Impacts of sediment removal project

Abstract

In August 2019, Sonoma Water dug tons of sediment out of the Laguna de Santa Rosa where it passes under Stony Point Road in Rohnert Park as part of their Flood Control Maintenance Program. 

This part of the Laguna had become progressively shallower over time as nutrient-rich sediment that had been washed downstream slowed down and settled out. The problem with it being wide, shallow, and sunny is that the invasive weed Ludwigia thrives in those conditions and has completely overgrown the Laguna in this area. As part of the sediment removal project, a narrow, deeper, more shaded side was carved out within the channel.

We have been characterizing five transects at that site before, during, and after the sediment was dug out. Each time, we have measured channel topography, water depth, amount of canopy cover, and percentage of Ludwigia in order to determine if the new deeper channel design is effective at discouraging Ludwigia growth.

Results

 
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Monitoring Impacts of a Sediment Removal Project in the Laguna de Santa Rosa

poster Ancheta, Barragan-Franco, Bauer, Bowling, Cappellano, Carter, Duke, Ellingboe, Elson, Gaughran, Hallford, Hoover, Jackson, Landau, Lillis, Mason, Mcjunkins, Meininger, Moquin, Nielsen, O'Brien, Perez, Peters, Ramirez Padilla, Santos, Schlemer, Scott, Simonds, Taylor, Wilson

 

Keywords:  Laguna de Santa Rosa, river, water depth, creek morphology, canopy cover, plant type, transects, Guilford