El Capitan Dam Spillway Near-Term Repair
Owner: City of San Diego
Project Name: El Capitan Spillway Near-Term Repair
Location : El Capitan Reservoir Dam, Lakeside, CA
Designer: Kleinfelder
Contractor: Orion Construction Corporation
Delivery Model: Design-Bid-Build
Contract Value: $3,807,324
Schedule: February 2024 – September 2024
Scope: This project brought the City of San Diego into compliance with California DSOD requirements for repair of deficient concrete spillways. It included concrete repairs to the upstream and downstream ogee spillway walls, left and right retaining walls, upstream ogee slab, and downstream spillway slab at the El Capitan Dam. The project repaired all degraded concrete, spalls, and boulder impact areas within the spillway channel floor and walls. Repairs included about 400 cubic feet of spall repairs using cementitious high-strength mortar, 1200 lineal feet of structural crack repairs by injection of high-strength epoxy resin, and 6000 lineal feet of shrinkage crack repairs utilizing polyurethane joint sealant. The project also included removal of non-native vegetation growing adjacent to the spillway chute.
Challenges: The project is in a remote area of East San Diego County within the reservoir property owned by the City of San Diego. The city only allowed access to the spillway using the road crossing over the dam. However, loading on this road was limited to passenger cars and pickup trucks, so we obtained permission from the US Forest Service to use one of their dirt service roads to access the north side of the spillway for the heavy vehicles and equipment needed to construct the project. We graded the dirt road, cleared vegetation, and installed steel plates to bridge over drainage swales to make the road passable for our heavy vehicles and equipment. We staged a 90-ton crane next to the spillway walls to lower equipment and repair materials into the spillway and erected a 35-foot-high stair tower from the the bottom of the spillway to the road elevation for our workers to access the work sites.
Results: This project was constructed with in-house labor trained by a Sika Corporation technical representative as certified applicators of Sika repair mortars and epoxy grouts. 11,000 hours of work was completed with zero reportable incidents. The repairs performed by our company enabled the City of San Diego to comply with the California Division of Safety of Dams (DSOD) spillway reevaluation program, keeping the integrity of the spillway intact and functioning and ensuring the continued viability and regulatory compliance of the El Capitan Dam spillway.
