The plastic fill tubes of the 2.5' AquaDam® are pulled up through the collar and the fill tubes are inserted. Note the coloration of the larger AquaDam®. In contrast to the smaller one, it has a white exterior and black fill tubes.

The weight of the second AquaDam® presses down on the collar from the first and effectively seals them together. Now neither bag can roll laterally.

As with the first AquaDam®, workers must stand behind it to prevent it from unrolling so that pressure will build up and seal it to the riverbed. Even with the pumps on low speed, the rock-picker can barely get them out of the way fast enough.