Inland waters and their biodiversity are a valuable resource. They are a source of fresh water, helping to purify it, and provide habitat for organisms (e.g. fishes) that may be eaten or used by humans. To improve the condition of fresh waters globally, it is imperative to link biodiversity conservation to human well-being. The concept of ecosystem services - the benefits humans derive from ecosystems - offers a means to make this link explicit, resolving the conflict between human water use and biodiversity protection. Ecosystem services thus serve as a proxy for biodiversity, assuming that maintaining the former will serve to protect the latter, representing a win-win conservation solution. While relevant for fisheries (a provisioning service), the substitution may be less applicable to supporting services that depend upon maintaining ecological functioning, not maximizing final services for humans. While valuation of biodiversity (and its subsequent monetization) is problematic, payment for ecosystem (or watershed) services can incentivize land-owners to protect sources of clean water for downstream users.