Sacramento Bar – after high flows

Posted on Wednesday, February 8th, 2017

With the river heading back up to 30,000 cfs, it seemed appropriate to pause and take a quick look at what has shifted since the fall. The first picture is pre-project (2015, Google Earth) and the river is flowing right to left around the large gravel bar.

This photo is shortly after construction with the river flowing at 1,600 cfs. We processed about 50,000 cubic yards of material to create the side channel and lower the floodplain habitat so that it inundates more frequently. About half of the processed material went into the main channel to create spawning habitat (you can see it as the lighter colored in river area). These projects are designed to provide maximum habitat at 1,750 cfs but remain functional at higher flows.

Flow at 1600 cfs

The aerial below shows Sacramento Bar with 20,000 cfs flowing down the river. We understand that these projects are never permanent, which is why we aim to do one each year without and end date.

Sacramento Bar 20,000 cfs

This image shows the river flowing at 8,000 cfs looking downstream after the 60,000 cfs flood flow. You can see gravel movement on the bar and upper portion of the side channel. We’ve noticed some movement of woody material, some has migrated off-site and some has been replaced.

8,000 cfs flowing downstream.

 

With the flows still changing, we do not plan to do any significant monitoring until flood season passes and there is more stability. We are hoping to collaborate with SAFCA, USFWS, and Reclamation to update the digital elevation model to accurately model the river from nimbus to the mouth, and levee to levee.

 

PostedWednesday, February 8th, 2017