Early in 2010, SFDPW issued an emergency declaration as a result of severe erosion of the bluff adjacent to the Great Highway, between Sloat Boulevard and Skyline Boulevard. The eroded bluff has caused the closure of two southbound lanes of the Great Highway and threatened the stability of the 14-foot diameter Lake Merced Transport and Storage Tunnel located under the road. A State emergency was declared Emergency Relief funding from Caltrans was allocated.
A rock revetment was installed about 425 feet long at the toe of the bluff to prevent further bluff toe failure and additional damage [Phase 1]. M&N was subsequently contracted to provide geotechnical engineering, structural engineering, design, and construction support services to prepare final drawings and specifications on an accelerated schedule basis for a temporary bluff top and face stabilization, protection of the Lake Merced Transport Tunnel, restoration of the roadway support system, drainage systems and reopening of the southbound lanes for traffic.