This study, carried out by Regional Plan Association, was designed to pinpoint current physical development within the study area, as defined in Section I. Additionally, data on current population and income; land area; and floor space by grade level, was gathered for the purpose of determining the extent to which severe flooding would affect life and property in the area. The study shows that there is a total of 25,600 ‚acres in land and water space within the flood plain, of which 16,200 is developed and about 9,400 undeveloped. The residential population in the flood plain as of 1970 is about 380,000, at a density of approximately 123 per acre. Over 500 million square feet of floor space is found within the tidal flood plain, much of which is accounted for by manufacturing and warehousing facilities; transportation depots; and residential dwellings.