This slide comparison compares what the Siphandone (Four Thousand Islands area) in southern Laos looked like without the Don Sahong Dam in 2015 and the dam near completion in 2019. The Don Sahong Dam blocked the main channel for fish migration through Siphandone. Migration through the remaining channels of Siphandone are impeded by a collection of Southeast Asia’s largest waterfalls. To mitigate fish migration, the dam developer widened and deepened several other natural channels in Siphandone, but the effects of that mitigation will not be fully known until the dam goes online sometime in the next year.