Sonaji experienced only slight depopulation during the LF2. Sector C has a population index value of 368 (6.5 ha), as opposed to 383 for the LF1 Sector B. This is an annual growth rate of -0.02%, less than half the rate of Chiripa. Most of that decline may be attributed to a movement of population to adjacent sites which experienced growth, especially Kumi Kipa (T-272) and Kollin Pata (T-322).
In the LF2, and possibly during the LF1 as well, Sonaji seems to have been integrated with Kumi Kipa and Kollin Pata, forming a single community. While the latter two sites seem to have been primarily residential, with little evidence of elite or ceremonial architecture, Sonaji itself seems to have been relatively specialized, as ceramics and architecture seem to show. It may very well have been the residential locus of a local elite, as well as the location of the principal public architectural complex on the Taraco Peninsula. This situation remained unchanged into the Tiwanaku Period. The three sites of Sonaji, Kumi Kipa and Kollin Pata will be referred to collectively as the Santa Rosa group (see sections 7.2.1, ).