Mitigation Credits; Authorizes DEP & water management districts to release mitigation credits to certain mitigation banks under specified conditions & to authorize use of mitigation credits available within surrounding basins or within specified regions; provides circumstances under which mitigation credits are deemed unavailable in basin; requires affidavits from mitigation banks before certain mitigation credits are released; authorizes certain projects to use mitigation banks regardless of whether they are located within mitigation service area; requires DEP to begin rulemaking by specified date.