Archaeological Resources Assessment for the 1024 Mateo Street Project, Los Angeles, California APRIL 2019 PREPARED FOR Mateo Arts, LLC PREPARED BY SWCA Environmental Consultants This page intentionally left blank. Archaeological Resources Assessment for the 1024 Mateo Street Project, Los Angeles, California Prepared for Mateo Arts, LLC 1875 Century Park East, Suite 1750 Los Angeles, CA 90067 Attn: Daniel A. Abrams and Sammi Shaaya Prepared by Chris Millington, M.A., RPA and Trevor Gittelhough, M.A., RPA SWCA Environmental Consultants 51 West Dayton Street Pasadena, California 91105 (626) 240-0587 www.swca.com SWCA Project No. 055465.00 SWCA CRRD Report No. 19-220 April 2019 Keywords: CEQA; archaeological sensitivity assessment; City of Los Angeles Department of City Planning; Arts District; Zanja No. 1; residential and industrial refuse and building foundations; 2018 E Bay St, 2016 E Bay St, 2010 E Bay St, 2006 E Bay St, 2006 1/2 E Bay St, 1000 S Mateo St, 1000 1/4 S Mateo St, 1010 S Mateo St, 1012 S Mateo St, 2023 E Sacramento St, 2023 1/2 E Sacramento St, 2019 E Sacramento St, 2019 1/2 E Sacramento St, 2015 E Sacramento St, 2015 1/2 E Sacramento St, 2011 E Sacramento St, 2009 E Sacramento St, 2007 E Sacramento St, 2005 E Sacramento St, 2001 E Sacramento St, 1026 S Mateo St, 1024 S Mateo St, 1020 S Mateo St, 1018 S Mateo St, 1014 S Mateo St; Los Angeles; Hollywood quadrangle; Township 1 South, Range 13 West, Section 9 Archaeological Resources Assessment for the 1024 Mateo Street Project, Los Angeles, California MANAGEMENT SUMMARY Purpose and Scope: Mateo Arts, LLC (the Applicant) retained SWCA Environmental Consultants (SWCA) to conduct an archaeological resources sensitivity assessment in support of the proposed 1024 Mateo Street Project located in the city of Los Angeles, California, within the Arts District neighborhood. The Applicant proposes to construct a mixed-income, eight-story mixed-use development containing approximately 106 Live/Work condominiums units and approximately 119,843 square feet of commercial space that includes 13,978 square feet of retail and 13,126 square feet of restaurant space (the Project). The Project site fronts along Mateo, Bay, and Sacramento Streets, and consists of 62,111 square feet (1.43 acres) of lot area. The following report addresses archaeological resources for the purpose of compliance with the California Environmental Quality Act (CEQA) and with relevant portions of Public Resources Code (PRC) Section 5024.1, Title 14 California Code of Regulations (CCR) Section 15064.5 of the CEQA Guidelines, and PRC Sections 21083.2 and 21084.1. The City of Los Angeles Department of City Planning (City Planning) is the Lead Agency under CEQA for the Project. This report documents the methods and results of a confidential records search of the California Historical Resources Information System (CHRIS), sacred lands file (SLF) search through the Native American Heritage Commission (NAHC), and archival research used to evaluate the presence or likelihood (i.e., sensitivity) of archaeological resources within the Project site and to inform the analysis of potential impacts in accordance with Appendix G of the CEQA Guidelines. Dates of Investigation: On March 18, 2019 SWCA conducted a confidential search of the CHRIS records at the SCCIC on the campus of California State University, Fullerton. On April XX, 2019, SWCA received the results of a SLF search from the NAHC. Summary of Findings: This evaluation included a review of historical archival sources and archaeological records. No tribal cultural resources were identified in a CHRIS records search within the project site and a 0.5-mile radius. The SLF records search did not identify any sacred lands or sites in the project site. The closest known sites with Native American-affiliated materials on file at the CHRIS are mapped in approximately 1.5 miles north of the Project site, between the Los Angeles Plaza, Union Station, and MWD Headquarters building. The Gabrielino village known as Yaanga and several other important Historic- period Gabrielino sites (e.g., Pueblito. Rancheria de los Poblanos, and two unnamed rancherias) were located in the same approximate area, more than 1 mile from the Project site. The general proximity of the Project site to areas of known habitation, the river, and broad travel corridors has the effect of an overall increase in the sensitivity for archaeological resources affiliated with Native Americans, particularly for the physical remains of temporary open camps. Subsequent development of the Project site between the 1890s and 1910s, and multiple episodes of redevelopment through the twentieth century would have displaced any former archaeological resources affiliated with Native Americans that were once present on the surface or near surface. Sediment profiles taken from soil sample locations in the Project site are typical of floodplain deposits within the Los Angeles River floodplain and reflect a mixture of high- and low-energy deposition, which is interpreted as reducing the overall archaeological sensitivity for archaeological resources affiliated with Native Americans. Overall, SWCA finds a low potential for encountering prehistoric and Historic-period Native American archaeological resources within the Project site. One segments of the historical zanja system—Zanja No. 1—was historically located approximately 250 feet (76.2 m) from the Project site, between Mateo and Wilson Streets. A second, unnamed branch of the zanja was also mapped 300 feet (91.4 m) east of the Project site. While several overview maps depicting the zanja system trace the route of Zanja No. 1 either within or very near the Project site, an 1891 survey map was able to more precisely and reliably confirm its relative location. The survey map depicts the main channel of Zanja No. 1 as being constructed of a concrete conduit in the parcels northwest of the Project site and then transitioning into a wooden flume, within the former Leck property, directly east of the Project site. The unnamed segment to the east appears to have been constructed as an open earthen ditch, and is SWCA Environmental Consultants i Archaeological Resources Assessment for the 1024 Mateo Street Project, Los Angeles, California described as an “old ditch,” possibly an earlier route of the zanja. Because the 1891 survey map was drawn to scale and depicted streets are close to their current alignments, the map can be considered a reliable source for assessing the sensitivity for any physical remains of the zanja system within the Project site, and supports the conclusion that the project site has a low sensitivity for Zanja No. 1 and any other zanja system components. The CHRIS records search and archival research identified five archaeological resources, four of which are Historic-period sites, within a 0.8-km (0.5-mile) radius of the Project site. One additional archaeological site, LAN-4460H, was also identified in the CHRIS search, although it was located outside the 0.5-mile radius. LAN-4460H is a Historic-period archaeological site identified during construction monitoring. The site contained a substantial deposit of domestic items and structural remains associated with residential development between the 1880s and 1920s. Because the historical developments of LAN-4460H so closely resemble those within the current Project site, including the existing conditions at the time of construction, the likelihood of encountering similar Historic-period archaeological resources is considered very high. Historic-period archaeological resources could be preserved below the current ground surface, especially within any sediments identified as artificial fill. Specifically, there is potential to encounter structural remains, features, and artifacts associated with the residential neighborhood from the 1890s to the mid- 1920s. Refuse was commonly deposited in trash pits and privies prior to the establishment of sewer lines and trash services. Because these types of historical features were originally excavated into pits, which can extend several feet below the surface, they are frequently found preserved below subsequent modifications. The various industrial uses of the Project site from the mid-1920s through the 1950s are also likely to occur as archaeological deposits such as pieces of refuse, hardware, tools, buildings materials, machine parts, as well as former building foundations or other structural remains. The preservation potential is reduced in at least some portions of the Project site as a result of the construction and removal of some subterranean structures in the Project site after 1970. This includes hydraulic hoists, USTs, island pumps, a grease pit, wash-down drain, and clarifier that were identified in Phase I and II ESAs, and a Site Characterization Report. Overall, SWCA finds the Project site has a high sensitivity for containing Historic-period (non- Native American) archaeological resources. Conclusion: The depth of excavation for the Project is approximately 25 feet below the surface, which would likely require excavation of underlying alluvial sediments and removal of any overlying artificial fill. The potential for unidentified archaeological resources within the Project site is found to be high. If present, any previously unidentified archaeological resources have the potential to be significant under CEQA. The total depth of excavation required for the Project is expected to be approximately 25 feet below the surface. Without mitigation, physical destruction of an archaeological resource eligible for listing in the CRHR would result in a significant impact under CEQA. To address potential impacts to previously undiscovered archaeological resources, the Project will include retaining a qualified archaeologist (MM Arch-1), producing and implementing a detailed ARMMP (MM Arch-2 and Arch-4), and conducting a worker training (MM Arch-3). Doing so will ensure any archaeological sites are identified and determined to be historical resources or unique archaeological resources, to which project-related impacts would be mitigated on the basis of their eligibility under each CRHR criterion and as a unique archaeological resource.