Geograph - photograph every grid square

I'm not certain what purpose this platform in the Afon Rheidol serves. It is located just upstream of the turbine house of the Rheidol hydro-electric power station, which is fed by water collected higher up the Rheidol (at Dinas reservoir) through a pipeline. My best guess is that it is a river level and flow gauge monitoring the water coming down the natural course of the river in order to adjust the discharge from the reservoir and the power station. However, this doesn't explain the purpose of the two hoses entering the structure on the right.