In 1990 a report, concurrent with an archaeological investigation of the Santa Fe Plaza,  was prepared locating the Spanish Colonial cienega.  The report used soils tests made for development in the area, the tests submitted to the City as part of the development review process.  As part of the analyses, the tests identified the cienega soils as having a black, dense appearance, sometimes described as being like “black Louisiana gumbo.” The soils tests showed that the cienega extended to the south and east of the plaza, suggesting why occupation by the Spanish did not occur in that area.  It also shows why the area was restricted to pasture for the presidio horse herds until the early 1800s, and why certain buildings in the downtown, even today, use sump pumps to remove water in their basements.

As part of the analyses, the tests identified the cienega soils as having a black, dense appearance, sometimes described as being like “black Louisiana gumbo.” The soils tests showed that the cienega extended to the south and east of the plaza, suggesting why occupation by the Spanish did not occur in that area.  It also shows why the area was restricted to pasture for the presidio horse herds until the early 1800s, and why certain buildings in the downtown, even today, use sump pumps to remove water in their basements.