In March 2004, the dam and Balgo and Morotsuka villages have been included in the List of Japan’s Registered Tangible Cultural Properties (Buildings).

[5] The Kyushu Electric Power Co., Inc. has assured that "it will maintain dam as a tourist resource and educational tool in cooperation with local governments.

An unusually high annual precipitation of 1000 mm has been recorded in recent years in the Kyushu region and assigned to climate change.

This process created extensive cultivation of Peridinium bipes of dinoflagellate, which generated a foul smell and discolored the water surface area thus marring the scenic beauty of the reservoir.

With the automated process operated from the ship, the red tides are eliminated almost completely using ultraviolet (UV) irradiation.

A nephelometer installed at the treatment facility provides feedback on the bloom density for adjustment of exposure time to UV radiation.

The entire process takes about 5 hours and a success rate of 99% removal of the algae is reported, killing all cells over an initial treatment of two days.