Agua Mansa was once the largest town in San Bernardino County. The name, meaning "peaceful waters" was given by the settlers who believed themselves safe. In 1852(?), however, the Santa Ana River flooded. Waters climbed so high that only the village's cemetery, located on a low bluff, was left. Submitted by: Joel GAzis-SAx.

Agua Mansa/San Salvador, CA: These 2 settlements, on the Bandini Donation, of Rancho Jurupa, were composed of New Mexican Colonists, who had moved there in 1845 from Politana, on Rancho San Bernardino. After dissatisfaction with certain conditions at Politana arose, Juan Bandini invited the settlers to leave & relocate to a parcel of land he had donated. The parcel lay on both sides of the Santa Ana River. Agua Mansa on the north and west bank; San Salvador on the south and east bank. These colonists were desirable at the time, as a protection against the inroads of unfriendly Indians. Nothing remains of Agua Mansa today, except the burial ground, on the hill above the river, near which also once stood the chapel. This cemetery is reported to be the oldest in the county. Agua Mansa means "gentle water", but the Santa Ana River was anything but gentle in 1862, when the homes of both settlements were completely washed away. The chapel & cemetery were on high enough ground to escape the rampaging river. The cemetery was restored in the 1850's by interested citizens, including descendants of some of those buried there. It is located about 3 miles sw of Colton, on Agua Mansa road, east of it's intersection with Riverside Ave. San Salvador, was later known to American pioneers as "Spanish Town, and was also called "La Placita de Trujillo". Only a remnant or two, of Spanish Town, now in Riverside County, remain today. Submitted by Bob Stelow.

http://www.sbcounty.gov/museum/branches/agua.htm