Interconnected global environmental and societal risks threaten the health of human and ecological communities. Institutions are avenues through which people can mobilize to respond, but institutional landscapes are fragmented. We focus on the need for institutional change in environmental management and water services to better connect land and water in the United States. Using a historical institutionalist approach and insights from sustainability transitions research, we analyze four diverse examples of connecting land and water occurring across public and private institutions where people are putting innovative perspectives and principles into practice: National Environmental Policy Act, Engineering with Natureâ; Water Utilities as Anchor Institutions, and Growing Water Smart. Comparative analysis of these examples focuses on the particular risks these institutions are responding to, how each connects land and water to promote healthy communities, the institutional transformations that are occurring, how problems are being reframed, how leadership and mobilization are driving change, what tools help bridge multiple boundaries, and what new ways of knowing and action strategies are emerging. Our examples focus on transformations within and between institutions in recognition of their importance for driving larger system change. Findings reinforce previous research on the critical role of human agency and boundary spanning in facilitating and steering sustainability transitions.