The board may, at the time of fixing the ground water charge, establish a method or methods to be used in computing the amount of water produced from a water-producing facility which is not measured by a measuring device.
Such methods may be based upon any or all or a combination of the following criteria:
(a) The size of water-producing facility discharge opening.
(b) The area served by the water-producing facility.
(c) The number of persons served by the water-producing facility.
(d) The use of land served by the water-producing facility.
(e) The crops grown on land served by the water-producing facility.
(f) Any other criteria which may be used to determine with reasonable accuracy the amount of water produced from a water-producing facility.