(1) The department shall use area of wetland as the default credit unit for calculating credits at a bank site.

(2) The department shall determine the number of potential credits at a bank using a credit conversion rate.

(3) The credit conversion rate uses a ratio of area of activity such as reestablishment, creation, rehabilitation, enhancement, or preservation to credits generated at the bank site (area of activity: Credit).

(4) Except as provided in WAC 173-700-320, the department must determine the credit conversion rates for individual banks from within the ranges specified in WAC 173-700-313 and 173-700-318.