The US$16mn project will help protect a flood-prone town in the Argentine province.
The company reported higher revenues and lower debt service costs.
Torrential rains sparked by the La Niña phenomenon has destroyed roads, homes and cropfields in at least nine departments in Bolivia.
The works to rehabilitate and expand the largest facility of its kind in El Salvador will be the responsibility of French water solutions firm Suez.
Construction works will be carried out by a Spanish consortium comprised of FCC Aqualia and Aqualia Intech.
Aguas Chañar, which provides service to 91,000 residents in northern Atacama region, is being targeted by Aguas Nuevas holding company.
Mayor Miguel Ángel Mancera claims the authorities have detected 50 locations where water valves are being manipulated for political gains.