The Southern California Association of Governments shall submit its plan elements to the south coast district board by June 1 of each odd-numbered year, except in the case of a delayed submittal as provided in subdivision (a) of Section 40463, for incorporation into the air quality management plan. The district shall combine the association’s plan elements with the south coast district elements as specified in subdivision (a) of Section 40460. Each agency shall prepare and submit all necessary documentation, including that of public and intergovernmental involvement.