D.C. Code § 34-1901.01

The Mayor of the District of Columbia shall not permit or authorize any additional telegraph, telephone, electric lighting or other wires to be erected or maintained on or over any of the streets or avenues of the City of Washington; provided, that the Mayor of the District may, under such reasonable conditions as he may prescribe, authorize the wires of any electric light company existing on July 18, 1888, and then operating in the District of Columbia, to be laid under any street, alley, highway, footway or sidewalk in the District, whenever in his judgment the public interest may require the exercise of such authority, such privileges as may be granted hereunder to be revocable at the will of Congress without compensation and no such authority to be exercised after the termination of the 50th Congress.