The Tiu Kulit Dam Project will provide reliable irrigation to 1700 hectares in Sumbawa District of NTB Province by constructing a dam on the intermittent Tiu Kulit River. Experts from Indonesia and the United States have reviewed the project plans and concluded that it will accomplish its primary objectives, but that significant environmental effects might result. This environmental assessment, prepared under the laws of Indonesia and the United States, explores the potential effects of the project on human and natural resources and recommends actions to mitigate adverse effects and enhance benefits.