Whenever the supervisors have found under the provisions of RCW
86.15.110 that a flood control improvement or stormwater control improvement initiated by any zone will be of benefit to the county as a whole, as well as to the zone or participating zones; or whenever the supervisors have found that the maintenance and operation of any flood control improvement or stormwater control improvement within any zone will be of benefit to the overall flood control program or stormwater control program of the county, the board may authorize the transfer of any funds available to the county for flood control or stormwater control purposes to any zone or participating zones for flood control or stormwater control purposes.