In all future projects, people are required to think and respond to the following question: what should be the relationship between nature and humans? This question is necessary because global warming is rapidly increasing and the threat to environmental issues is close to our daily-life. In recent years, one of the most certain outcomes of global warming is an increase in global sea level. Researchers have found that this issue causes economic, environmental, and political problems. Consequently, if the sea level rises, the local government along the coastal line is threatened with losing the strong tourism and tax revenues. In addition, by understanding the coastal erosion itself and analyzing the data of expected of coastal eroded area on beach communities, by using Geographic Information System (GIS), private property owners and public institutions face the threat of losing their land and to risk a serious natural disaster. This study contributes to avoid this tragic situation and to create sustainable beaches. The “Multi-Purpose Artificial Reef” is one of the very effective and sustainable solutions, to redevelop beaches both environmentally and economically. This study examines how the multi-purpose artificial reef works for the threatened coastline, in order to manage a better coastal line. Also, this study contributes to the argument that the project of developing coastline, affected by coastal erosion, has really a significant roll for California government and citizens. Therefore, the result will be shared with the California government, developers, and planners who set policies and conduct projects in the coastline, in the future.