R.I. Gen. Laws § 46-3-14: Apportionment of assessments.

Whenever any assessment is made as herein provided, the amount to be raised thereby shall be apportioned among the properties benefited according to such rule as the legislative body may adopt; provided that no benefits shall be assessed against any property in excess of the special benefit to accrue to the property. The legislative body may make reasonable allowances when for any reason the particular condition or situation of any property requires the allowance.