I began this with the bigger pond in 2002. I hired a guy with a small backhoe to dig the 3' hole and I did all the rest. I put in the stream bed a few years later. I used the soil to create a short raised fall with a skippy filter putting water into the pond. Then last year I had an inspiration to move the filter back 8 feet and build a smaller, raised pond to feed the big pond, and again, I hired someone to dig the hole and I did all the rest. I got a plan to build the bridges using 2 X 12 lumber. Create the span with a piece of 1/2 " pvc to trace the arc and then I cut it with a scroll saw. The bridges look nice, I think.