From my understanding through the interviews I collected in Ethiopia in fall 2012, the intention is to fill the reservoir over a period of 5 to 7 years. But this filling is going to take over a huge beautiful, laregly unexplored valley, just east of the Sudanese border. Although an environmental assessment was done of the area, a real ecological investigation has NEVER been done as far as I have found in the records. This area is a transitional zone - from the highlands to the deserts of Sudan. Therefore, given the unique biodiversity in Ethiopia - one of the more amazing things about Ethiopia, along with the human diversity - I would wager there are very unique species living in this valley. Having a relatively low population for eons, human disturbance has been minimal. At night I heard big cats fighting at the river. In the day I saw scores of birds. I really wish some team would get in there and catalogue before it is too late. The environment as a thing in itself, is low in importance for anyone involved in GERD - both the critics and the fans.
Going back through my research I find that the only environmental aspects considered for the dam seem to be water flow, as far as velocity and sediment transport, and silt retention. The environmental discourse needs to expand. I think we should rethink what we mean by environment to include healthy ecosystem functioning...what is going to happen to the species dependent on the Blue Nile's current high and low fluctuations? What will happen to the river banks once there is a release and retention schedule that does not mimic natural flow? What about migratory species of aquatic animals and plants? Maybe even include the dreaded words - sustainable ecosystem services...!