NID’s Project at Combie Reservoir Honored for Innovation

On April 24th, the Nevada Irrigation District’s Combie Reservoir Sediment and Mercury Removal Project was honored as the Outstanding Small Project of the year at the American Society of Civil Engineers Sacramento Region 2018 Project Awards and Goize Scholarship Banquet.

This project employs an innovative recovery process to remove sediment from Combie Reservoir, with the benefit of reduced sediment and mercury transport in the Bear River watershed. The Nevada Irrigation District began full-scale removal of accumulated sediment in 2018 and will continue through 2020 under a DWR grant. Sediment will be removed both in the dry and by dredging.

The effectiveness of sediment and water treatment steps will be monitored so that an adaptive management approach can be used to improve the engineering processes throughout the pilot project. Monitoring reservoir biota before, during, and after sediment removal remains a critical project performance measure. Real time monitoring of effluent will ensure that only clean water is returned back into the reservoir.

Since 2009, TSF has partnered with the Nevada Irrigation District (NID) on the Combie Reservoir Sediment and Mercury Removal Project in order to establish best management practices for removing sediment from mercury-impacted systems. If successful, this pilot project can be scaled up to yield multiple benefits at reservoirs throughout the Sierra Nevada, including water supply reliability, water quality protection and improvement, ecosystem restoration and enhanced recreation.