The issue that is the most difficult to assign monetary values to the costs and benefits of the flood mitigation strategy is protecting ecosystems.
Ecosystems provide numerous services that are often intangible and difficult to quantify in monetary terms, such as biodiversity, water purification, carbon storage, and recreational value. In contrast, the costs and benefits associated with protecting homes, businesses, infrastructure, and communication systems are generally more straightforward to assess since they often involve direct financial impacts.