Update. I walked along Benner Springs this afternoon. Here are photos of what they did. They installed structures on the opposite bank from the park area, a good distance. The first phase placed structures on the parking lots side of the bank. The new configuration greatly narrowed the channel and already you can see the clearing of the grass and sediment from the center. The stream is deeper and they also placed some decent sized rocks to provide cover in the stream.
If they continue down to the wide area below the island, this will significantly improve the stream IMO. Those flat areas make the Benner springs section the warmest on spring creek.