The Pueblo San Diego watershed is the smallest hydrologic unit (HU) in San Diego County, encompassing approximately 60 square miles of predominantly urban landscape in the cities of San Diego, La Mesa, Lemon Grove, and National City.  The watershed contains the smallest proportion of unincorporated area (0.3%) of the HUs within the county.  The population of the Pueblo San Diego watershed is approximately 500,000 residents, making it the county’s most densely populated watershed.  Approximately 75% of the watershed is developed.  Residential, retail/ office, and industrial land uses account for 45%, 11%, and 10% of the total, respectively.  In addition, there are relatively large percentages of land used for transportation corridors and highways.   Due to the high level of existing urbanization in the watershed, only small amounts of additional land is projected for development over the next 15 years.