[Lands included in district; two or more artesian basins in

one district.] Any artesian conservancy district organized pursuant to the provisions of this act [73-1-1 to 73-1-13 and 73-1-16 to 73-1-23 NMSA 1978] shall include all lands overlying any such artesian basin and any land outside of the boundaries thereof upon which waters from such basin are being used, either for private, public, commercial, domestic or irrigation purposes, or otherwise. Two or more such artesian basins or reservoirs may be embraced in the same conservancy district, where the same are so closely related, geographically or otherwise, that the waters therein can more surely and effectively be conserved by the unified control of one district, and where the improvements contemplated will tend to conserve the waters in each basin so included.