Section 5-398. Unforeseeable damages; settlement or determination thereof

Whenever the owner of any private property any part of  or  interest  in
  which  shall  have  been taken under any proceeding had pursuant to this
  subchapter shall claim that the prosecution of any work done pursuant to
  such proceeding has been the proximate  cause  of  actual  and  material
  damage  to any part of such property and that commissioners of appraisal
  could not have taken cognizance of such damage pursuant to section 5-387
  of this subchapter, until the actual happening thereof  because  of  its
  unforeseeable   or  speculative  nature,  the  proper  person  or  board
  representing the city may agree with such owner as to the amount of such
  damages. If such agreement cannot be made, such owner may present to the
  commissioners of appraisal his or her claim in writing duly verified  on
  oath.  It shall be the duty of the commissioners to hear allegations and
  proofs and to proceed in like manner as  is  provided  in  the  case  of
  property  taken  pursuant  to  such  proceedings  as  aforesaid  and  to
  determine such actual damages,  if  any,  which  were  unforeseeable  or
  speculative  until  the  actual  happening  thereof.  The amount of such
  damages so agreed upon, if any, or so determined, shall be  payable  and
  collectible in the same manner as is provided in the case of awards made
  through  the  confirmation  of a report of commissioners of appraisal in
  such proceedings. In case at the time of making  any  such  claim  there
  shall  be  no  commissioners  authorized to take cognizance thereof, the
  corporation counsel, for and on  behalf  of  the  city,  shall  make  an
  application  for  the  appointment  of commissioners of appraisal in the
  manner prescribed by this subchapter, to take cognizance of such claims.
  Provided, however, that such claims shall be  presented  in  the  manner
  above  specified  within  two years from and after the completion of the
  work, the prosecution of which is claimed to  have  been  the  proximate
  cause  of such damage and that such claim shall be supported by proof of
  interest in the property alleged to have been damaged and of such damage
  and that it resulted proximately from the prosecution of such  work,  as
  aforesaid,   and  that  it  was  so  unforeseeable  or  speculative,  as
  aforesaid; and that the claim could not, with due diligence,  have  been
  presented  to  prior  commissioners  of  appraisal  subsequently  to the
  happening of the damage. In every case the payment of the amount  agreed
  upon  or determined or adjudged under and pursuant to this section shall
  be a continuing, complete, and conclusive bar to all claim of damage  by
  anyone  whomsoever  to the property concerned or any part thereof due to
  the prosecution of the work.