Spotting opportunities takes a little trial, error, and risk. Always some sort of risk involved when investing in something as you well know. However, it comes to something as simple as Supply and Demand. If there's demand for it, it will be worth something to someone. How much that is really does depend on the amount of demand there is for it. Water for example, is a good investment due to the human race not being able to supply without it. Bitcoin is a good investment because of many different reasons, but for mainstream attention? Because, people will get sick of the control that the banks have with your money.
Has anyone considered investing in clean water? Is there a market for that? We are polluting and destroying our world every day. What if in 10-20 years we will have a shortage of drinkable water?!
The water industry is a multi billion pound market. Most countries don't even own their water sources, and foreign countries such as China, and Spain own them. I don't know the calculations on shortage of drinkable water, but when you consider that a lot of the world currently doesn't have potable water its a good investment. Even well developed countries don't have the safest practices. United Kingdom, and USA inject chlorine into the water supply at high strengths, and then later flush it out. Depending on the countries regulations I know that the United Kingdom have various different ones. Wales, for example injects chlorine at a specific strength (which I can't remember right now...) and then they flush it through 16 hours later, take a sample, and see if its all within the right parameters. They do this for each leg of the water main. Reservoirs, and treatment plants are also sampled every week or two. As far as I remember out of the UK only Wales own their water. English water is owned by a foreign country. Hence "Welsh Water" being the water board. I might be wrong on English water/Scottish water. But, I'm fairly sure. Wales also doesn't have fluoride within the water supply due to complaints in the late 90s about eroding of teeth. I'm not sure what the investigation involved, but I believe it was removed up until recently it may have been reintroduced, but I'm not sure. Of course, we know that Fluoride is actually beneficial to the teeth within moderation hence the reason USA uses it. However, there are certain demographics which are fighting for it to be removed. What I'm trying to get at here is that its not as simple as letting the mountains filter your water for you. There's a huge investment within the water industry to assure that its safe for its consumers. But, also how it ties into other areas of life like health (teeth).
In fact, water is so important that surrounding countries buy water supplies off other countries. England pays millions of pounds per year for Scotland, and Welsh water to be piped miles down into their land. That has to be regularly maintained, and checked. I'm unsure what regulation it comes under though.