I'm guessing the rates have jumped and the owners are no longer willing/able to absorb the cost.
If there is a water meter, there will also be a sewer charge, unless the park has its own private sewer system. Any system that gets any type of state or federal funding (loans or grants) is required to calculate the sewer charge off the water usage. It's normally at least 100% of the water rate and can be much more. The rates jump a lot when a system has been neglected for years and then has to make a lot of upgrades to avoid stiff fines from the state and feds. The sewer and water rates have to cover all the costs of upgrades.