric water management and sustainable water policies and practices from examples of non-governmental organizations (NGOs) Sea Shepherd and Greenpeace. We also note the potential for Strang’s proposed ‘re-imagined communities’ approach to be applied to river catchmenand marine management, providing a conceptual model for rebalancing wider decision-making processes to include non-human needs and interests.