08/06/2026
The pit filling process has begun!
After a successful decommissioning phase that involved removing equipment from the underground and open pit mines, siphons were activated at Diavik’s A21, A418, and A154 mines over the last several weeks.
Pit filling is expected to take approximately 6 to 12 months. The rate of filling will depend on water levels in Lac de Gras, with controls put in place to ensure that the process has minimal impact on the surrounding lake and downstream river. Fish screens (which can be seen in the third photo) have been installed over the siphons to ensure the safety of local wildlife.
Once filling is complete, Diavik staff, community members and regulators will monitor water quality in the pits. Once the water quality is deemed to meet acceptable criteria, the pits, which were situated beneath the lake prior to mining activity, will then be reconnected to Lac de Gras.
The filling of Diavik’s mine pits is central to its approved Final Closure and Reclamation Plan. We remain on schedule to complete active closure activities at the Diavik site by 2030.
