owner's tenant refuses to turn on shared water spigot

In our condominium, we have shared water spigots. Some units have one in the front and one in the rear, and then some have only one front or rear of the unit. These are attached townhouse-style units with rear patios and space for individual units to do plantings within the rules and regs of the association.
During the landscaping season, May 15 to Oct. 15, in our rules and regulations, those that have spigots to turn them on so that landscapers and their neighbors can use them to water when needed.
An owner's tenant has refused to turn on the rear spigot (she uses it to water her plants)because she doesn't get along with her neighbor, who happens to be a trustee.

The owner of this unit has been contacted many times for various issues because of this tenant( planting on areas that are not part of that units area) using rocks from a retaining wall to decorate her exclusive space and other issues that several of her neighbors wish the owner would find a more suitable place for her to rent.
She has been abusive to the trustees and nearby neighbors. Contacting our property attorney every time she does something gets pretty expensive. Although we bill back, but it's not paid quickly, and the owner is not timely.
Wondering if we should send a stern letter to the owner and invite him to meet with the trustees to discuss all of the annoying and rule infractions she is causing.
I welcome all thoughts and suggestions.

Are the bylaws and/or CC&Rs crystal clear that the owner (or his/her tenant) must open the valve supplying water to the spigot?

Do the bylaws and/or CC&Rs allow for fines?

If so, set up the fine schedule so that repeat violations within a certain time period result in much higher fines.

Is this condominium subject to the Massachusetts Condo Act?

Thanks for the reply We are mass condo act and our bylaws allow for fines.

Instruct your corporate council to send a letter compelling the owner to comply and send a copy to the tenant.

If the HOA pays the water then find out if can turn off the water. We are not talking long term. Just enough to scare them into realizing the power the HOA has if not following the rules... Talk to lawyer and consult your rules first. We could shut off water in our HOA for non payment.
Y suggestion is to make a pipe extension for the HOA access. They can have their spigot but the HOA can have theirs accessible too. In a common area and maybe with a lock...