You can only evaporate per hour what the system takes the rest is down
the drain, a humidifier should not use enough water to make a big
difference. If your thermostat has a hour meter you can roughly figure
out run time and measure the waste overflow per hour, Maybe a smaller
line or reducing the flow will help, I do less laundry loads in winter
and water outside in summer, in winter even with a humidifier water use
is much less.