Fuss & O’Neill was contracted to conduct visual inspections of Lawton Valley Reservoir Dam, a 39-foot-high, 2,475-foot-long water supply dam, which was originally constructed in the 1920s.

The dam is classified as a high hazard structure and was showing signs of deterioration at the 600-foot-long concrete spillway. The inspections led to providing continued assistance regarding planning, maintenance, and repair of the dam. Our team performed field investigations of this dam’s embankment and spillway structure, including a dive inspection of a low-level intake structure, structural inspection and coring program of the concrete spillway discharge channel, a subsurface drilling program of the embankment and downstream toe area, and field topographic and wetland surveys. We completed seepage analyses in support of design of a filter drain below a section of the spillway discharge channel to be removed and replaced. We prepared permit application materials, including design drawings and specifications for repairs to the discharge channel and deficiencies on the adjacent embankment. We created preliminary and final design for improvements to the spillway discharge channel. We managed surficial drainage and performed a subsurface soil and groundwater elevation investigation.