The cost of water might be tiny if you're drinking it, but it's not tiny when you're using it to grow food or use it for other industrial processes. One almond

The cost of water might be tiny if you're drinking it, but it's not tiny when you're using it to grow food or use it for other industrial processes. One almond kernel requires 3-4 days worth of drinking water to grow. Also, humans in many places are using groundwater that's thousands of years old. In those places we can't observe any effect humans have had, because we're effectively tapping into reservoirs that predate human usage of that water. Eventually that's going to run out.