The construction of the 500,000m3 dam enables dewatering of the mine pit, which is now underway, said the company.
Once water levels are reduced - the dam is receiving water from the mine pit at a rate of 2,500m3 per hour - the company will be in a position to safely regain access to high-grade ore areas.
"After an arduous process we are delighted to have completed construction of the 500,000m3 dam at La Parrilla enabling us to proceed with the full scale dewatering of the mine pit," said chairman Michael Masterman.
"This is a major milestone and importantly will lift the constraint to our mining operations enabling us to accelerate the process of regaining access to and recovery of the higher-grade ore."
In May, W Resources completed a plant improvement programme at La Parrilla that resulted in a 60% recovery rate for tungsten despite engineering setbacks caused by the rainfall in the region.
La Parilla has an Australasian Joint Ore Reserves Committee compliant resources total 49 million tonnes at a grade of 998 parts per million tungsten trioxide. and JORC compliant reserves of 29.8mt at a diluted grade of 931ppm WO3.
