Write an email to the condo HOA as why including a flat rate of water bill into monthly HOA fee is a bad idea
To whom it may concern:

I am a resident at Greenwood community and hereby writing this email proposing to separate flat-rate water bill from monthly HOA fee and make it pro-rated. Here are the reasons:
1. When people don't pay for water bill explicitly, they start to feel it comes for free. Hence, they have no motivation to use water wisely. It leads to waste of water and more subtly, increase of HOA fee in the long-run since it's all running money after all.
2. It's not fair to residents with smaller condos. Although not aways true, small square footage usually means less people and less water usage.
3. People can abuse this policy. I noticed some people run commercial laundry in their condos which make the water usage skyrocket. However, no matter how much they use, they pay a flat rate each month. 

All in all, I propose to change flat rate water bill to pro-rated.

Look forward to your response.

Best,
Resident John Doe