Complex sentence: The Instituto Costarricense de Electricidad suggested in 1996 the possibility of building a hydroelectric dam on the river, this plan was finally rejected in 2005 due to concerns about the pollution and other impacts on tourism and the ecology of the river and its surroundings.
Split into simpler sentences: The Instituto Costarricense de Electricidad suggested in 1996 the possibility of building a hydroelectric dam on the river. This plan was finally rejected in 2005 due to concerns about the pollution and other impacts on tourism and the ecology of the river and its surroundings.