This thesis examines water matters in the Ord catchment. It shows how social, environmental, cultural and economic dynamics are manifest in water matters. In so doing, it critiques material and discursive practices that create environmental injustices, and highlights efforts underway to remedy thoes. The thesis makes two major contributions. First, to dissect water politics in the Ord through the prism of how water matters - from water supply and sanitation, to water allocations for cultural flows. Second, to demonstrate a theoretical means twoards this end, by combining political ecology and environmental justice with a Masseyian spatial approach. Water, as a physical substance, makes tangible invisible power relations. To consider this, the thesis marries political ecology, with its focus on how power and politics help shape human-environment relationships, to environmental justice. A politics of difference informs the particular type of environmental justice drawn on here: it asks whether there is recognition of difference, plurality of participation, and equity in distribution of benefits, in environmental matters (Schlosberg, 2004). This nuanced theoretical terrain blends well with a Masseyian spatial approach that acknowledges places as made of 'loose ends and missing links' (Massey, 2005:12). The latter holds that places are never finished, are always being made, while the former analyses how power relations operate through processes.The thesis presents water matters as contested yet crucial to making sense of social-environmental matters; through contextaulising governance transformations and current water dilemmas, the shape of this contestation becomes clear. This involves spaces of interests coming together, and spaces where interests remain apart. These gaps are renegotiated through instruments such as the Ord Final Agreement. However, fraught water matters do persist, in part due to the complex place-based politics of water in the Ord that include Indigenous politics, environmental contestation, development processes, and a recent colonising history.