Visualize it done and with every rock and pebble where you want it. Devote mind to forming a clear vivid mental image.
Imagine (its free to imagine) the Koi Water Garden, complete with canapy of redbud tree over the water, complete with Koi swimming in the clear water, complete in all ways; pump in place and pumping water through the filter and flowing back into the pond down a three-foot streambed and over a short waterfall, cascading into the pond creating ripples perpetually rolling across the water.
I did this and I now have a Koi Water Garden even better than I had imagined. Visualizing how I wanted it to look set it all in motion.