Construction at Upper Rose Bar is Moving Along

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Construction at the Rose Bar Project officially kicked off on July 24th and things have been moving nonstop since.

The Rose Bar project site is located 9 river miles below Englebright Dam on land recently acquired by the Yuba Water Agency.

The purpose of this project is to create and enhance two spawning riffles for Chinook salmon and steelhead. Englebright Dam prevents gravels from moving downstream from upper portions of the watershed. In the Goldfields, the piles of hydraulic mining debris provide the gravel sizes necessary for spawning. However, because Rose Bar is so close to Englebright Dam which traps downstream movement of gravel, as the Yuba River erodes spawning gravel from this location, there is no natural source of gravel to replace it.

The main objective of this project is to add spawning sized gravels to the riverbed from locally sourced material. We will be sourcing the necessary gravel from hydraulic mine tailings in the uplands above the project and, at the same time, stabilizing the hillslope which will decrease the amount of mercury delivered to the Yuba River during rain events.

The total area of the project is about 43 acres with about 5 acres of new spawning habitat.

The primary objectives of the Proposed Project are:

1) Increase the amount of high-quality spawning habitat by modifying hydraulic (i.e., depth and velocity) and substrate conditions to within the ranges preferred by Chinook salmon and steelhead during typical spawning periods.

2) Create a design that mimics natural morphological features (e.g., riffle, pool) that would not erode significantly through typical non-flood control related operations.

3) Reduce bank erosion in the gully that may be contributing mercury contaminated soil to the Yuba River. 

This year, we will only be constructing the access road, sorting the material generated from grading and stockpiling the spawning gravel, and planting. All in water work will happen in 2024.

We had to pivot last minute and break up project implementation into 2 phases because the permitted in water work window is so narrow due to spawning in the upper reaches where the project is located.

SYRCL is also conducting weekly mercury sediment sampling to make sure we can properly manage any contaminated soils that are being moved around by construction activity. The photo below shows Summer and Rose collecting mercury samples.

Summer and Rose hunched over by a pile of dirt collecting mercury samples.
Summer and Rose hunched over by a pile of dirt collecting mercury samples.

As well, about 20 trees were removed at Rose Bar in order to grade the access road and generate material to be sorted into spawning gravel. They were carefully cut down to maintain as much structure as possible (rootwad and canopy) and then trucked to the Hallwood restoration site to be used in “large woody material” structures in the seasonal side channels and floodplain. Large Woody Material structures create velocity breaks and cover for rearing juvenile salmonid and generally add complexity to the system. These trees took on new life, really only possible through SYRCL’s collaborative, “no-waste” efforts with our partners in the Lower Yuba River.

Hansen Brother’s aggregate processing plant is sorting approximately 2,100 tons of material per day. As of August 23, about 20,000 tons of spawning gravel has been stockpiled for riffle augmentation next summer.

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