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River

Dams and weirs: 8 Live Cameras — when the gates open

Eight cameras where a river is held back: six in Japan on a gate or a weir, changing the moment water is released, and two in Taiwan on the water stored.

What you can see

A camera at a barrier shows different things depending on whether it looks below it or above it.

The six looking below belong to the Ministry of Land, Infrastructure, Transport and Tourism. Nomura Dam and Nagayasuguchi Dam are seen just downstream; Kanogawa Dam is filmed head-on at the gate the water leaves by. How hard the water is running is readable from the picture, without any numbers. The three weirs are placed on the same logic: Shindenbarai weir is seen from just below, while Hakko weir and Nakaichi weir are filmed from the bank with the structure itself in shot.

The two looking above are in Taiwan. Deji Dam is an arch dam across the Dajia River, and the camera shows its reservoir; Dapu Dam shows the long narrow lake the dam made. These look at stored water, so a change in level turns up directly in how the shore reads. Whether the year was wet or dry can be told from how far up the bank the water reaches.

The eight are put together because they are two sides of the same structure. The Japanese six show only the water going out; the Taiwanese two show only the water held in. Together they cover both halves of what a dam does.

Cameras you can watch now: 8

All 8 are live video. Tap one to open it in the camera list.

When to watch

The six in Japan are most useful during a release and during heavy rain. The picture changes clearly once water starts leaving the gate, so the beginning and the end of a release are both visible. Decisions about evacuating should follow your local authority. These cameras are for seeing what is going on.

The rougher the day, the darker the picture, and rain blurs the lens. Do not expect much of the image.

On calm days the three weirs are the ones to open. The less water there is, the more clearly you can see which way the thread of water spilling over the weir leans.

The two in Taiwan are only one hour behind Japan: noon in Taiwan is 13:00 in Japan, and there is no daylight saving. A lake surface throws light back, so both read bright on a clear day.

The sources do not publish a best season, so this page does not invent one.

If it isn't showing

The sources are the Ministry of Land, Infrastructure, Transport and Tourism (Shikoku and Chugoku regional bureaus) and the Tri-Mountain National Scenic Area Administration in Taiwan. All eight are video, and they are trial streams that can stop without notice. What is happening when a live camera shows nothing explains how to tell why.

Each river is covered in full on its own page: The Hijikawa River (Nomura and Kanogawa), The Naka River (Nagayasuguchi), The Yoshii River System (Shindenbarai), The Takahashi River System (Hakko) and The Oze River (Nakaichi).

The Taiwanese two also appear on Lishan and Emei Lake, Shitoushan. All the river cameras are gathered under River. For another kind of dammed water, the Urabandai pond on Volcanic lakes was blocked by an eruption rather than built.

Where to find Dams and weirs

Agencies publishing the cameras on this page

The footage belongs to each agency. This site is an unofficial guide, and each sample frame was copied once per camera under that agency's terms of use.

To find other cameras, go to the camera list. You can narrow all 439 cameras by format, region, subject and provider.