How can I get 100% happiness?

Previously, my city's population had a happiness of 100%. After some new building, their happiness dipped to about 90% (because there was no longer enough water or sewage treatment).
After fixing that (and creating more buildings) the happiness has risen to 99%. But, I cannot work out how to get that last 1%.
I have checked:
- fire stations
- police stations
- parks
- water
- power
- sewage
- traffic
It all seems to be OK. EA answers did not provide any new clues.
Currently, my city is at level 13.
Best Answer
If you want to get more happiness, you should built some population boost building like casino, I build many of it and the happiness never dropped below 100% although I remove all the park.
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How is happiness calculated Fallout 4?
Each human or ghoul settler can provide up to 80 happiness points by meeting their basic needs, which are: A bed in which to sleep, which counts for 10 points. For their bed to be covered from rainfall, which counts for 10 points. One unit of food production per settler, which counts for 20 points.How do you get a benevolent leader?
sometimes pathing glitches things, usually to beds but sometimes elsewhere. so never ever leave a settlement after ordering a settler to a task, until you've SEEN them path there. if you don't check all is fine and dandy, the zero food/water/beds bug has higher tendency to occur.Why is my settlement unhappy Fallout 4?
If a settlement fails to defend itself, then you'll lose a % of the items in the workbench. The amount lost depends on how tough the attackers were. Note that this is THAT settlement's "local" workbench, not all of them (if you've connected your settlements via the Local Leader perk).More answers regarding how can I get 100% happiness?
Answer 2
Maybe you should check waste management and factories and whether the dirtiness from power, sewage, waste management and factories touches the houses.
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