**Abstract**

In the state of Ceará, northeast Brazil, in the 1950s, an industrial harbor was built. The harbor structures and other factors, such as the destruction of the bypass of dunes, produced a large erosive process downstream, responsible for the loss of 400 m of beach in six decades. In Canoa Quebrada beach—an internationally famous tourist area—recently, the partial collapse of sea cliffs occurred because of inappropriate uses and occupations, causing landscape and economic damage. In Colombia, beaches are under an intense process of erosion, due to construction for housing and tourism. With the abrasive action of waves associated with rising sea level, coastal areas in both countries are under risk of major degradation. These environmental situations are the object of technical and scientific analysis and discussion in this chapter, and mitigation propositions are considered.

**Keywords:** Northeast Brazilian coast, northern Colombian coast, coastal erosion, coastal mitigation
