After fire and landslides damaged a large portion of the water supply flume, and floodwaters inundated the powerhouse, El Dorado Irrigation District constructed a new two-mile tunnel to convey water below landside prone areas, and to repair and flood-proof the powerhouse.

Providing access for the tunnel-boring machine (TBM) to the site was a challenge and Carlton conducted a structural study of a turn of the century, three-span riveted steel and timber bridge for the purposes of supporting the TBM. After providing recommendations, we worked with the contractor on methods of safely transporting the TBM. Carlton also provided consulting services and structural engineering design and construction documents for flood proofing measures for the powerhouse.