Lake Refugio dredging project on the way

The City of Hercules (CA), at the council meeting on October 22, voted and approved the contract with LSA Associates to secure the Environmental Permits and complete the Final Design for the Lake Refugio Dredging Project.

Lake Refugio was last dredged in 2005. During large storm events, sediment is conveyed down Refugio Creek and settles to the bottom of the lake.

Over time, the lake has gradually filled, creating shallow areas that are unattractive and conducive to algae blooms during the warm summer months, when the lake is also stagnant due to lower flows.

In 2018, LSA was selected to complete the 30% dredging plans and assist in obtaining the required permits from the regulatory agencies. Substantial progress was made then; however, the project stalled when the dredging was estimated to cost between $500K- $1M.

Given the urgency of removing the sediment from the lake and the one-time General Fund/Capital Reserves monies that are now available, the city now wants the Lake Refugio Dredging Project to continue as soon as possible.

LSA’s scope of work includes a bathymetric survey, soil sampling/analysis, preparation of sediment dredging plans, and preparation of permit applications.

Preliminarily, it is estimated that the total cost to dredge, including biological monitoring and engineering support, could vary from $400K to $600K. If the dredged material has to be hauled to a disposal facility based on the soil testing results, this could add an additional $450K to the project cost.