I stopped at the Santa Cruz River on my way home today. There's a place on Ina Rd that's good if you only have a few minutes, on the east side. From here you can look north down into the riverbed. If you have more time you can explore the south side.
Here's an aerial picture for reference; red is on the north side; blue is where I park to bird the south.
There is space enough for a few cars to park:
And here's the view:
Closer inspection (a scope is handy) reveals lots of Black-necked Stilts...
Here's a partial list of what I saw today:
10 American Wigeon
10 Cinnamon Teal
40 Northern Shoveler
20 Green-winged Teal
196 Black-necked Stilt
7 American Avocet
1 Spotted Sandpiper
20 Least Sandpiper
23 Long-billed Dowitcher
Waterfowl numbers and species are down from earlier in the year; the stilts and dowitchers have been there through the winter. There's a lot of construction on the west side bank; it is part of Marana's work on the new park at Silverbell and Cortaro.