{"id":3238,"date":"2025-06-13T09:45:32","date_gmt":"2025-06-13T17:45:32","guid":{"rendered":"https:\/\/lettisci.com\/?page_id=3238"},"modified":"2025-10-06T09:00:43","modified_gmt":"2025-10-06T17:00:43","slug":"perris-dam-seismic-remediation-and-seepage-recovery","status":"publish","type":"page","link":"https:\/\/lettisci.com\/?page_id=3238","title":{"rendered":"Perris Dam Seismic Remediation and Seepage Recovery"},"content":{"rendered":"\n

Seismic Safety and Water Resource Resilience<\/strong>, California Department of Water Resources (DWR)<\/em><\/p>\n\n\n\n

Located in Riverside County<\/strong>, approximately 60 miles east of Los Angeles, Perris Dam<\/strong> is a critical part of California\u2019s State Water Project<\/strong>, serving as the terminal storage facility for the East Branch of the California Aqueduct<\/strong>. Since its construction in the early 1970s, the dam has provided essential water supply for recreation, wildlife habitat, and millions of Californians.<\/p>\n\n\n\n

Lettis Consultants International (LCI)<\/strong> has played a key role in supporting the California Department of Water Resources\u2019 (DWR) long-term efforts to ensure the seismic safety and hydrologic performance<\/strong> of Perris Dam<\/strong>, a critical water infrastructure facility in Southern California.<\/p>\n\n\n\n

\"\"
Image credit: California Department of Water Resources (2023)<\/figcaption><\/figure>\n\n\n\n

To address a potential liquefaction hazard<\/strong> in the dam\u2019s foundation, DWR launched a major Seismic Remediation Project<\/strong>. LCI partnered with AECOM to provide full-time construction oversight<\/strong> during installation of cement deep-soil mixing (CDSM) cells<\/strong>, including 24-hour supervision of the ground improvement, validation coring, and real-time response to contractor RFIs. The project also included foundation excavation, replacement of upper foundation materials, expansion of the horizontal filter and drain zones, and installation of a downstream stability berm.<\/p>\n\n\n\n

In support of the Seepage Recovery Project<\/strong>, LCI collaborated with other consulting firms to develop a detailed hydrologic model to assess the impacts of seepage recovery on the Perris North and South groundwater subbasins<\/strong>. This work supports DWR\u2019s evaluation of dam safety under active seepage recovery and guides placement of new recovery wells.<\/p>\n\n\n\n

\n
\n

LCI\u2019s contributions spanned:<\/strong><\/p>\n\n\n\n

    \n
  • Geologic and geophysical site characterization<\/li>\n\n\n\n
  • Liquefaction and subsidence assessments<\/li>\n\n\n\n
  • Instrumentation and construction monitoring<\/li>\n\n\n\n
  • Hydrologic modeling and GIS\/graphics support<\/li>\n\n\n\n
  • Technical workshops, SME consultation, and 3D modeling<\/li>\n\n\n\n
  • Database management and analysis of CDSM pre-drill and grouting records<\/li>\n<\/ul>\n<\/div>\n\n\n\n
    \n
    \"\"<\/figure>\n<\/div>\n<\/div>\n\n\n\n

    Together with DWR and project partners, LCI helped enhance the long-term safety and resilience<\/strong> of Perris Dam\u2014protecting vital water resources and infrastructure for the state of California.<\/p>\n\n\n\n

    \"\"
    Image credit: California Department of Water Resources (2023)<\/figcaption><\/figure>\n\n\n\n

    <\/p>\n","protected":false},"excerpt":{"rendered":"

    Seismic Safety and Water Resource Resilience, California Department of Water Resources (DWR) Located in Riverside County, approximately 60 miles east of Los Angeles, Perris Dam is a critical part of …<\/p>\n","protected":false},"author":1,"featured_media":3239,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-3238","page","type-page","status-publish","has-post-thumbnail","hentry"],"_links":{"self":[{"href":"https:\/\/lettisci.com\/index.php?rest_route=\/wp\/v2\/pages\/3238","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lettisci.com\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/lettisci.com\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/lettisci.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lettisci.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3238"}],"version-history":[{"count":5,"href":"https:\/\/lettisci.com\/index.php?rest_route=\/wp\/v2\/pages\/3238\/revisions"}],"predecessor-version":[{"id":3336,"href":"https:\/\/lettisci.com\/index.php?rest_route=\/wp\/v2\/pages\/3238\/revisions\/3336"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/lettisci.com\/index.php?rest_route=\/wp\/v2\/media\/3239"}],"wp:attachment":[{"href":"https:\/\/lettisci.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3238"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}