Don't You Hate It When That Happens!
TVA has Columbia Dam. The USBR has Anchor Dam. This dam, located on the south fork of Owl Creek near Thermopolis, Wyoming, was started in 1957, and the primary structure was completed in 1960. Its official status is still "under construction", although they have pretty much given up. When the reservoir started filling, sinkholes started forming from the weight of the water that completely drained the reservior. They have tried "plugging the drain", so to speak, but new holes just keep opening up. They built a couple of dykes upstream to try to store a little of those was breached by a flood, so they rebuilt it with a spillway that has been used once or twice.
The maximum reservior level was supposed to be 6,451 feet MSL, where the spillway would start spilling. They think it got to its highest point at 6,418.5 in 1967. But it's not a total loss. Although the irrigation supply is severely limited, the flood storage capacity is pretty dramatic!