; and (D) benefits to disadvantaged communities identified in a plan approved pursuant to subsection (d). (4) A grant under this subsection shall be limited to 75 percent of the cost of the proposal, except that the Secretary may reduce or waive the such matching requirement if a coastal state submits to the Secretary in writing a request for a waiver with a justification as to why the State cannot meet the match requirement, and the Secretary agrees with the justification and grants the waiver. (e) Technical support to States (1) The Secretary shall take such actions as the Secretary determines necessary to support States in carrying out this section, including at a minimum the following: (A) Periodic assessment of storm flood risk and relative sea level and lake level changes along the United States coastline, including estimates of changes in storm intensity and relative sea or lake levels by 2040, 2060, 2080, and 2100. (B) Operation of an online mapping tool to describe areas at risk of temporary flooding from future coastal storms and permanent inundation as a result of sea or long term lake level changes. (C) Publication, not later than 1 year after the date of enactment of this section and periodically thereafter, of guidance for the development of State plans developed pursuant to subsection (d). (D) Establishment, not later than 1 year after the date of enactment of this section, of minimum criteria for disclosure of severe coastal flood hazards, including sea level rise, to buyers of real estate in the coastal zone. (E) Creation, not later than 1 year after the date of enactment of this section, and periodic updating, of an online dashboard describing the key features of State or local government requirements for disclosure of severe coastal flood hazards to buyers of real estate. (F) Establishment, not later than 1 year after the date of enactment of this section, after consultation with the Administrator of the Environmental Protection Agency, of standards for restoration to safe conditions of sites