Are there occupancy limits on rental units for people not related by blood or marriage?

Very small 2-unit Condo Building. Other owner leases out their unit. I and other unit owners are the Trustees. Per CCRs, there are occupancy limits. A unit can't be rented out to more than one family unit or by more than 2 people unrelated by blood or marriage. Currently, more than 5 people have been living in the other unit. 

Water use is the issue, as it's a common expense and our usage/bills have more than tripled since they ALL have moved in. We've drawn monies from our reserves to cover the increase, but even that didn't cover the utility bill increases and I put in quite a bit of extra money in excess of my required condo fees to cover the increased utility expenses. 

The other unit owner reimbursed me half the costs but I feel like I shouldn't probably have even been so generous as to pay 50% since clearly the only reason for the increase is because more people than allowed are living in the other unit. 

Is my only recourse suing the other owner, or can I impose fines as outlined in our CCRs or would the other unit owner need to approve the fines too? Could I seek some type of emergency injunction possibly for relief? All leases are supposed to comply with our CCR's per the language in our CCR's or they are considered null and void.