Using the same recycled HDPE tub inserts employed with modular planters, Utilihab supports the use of integral ponds. These can be used simply as a decorative feature but also serve such functions as reflecting ponds along building windows to increase sunlight penetration and for greywater filtering marshes. Ponds can be set in the usual raised planter box frames or set into the deck surface with the tub extending below the raised deck surface. In most cases the tubs can be set atop a gravel bed under the deck to support its weight. Higher decks, however, must use a profile suspension frame that attaches to the underside of the deck framing grid and surrounds the tub to support its weight. In some cases the space around the tubs may use some form of insulation or surface-mount electric cable heaters. The profile deck framing makes for easy integration of pumps and plumbing and, combined with the modular planter system, elaborate multi-level water gardens, fountains, and waterfalls can be quickly created using a few different pond container shapes.

Hot tubs and small swimming pools can also be created in the same fashion as these modular ponds, though this requires the use of larger and deeper HDPE container inserts. Some off-the-shelf hot tub shells may be sized to fit within the deck grid or raised planter box framing. Horse tanks, industrial poly tanks, and other such items can also be adapted to this purpose. Since the Utilihab pergola and gazebo structures are also based on the same deck grid, it becomes possible to easily combine these to create enclosures for pools an hot tubs.