Erosion and sediment control on construction sites is an increasingly important aspect of project management. Most erosion control practices which are currently implemented as part of a sediment and erosion control plan are intended to prevent erosion through diversions, mulching, and seeding. Sediment control is designed to slow runoff to allow entrained soil to settle. However, projects located adjacent to streams with minimal buffers are particularly challenged because there is little land available to construct traditional controls such as sediment traps and basins. This is further exacerbated by the steeper slopes found along many mountain streams. These are particularly valued for their water quality and stream habitat, which can both be impacted by disturbances in the watershed. This combination may be effective in retaining a large portion of potential sediment within the construction site, but runoff is likely to remain highly turbid. The suspended solids concentration in the discharge water has adverse impacts on the receiving waters and may result in complaints from the public.
Over the course of the project, we will establish monitoring of erosion and sediment control at three sites where road improvements are being implemented. We will attempt to find sites widely distributed in the mountain region. At each site, we will:
- Conduct detailed monitoring of erosion and sediment control effectiveness under typical and modified systems on road improvement projects adjacent to mountain streams.Compare a variety of erosion control systems for effectiveness, including combinations of standard straw, polyacrylamide, rolled erosion control products, composts, and manufactured matrix hydromulching.Install, evaluate, and improve (as needed) systems to increase sediment and turbidity control in standard and modified ditches, traps and basins.
