Urbanization's Drainage Consequence

A computer methodology (URB DRA CONS) for the preliminary costing of flood control facilities resulting from alternate land use distributions in the tributary watershed is presented including pilot application to a 15 sq mile watershed in San Diego County, CA. Channel flows for various recurrence intervals with any given pattern of land use and channel improvement are determined using a computer program patterned after the U.S. Soil Conservation Service hydrologic procedures. Results from the pilot study revealed that changes in land use and channel improvement are often about equally responsible for the increased flow from urbanization. The approximate cost of another computer program that seeks the least-cost design of channel cross section through reiteration. The application of URB DRA CONS methodology provides information on the flood protection requirement consequences of land-use alternatives.