Coanda Screen

A boring work picture with a technical title. A Coanda screen is a cleverly designed mesh filter spanning a concrete intake channel. The water decants across the downstream face of the screen thus creating a self cleansing effect. Other designs, where the intake is presented towards the flow, are prone to clogging with debris and require considerable maintenance.
The whole point of this structure is to abstract water at height (head) on a hillside, allow it to settle in a large chamber adjacent so that air bubbles  are removed (thus increasing the density of the water (mass) before it continues down hill in a pressurised pipe line, called penstock, to a turbine powered generator.
The energy you get is the mass times the head times an efficiecy coefficient. Divide this by time and you get a rating or power output. There are losses due to friction in the pipe and mechanical inefficiencies of the machinery. It is green and built with considerable respect to the surrounding environment. The compensation flow calculation means that the river habitat continues to get water even if we have to switch the light off; trout before TVs if you like..
I see my phone has cleverly mapped this for me on blip