Once the collar is unrolled, two holes are cut in the top of it. The fill tubes of the second AquaDam® are pulled up through the holes and the first 15' of the second AquaDam® is slid into the attachment collar extending off the closed end of the first AquaDam®.  

This creates a 4' high bank which keeps the fill tubes high enough to properly inflate the second AquaDam®. The discharge hoses are inserted into the fill tubes that extend up through the attachment collar. Water is pumped in causing the AquaDam® to unroll.

The unrolling must be controlled by workers standing behind the rolled portion of the AquaDam®. This is a very low-flow diversion, but a head difference of even an inch must be kept in check and compensated for. You can see the attachment collar extending off the end. 

Notice how deep the water is now compared to the earlier pictures. Notice also the coupling of the two AquaDams® in the middle of the picture.