Remember Electric Company and Water Works? Conservative investments, not like Boardwalk or Place Place. Here's the collective wisdom of the value of these utilities as investments:
"The utilities are decent "fire and forget" properties, which pay for themselves quickly. Think of them as equivalent to owning two railroads, but paying a bit better because you can't improve them further. They don't have the same explosive-growth potential of railroads or properties, but they're cheaper. You're not going to bankrupt anyone with them, but they can be decent money-makers over the course of the game. They're better in the early game for fast and easy income, but later on they're more valuable simply as squares you can land safely on; everyone has become too rich to care much about such small rents."
