Additionally, they are using two types. In the riverbed itself they are using larger double gates, while in the higher floodplain (where only the worst peak floods might overflow) they are installing a series of smaller single swing gates. Those in the riverbed seem to deliberately leave gaps for animal migration (no doubt that will be persistently surveilled and alarmed). You can see the two types side by side here:
To the East and West sides of the floodgates, now stand mighty 30 foot bollards. Another major upgrade, is the Patrol road bridge, that will give Border Patrol rapid mobility to both sides of the River, during monsoon flooding.
I have no doubt that this longstanding major corridor for illegal traffic, will also get a large dose of surveillance, sensors and alarms. Infiltrators have long loved to follow the river for the shade, concealment and water, as well as to not get lost.
The patrol road bridge spans are starting to go in now as well:
I am guessing that technology will bristle underneath the bridge, and probably atop light poles as well.