Utilization of Marginal Lands for Urban Development

The problems and costs of creating useful land from marginal wetlands around cities are becoming increasingly important to planners and engineers. Such lands are below water or occasionally flooded, are underlaid by soft and highly compressible organic alluvium, and frequently are covered by garbage and solid refuse. Making usable land requires fill to raise the grade above flooding. The major problem is excessive settlements under the load of this fill. Precompression by surcharge loading, possibly with sand drains, is required to minimize future settlements and make land acceptable for light buildings, streets, and municipal services. Heavier buildings require pile foundations extending through all compressible soils and pile-supported waterfront structures may be required. In 1967, costs for land development range from $30,000 to $150,000 per acre and additional costs of foundations for nine-story buildings range from $9.00 to $17.00 per sq. ft. Waterfront developments with deep water perimeters may cost upward of $300,00 per acre. Data are provided for estimating design requirements and site development costs on a comparable basis.