SRI conducted a cultural resources study in support of the Reach V Brine Line Rehabilitation Project between 2014 and 2017. The project included three segments, totaling approximately 12.9 km of existing pipeline in Temescal Canyon, Riverside County, California. The project consisted of a records search and literature review of all previously conducted cultural resource studies and previously recorded cultural resources within one-quarter mile of the project area and a buried-sites testing program in a portion of Segment 3. The records search showed that a total of 74 previous cultural resource studies had been conducted within the records-search area and that 43 cultural resources—25 archaeological sites and elements of the built environment and 18 isolated artifacts—were in the records-search area. Of these, 3 archaeological sites crossed the pipeline corridor. The records search also included contacting the Native American Heritage Commission to conduct a search of their Sacred Lands File.

Following the records search, a field inspection was conducted for all three project segments. The eastern third of Segment 3 passed through deep alluvial deposits that had the potential to contain buried cultural resources. SRI conducted a buried-sites testing program within this portion of the project area to determine whether buried cultural resources were present. SRI excavated four 5-m-long trenches within the proposed pipeline alignment, each of which was at least 1.5 m deep. One piece of lithic debitage was identified within one of the trenches.

Because the pipeline was location on a County of Riverside right-of-way, the project was subject to the County’s Cultural Resources Memorandum of Understanding, which SRI followed. SRI completed an update for the project, conducting a new records search and site visit for a portion of Segment 1 to account for changes to the project scope.