Flooding the Grand Canyon

Tears came to my eyes as I read about the water from the dam being released into the Grand Canyon, in order to create silt to try to stop the extinction of native fish and plants. How sad that placing the dam there has altered the eco-system permanently, already making some fish extinct and reducing the native plant population. How could we have made such a short-term decision, impacting such a magnificent natural wonder?
I visited the Grand Canyon twice, and did not expect to be overwhelmed by it. I ventured part way down on a donkey trip, but had to stop due to memories of two previous (and not pleasant) donkey journeys. The one on the island of Patmos, Greece, ended in a fall, with me and my donkey rolling all the way down a mountain. The trip in Petra, Jordan, ended up with me leading the donkey, as the owner rode down. I admit the treacherous journey down was worth it, as Petra had just recently been re-excavated and was truly a jewel as described.
I guess, since I majored in an independent study major entitled "Environmental Politics" in 1973, I know the answer to why the dam was built, despite long-term environmental impact. And it makes me sad. I will look forward to the studies and reports from the scientists that research the benefits of the water and sediment release, and hope, perhaps, that a few more releases of water could reverse the erosion.