Jul 24, 2012

Shiromaru Dam Fish Pass--a nice summer resort

A fish pass is a construction built at a dam so that fish can swim upstream or downstream through it.

On a recent Saturday, I visited Shiromaru Dam Fish Pass. This is one of the Japan's largest fish passes, with the vertical interval of 27 meters and the allover length of about 330 meters. On the downstream side, the fish pass lies on the surface of the earth. However, as the fish pass goes upstream, it halfway goes into a tunnel underground.

When fish swim upstream along the fish pass, they first swim up in the part that is build as a series of close-spaced baffles placed along a long slope (I think this is something called a baffle fishway). Water flows through the space between the channel walls and each baffle. Each baffle of this structure slows down the water flow providing resting places for fish. Then, fish get in the tunnel and reach a relatively big pool. This pool provides a resting area for fish, and I saw trout swimming in the pool before although I didn't find any fish here this time. After leaving the pool, fish continue swimming upstream through another part which consists of a series of partition walls. Each of the walls has holes in the lower part of them so that fish can go through the holes.

(Baffle fishway part

(Partitioned part

By the way, visitors to this fish pass can go down underground through a big vertical shaft to see the underground part of the fish pass. A spiral staircase along the inside wall of the shaft leads you to the bottom of the hole, where you can easily come to the pool built in the middle point of the fish pass. You can also walk on the passage along the fish way.

I parked the car in the parking lot in front of the janitor building of the fish pass, and then enter the building, in which a janitor booth was found. Sometimes, there is someone in the booth, and sometimes there isn't. Anyway, visitors can see the fish pass free of charge. Inside the building, the big shaft was wide open, waiting visitors to come in.

Visitors circle down along the spiral staircase inside the big vertical hole. This hole seemed very deep. How deep is this hole? The vertical interval of this fish pass is 27 meters, which must be the difference between the water level at the entrance on the downstream side and the water level of the upstream Shiromaru Dam. I felt the hole was over 30 meters deep. Since the janitor building is placed at a place that is quite higher than the dam water level, I think my guess is not an exaggeration. Going down deep underground seemed somewhat thrilling.

Because of such a deep vertical hole, it is of course very cool inside even in midsummer. Shiromaru Dam Fish Pass is a nice place to visit on a sizzling day.

Today's Sake
Shiroyama-zakura and Sawane (しろやま桜 and さわ音)
Recently, I purchased Kisho Junmai-ginjo Namazake Shiroyama-zakura (喜正 純米吟醸 生酒 しろやま桜) and Sawanoi Junmai Namzake Sawane (澤乃井 純米生酒 さわ音) at a nearby liquor shop. I took the photo below long before, and it seems that this time I also purchased these bottles of Shiroyama-zakura and Sawane together. This means that I love the bold taste of Shiroyama-zakura while I want some airy refreshing factor like one Sawane exhibits in summer time?

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