But the mega dam has long been a source of tension with neighbors Sudan and Egypt. The Grand Ethiopian Renaissance Dam (GERD), 14 years in the making, will be officially inaugurated this week. But for downstream states Egypt and Sudan, the waters of the Blue Nile are vital — and increasingly scarce. Hydropower vs. irrigationOnly a short 15-kilometer (9-mile) drive away from the GERD, Sudan will be the first to feel the effects of the dam — good or bad. "The role of dams may actually become quite important, just like the Aswan Dam manages droughts in Egypt.