Your Government agencies are much more cooperative than they are here in South Central Nebraska.  Only way to get new irrigated acres is to get approval from NRD board to move some existing irrigated acres to the new ground and revert the old ground to dryland.  We went thru this when we converted some gravity  irrigated to pivots. Even though the land was all on our own farm. You can buy irrigation rites from someone else but it is getting pricey. Also here the FSA classifies the non cropped acres ( broken out pasture) as Sodbusted and are not eligible for any program payments. Sodbusted acres also have some special rules when it comes to crop insurance.  Make sure you check with them all.