(a) This chapter applies to any interest created on or after September 1, 1983, that complies with this chapter, whether designated as a conservation easement or as a covenant, equitable servitude, restriction, easement, or otherwise.
(b) This chapter applies to any interest created before September 1, 1983, if it would have been enforceable had it been created on or after September 1, 1983, unless retroactive application contravenes the constitution or laws of this state or the United States.
(c) This chapter does not invalidate any interest, whether designated as a conservation or preservation easement or as a covenant, equitable servitude, restriction, easement, or otherwise, that is enforceable under other law of this state.