Preserving cultural heritage and achieving the Sustainable Development Goal of protecting life below water do not always go hand in hand. The case of the Serpis River sheds light on the political, cultural and legal tensions that may arise when pursuing these two policy goals. To better understand these tensions, we propose acknowledging that rivers are complex natural-cultural systems imagined and shaped through various actors’ values, interests, practices and infrastructures (Boelens et al. 2016). River restoration initiatives generate divisions between actors and institutions with different ways of defining and valuing natural and cultural heritage.