What does "running water makes money" mean?

"Running water to make money" means that wealth is as endless as running water.

"Running Water to Make Money" mainly depicts the running water on the mountain, with a long history of artistic conception and landscape.

Waterfalls fly down and pour thousands of miles, just like rolling financial resources, unstoppable.

Water will have vitality when it flows, while money will probably increase in value when it flows. The faster you move, the more you earn.