law: The Delhi Municipal Corporation Act, 1957
  320. Prohibition of structures or fixtures which cause obstruction in streets.-
  (1) No person shall, except with the permission of the Commissioner granted in this behalf, erect or set up any wall, fence, rail, post, step, booth or other structure whether fixed or movable or whether of a permanent or temporary nature, or any fixture in or upon any street or upon or over any open channel, drain, well or tank in any street so as to form an obstruction to, or an encroachment upon, or a projection over, or to occupy any portion of such street, channel, drain, well or tank.
  (2) Nothing in this section shall apply to any erection or thing to which clause (c) sub-section (1) of section 325 applies.