Coanda Plate on Hayewater Gll Hydro

I went to examine the water intake on the gill by Hayeswater. The odd thing is that although water pours equally onto the top of the weir and through the by-pass, no water is visibly coming off the bottom of the weir. I went to inspect. It is made of thin wire and the water passes through into the hydro-electric pipe. It is said to work by the Coanda Effect. On a convex surface, the fluid tends to stick to the surface. I wondered why it needed to be such a fancy idea rather than just a wire filter. I suppose that debris will not be pulled to the surface and will carry on in accordance with Newton's Laws of Motion. Perhaps debris would have sat over and blocked the grill of a conventional filter.
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