Nature Based Solutions (NbS) are mainstreamed as an innovative and adequate approach to climate change. Combining natural dynamics and materials with technical knowledge, NbS are seen as a promising venue for coastal adaptation. However, little still is known about the role that the many uncertainties associated with such projects play in the effectiveness of these solutions, and about how to cope with these uncertainties, considering the impacts NbS may have for our society. Here, we investigate, if and how, managing uncertainties via the cascades of interrelated uncertainties conceptual framework improves the governance capacity for implementing NbS coastal management projects. To this end, we conduct an ex-post analysis of the uncertainties in two NbS study cases: Sand Engine and Safety Buffer Oyster Dam BwN projects in The Netherlands, critically analyzing through the conceptual framework, how uncertainties were addressed and proposing better fit supporting alternatives. Our results indicate major benefits for uncertainty management, supporting project development and implementation: generating more flexibility in managing under unknown conditions, being able to anticipate conflict, providing opportunities of creating new supporting relationships and alternative solutions.