I'm having trouble with water in my city. I have four pumps and three treatment plants and it's more than enough to cover my population. I have pipes covering the entire map and my water budget's maxed out. Still, EVERYONE is abandoning due to 'Lack of Water.' How can I fix this?
You need to have enough water being pumped, as well as sewage. Note the consumption is less than capacity in both water and sewage, seen here:
You also need to make sure your pipes are connected to the buildings, denoted by a darker blue coloring in the water view, seen here:
If either of these are not true, you will see the No Water notification pop up on a building.
My answer to you is 11 months too late, but I hope this'll help others as well. My problem was that I had two different places for sewage and water pumping and I hadn't connected two of those places. That's why people in other island were complaining about not having enough water in their buildings.