The $495 million dam, which China Huandian Corporation will control, is expect to produce 338 megawatts by 2015.
The Xayaburi dam is planned in Laos’ northwestern Xayaburi Province, more than 1,000 kilometers upstream from Phnom Penh.
Agriculture contributes more than 30 percent to the GDP and is valued at around $10 billion per year.
Cambodia has an estimated 25 different mineral types, from bauxite to zinc, gold, iron, and gems.
Thailand is the world's largest rice exporter, followed by Vietnam, and Cambodia meanwhile exports about 100,000 tons per year.
Agriculture has emerged as a main economic driver for Cambodia, propping up the country in the wake of the 2008 financial crisis.
A total of four people have died in storms and flooding since Sunday.
Heavy rains on Monday flooded the homes of at least 1,000 people in the Boeung Kak lake area of Phnom Penh.
Local authorities are still assessing the damage from Sunday's storm, which may have destroyed some homes.
Lack of information about proposed Sambor hydro dam across the Mekong in Kratie raises concerns for locals.
The high cost of the systems mean they are generally installed for the well-off, in places like new villas.