Union

Fun local run from the Rt. 1A bridge down to the Pump House. There's a spot to pull off on the right of the road as your're heading towards Bangor, just on the Ellsworth side of the bridge (right next to the old rail tracks). If you walk across the tracks you'll see a small trail down to a pool that can be used as a put in. From there, either go down the bridge rapid or paddle upstream to a smaller rapid around the corner. Maybe 3-4 smaller drops after the bridge rapid, and then you can pull around to the ramp by the pump house cove described below. Shuttle is an easy walk up Shore Rd. Note that the pump house itself is private property, so you have to bring your boat all the way into the cove to take out.

Gauge for the Union River from Graham Lake Dam to Ellsworth:

https://www.safewaters.com/river-system/15

Lovely little Class II in-town run, with a walkable shuttle. A couple nice surf spots at most levels.
Put-in at the SE corner of the Rt. 1A Bridge, and paddle upstream a couple hundred yards for the first small rapid to warm up a bit. (At levels above ~4000cfs this is almost completely non-existent.)

As the river goes under the bridge, it enters a longer rapid, with a few wave trains, good eddies on both sides, and at some levels, a hole worth keeping an eye on right in the center, near the top of the rapid.

At the end of the rapid you'll find a surfing wave just to the right of a low rock with two bushes on it.

Next the river divides around an island with a half-dozen trees on it and rejoins for a short section of Class II.

A couple other minor features after that. Take out along the Shore Rd, or a little further down at Pump House Point, where there is a hand-carry ramp and parking for 3 cars. (Watch for poison ivy along the shore rd. In summer the Pump House is a safer bet.)