Opinion: Glen Canyon Dam has created a world of mud
When the San Juan River flows out of the San Juan Mountains in Southwestern Colorado, it contributes 15% of Lake Powell’s water. But there’s a problem: The river carries a hefty 55% of the sediment entering the reservoir, and that mud is piling up. … Now, as the San Juan River flows toward Lake Powell, it rambles over a huge pancake of mud that’s 49 miles long, a mile wide in some places, and as much as 120 feet deep in the final reaches of the San Juan River. Unique hydrology has contributed to this plug, a relatively wide canyon and multiple waterfalls slow down the river, allowing sediment to drop out. Though the San Juan is the muddiest tributary, all the Colorado’s tributaries drop a good deal of mud 100 miles or more upstream of Glen Canyon Dam. It’s a Western phenomenon caused by damming swift rivers …
-By Dave Marston, publisher of the independent nonprofit Writers on the Range.