Cochilco said part of the fall was due to a 1% reduction in the quantity of mineral processed as well as miners moving to use more seawater and to recirculate water more.

The agency said seawater use increased by 1.7% to 4.06cu.m/s and recirculated water by 15% to 53.32cu.m/s, with a national recirculation rate of 76% compared with 73% in 2018.

Seawater now provides some 25% of the water used by mining with 1.84cu.m/s used directly in processes while 2.22cu.m/s is desalinated seawater. The majority is consumed by copper mines in northern Chile.