Have you seen a needle dam before? I saw one for the first time over River Reuss. The science of this type of dam is very different from the usual ones. It is not a completely water tight type of a dam, instead it has strips of wood which can be inserted or taken off from horizontal bars across the river. This regulates the flow of water.
When we were at Lucerne, we saw a section of the needles taken off from one side of the dam. Water was gushing out in good speed; it made such a pleasant gurgling sound. The swiftness with which the river was flowing gave a feeling that it can easily sweep off the wooden structure, yet it held on strongly. You can see the covered Kapellbruecke Bridge and beyond that the beautiful Alps (above pics).
This is the view from Spreuerbruecke Bridge. The building with two towers visible in the shot is the Jesuit Church. The onion shaped domes reminded me of the Moghul architecture here in India.