As the founder of Water Foundry and now the Practice Leader for Water and Nature at Earth Finance, William Sarni bridges high-level strategy with on-the-ground execution—developing and implementing transformative water and nature strategies for industries ranging from consumer goods to manufacturing and tech. He leads ventures, advises startups, and designs market-entry strategies that push the boundaries of how water, nature and climate resilience is built inside the enterprise.

His career spans over two decades of founding companies, directing global consulting practices, and guiding multi-stakeholder initiatives, including prize competitions, tech accelerators, and public-private coalitions. From boardrooms to basins, Sarni’s work shapes how capital, innovation, and ecosystems intersect—and how companies move from compliance to real, measurable impact and create business value.