South on Santa Fe (85) past Hampden (285), Union ave comes up right before (north of) Belview. Park next to the baseball diamonds. Beware the last drop, can be real sticky, but I hear they did some work on it this spring.
I'd recommend letting Union flush for a few days at high flows before getting in the water. This is the first time it's been up like this since last fall and who knows what has built up on the banks
If it stays dry in Denver, Union will probably be in from here through the summer.
Oh, by the way, here's the gage to check for Union:
They change the release frequently, so it's worth checking before you go.