ground is actually a vector of loss for water.

if you look at household water consumption, most places in north america treat their water and return it to a freshwater source. you can scale cities very wide and water use might go up, but the consumption rate is actually low. more depending on how much people water their lawns.

farms on the other hand 'spray water on the ground' but it actually removes the water from the freshwater source and needs to be replenished.

leaks is water loss/consumption. human activity is no guarantee. leak in this case is still bad.

The freshwater source might be an aquifer so staying in the ground isn't a loss to the local water supply, though it may be a loss in regards to effort to move and treat it.