Shiromaru Dam fish ladder

Unearthing the Longest Fish Ladder in Japan

On recent nature outing near Okutama I stumbled across non-descript administrative building which just happens to house the longest fish ladder in Japan. The fish ladder is situated along a scenic stretch of the Tamagawa River only 10 minutes’ walk from Hatonosu Station and adjacent to the Shiromaru Dam 白丸ダム. Constructed in 2002 the fish ladder drops some 27 meters over its 330 meters length and appears a somewhat inspiring feat of engineering. Interestingly the cavernous workings are open for public inspection by means of an enormous spiral staircase reaching into its subterranean interior. From here a long passage way carves its way under the dam wall where it is possible to sneak a look at some of the resident fish manoeuvring through the ladder. The fish ladder is open from April through November (free admission) and being located deep underground would no doubt provide some respite in the mist of summer.

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