So, I'm loving the addition of landfill in 0.13.x, but I'm wondering if it's a little lob-sided as a tool? Once you pave over a lake, it's gone for good. You're also kind of at the mercy of the map generator with regards to where you can place your steam engines.
What I'm thinking is for there to be a tool that does the opposite to the landfill - either allowing the player to manually dig a new reservoir hole or by designating areas and allowing robots to do it.
Then once that was complete, either running pipes & pumps from existing water sources to fill them, or by using some kind of mass fluid transfer system for longer distances.
Possibly this could be accomplished in a similar manner to transferring oil by putting it into barrels (which I always thought was a little bit inefficient), or by creating a new train tank car like one of these:

..and some kind of pipe connector that would link up at stations. This would also be quite useful for other types of liquid transfers over long distances.
I'm really not a fan of the 'load small amounts of oil into individual barrels' method which is currently in game (and still confused why this is only available for oil and not for any of the refined by-products), so something like this could open up a lot more possibilities with regards to base placement and layout, especially for large, spread out bases.