Controlling Saltwater Intrusion to Environmental Sensitive Areas Due to the Construction of the Rio Anton Ruiz Flood Control Project

The Rio Anton Ruiz Flood Control Project was authorized to reduce flood damages to the coastal communities of Punta Santiago, Verde Mar and Villa Palmira, near Humacao, Puerto Rico. Flood damages used to impact those communities throughout the year until the authorized flood control project was built. Historically, flooding occurred when runoff from the mountains within the watershed would flow into a large upland lagoon and then flooded those communities before reaching the Caribbean Sea. The authorized flood control project protected those communities from flooding by the lagoon with a large levee system and a series of canals to the sea. Since the completion of the authorized flood control project in 2001 there have been major impacts to the lagoon and a surrounding environment due to salt water intrusion. Some of the primary impacts have affected Humacao Wildlife Refuge, which has the last major remnant Pterocarpus Forest on the Island of Puerto Rico. That species of tree is endangered and has a low saltwater tolerance, thus requires mainly freshwater to survive. The lagoon has some fish and other plant species such as mangroves that rely on both fresh and saltwater. Therefore, a series of saltwater intrusion measures were developed and constructed to limit the amounts of saltwater that impact the lagoon and the Pterocarpus Forest as a result of the some of the constructed features from the authorized flood control project. This paper will show how the flood control project was developed, illustrate the some of the project oversights and project dynamics that caused the saltwater intrusion problem, and then explain how saltwater intrusion measures were developed with unique construction measures that were required for installation in environmentally sensitive areas.