I am a newbie and in the design phase of a two tiered waterfall/pond system. I have two basic questions right now. First, my waterfall and upper pond will be the most prominent feature to the viewer. I would like the upper pond (8 feet diameter x 2 feet deep) to be larger than the lower (6 foot diameter) pond. there will be a stream about 45 feet long dropping about 6 feet in elevation from the upper to lower pond. I plan on running the pump 24x7, but there will be times I will want to shut it down for maintenance and such. How to I keep the water in the stream from flooding and overflowing the lower pond when the pump is shut off? Can I retain the water in the stream without it being wasted and overflowing the the lower pond? And is there any issue I am overlooking by having a larger pond at the top?
My second main question is about screening fish. I would like some gold fish only in the upper pond since it is most prominent. Is there a way to design a screen in the outflow of the upper pond to keep fish from being washed down steam and into the pond below? My thought is to use rabbit cage mesh screen and cut it the shape of the stream contour and attach it to a log sitting across the stream channel. Does this sound about right? See the attached cross section sketch for a visual.
My second main question is about screening fish. I would like some gold fish only in the upper pond since it is most prominent. Is there a way to design a screen in the outflow of the upper pond to keep fish from being washed down steam and into the pond below? My thought is to use rabbit cage mesh screen and cut it the shape of the stream contour and attach it to a log sitting across the stream channel. Does this sound about right? See the attached cross section sketch for a visual.