One issue with putting a dam on the Bear River that hasn’t been brought up yet is the potential impact pollutants have the aquatic ecosystems of the river itself and the Great Salt Lake. According to “Bear River” by Craig Denton, because of irrigation the water from Bear River already contains “fertilizers (nitrogen and phosphorus), herbicides, and pesticides.” Eutrophication in the Great Salt Lake thus far has been avoided because the summer release of these irrigation waters carries otherwise dry sediment river bank sediment into the river. Riparian habitats are damaged because the water is too dirty to support plants and microinvertebrates alike (Denton). The net effect is a reduction in biodiversity. It also leads to sediment buildup in the Great Salt Lake itself–and as has been mentioned, exposure of such sediments poses a public health hazard. Increased use of water for agriculture would increase the buildup of fertilizers and pesticides, which could create a problem akin to the current one in the Jordan River without expensive treatment. Building a dam in the first place would cost one billion dollars (http://le.utah.gov/audit/15_01rpt.pdf), and maintaining it and the riparian ecosystems would be even more costly. Developing the Bear River in this manner seems likely to cause more trouble than it alleviates, especially in light of externalities like ecosystem function.
