(a)(1) Except as provided in paragraphs (2), (3), and (4) of this subsection, the government shall be subject to zoning.
(2) Any governmental land uses that were either existent or substantially planned, documented, and invested in prior to May 23, 1990, shall not be subject to zoning.
(3) The use of government-owned property on Lot 276 in Square 1282, which is located at 3050 R Street, N.W., as a residential treatment and special education facility for not more than 24 emotionally disturbed children, ages 6 to 12 years, and as a treatment and special education facility for not more than 15 emotionally disturbed children, ages 6-12, who do not reside at the facility, shall not be subject to zoning.
(4) The government’s use of property on the former site of the United States Naval Air Station communications facility located in the northeast corner of the east campus of Saint Elizabeths Hospital as a facility to send and receive 911 or other governmental emergency communications shall not be subject to zoning. Any governmental use of this property for other purposes or any non-governmental use of this property shall be subject to zoning or review and approval by the Council.
(b) The Mayor shall within 16 months of April 8, 2011, propose amendments to the zoning regulations or maps to eliminate any inconsistency of the zoning regulations with the Land Use Element of the Comprehensive Plan.