Erosion Control BMP Studies

This study evaluated permanent soil stabilization techniques for Caltrans rights-of-way. Both small-scale and field-scale tests were performed. Small-scale tests were performed for 5 soil roughness techniques, 15 soil stabilization methods (e.g., straw blanket, bonded fiber matrix, wood fiber matrix, etc.), and various vegetation cover and establishment combinations. Field-scale tests were performed for various combinations of the techniques assessed in the small-scale tests.

OWP Tasks

• Technical Assistance and Planning

Report/Study Link:
Caltrans District 7 Erosion Control Pilot Study
OWP Contacts: Kevin Murphy

This study was conducted to provide a comprehensive, data-rich, and timely review of common Caltrans erosion control problem sites throughout California. This effort focused on extreme variability in climate, soils, plant growth, and elevation; unsuccessful erosion control practices; control standards; and historical information.

Report/Study Link:
Caltrans Temporary Soil Non-Vegetative Stabilization Study
OWP Contacts: Kevin Murphy

This study assessed the performance of seven hydraulically applied erosion control products applied to soil plots at the San Diego State University Soil Erosion Research Laboratory (SDSU/SERL). Each hydraulic application was subjected to two sequential simulated storm events, each representing a 10-year storm as predicted for the Los Angeles Basin. The hydraulic soil stabilizers were compared using a variety of criteria, including soil loss, runoff, and 24 water quality measurements

OWP Tasks

• Technical Assistance and Planning

Report/Study Link:
Caltrans Hydraulic Application Study
OWP Contacts: Kevin Murphy

This study developed guidance for effective establishment and maintenance of erosion control vegetation for rapid short-term growth and for long-term establishment. Proper seed selection, time of year for seeding, appropriate methods of hydroseeding, plant establishment criteria for erosion control and soil stabilization, and site maintenance needs throughout the lifecycle of the plants were considered. Rainfall simulators were used to perform numerous small-scale studies.

OWP Tasks

• Technical Assistance and Planning

Report/Study Link:
Caltrans Vegetation Establishment and Maintenance Study
OWP Contacts: Kevin Murphy

This report consolidated information on developed technologies that could be applied as part of the Caltrans Statewide Storm Water Management Plan (SWMP). Available information was summarized regarding design, specifications, application, effectiveness, relative cost, and issues relevant to Caltrans facilities. Forty practices and approximately 200 products were identified for potential use and possible field or laboratory pilots as an initial step in the process of identification and selection of new BMPs.

OWP Tasks

• Technical Assistance and Planning

Report/Study Link:
Caltrans Erosion Control New Technology Review Project
OWP Contacts: Kevin Murphy

This effort involved a roadside erosion control and management experiment to statistically test for significant differences in water quality and vegetation establishment among existing Caltrans soil stabilization specifications to better reduce runoff and sediment transport. The study compared the effects of different compost treatments on water quality and the establishment of native shrubs. The experiment assessed the establishment of four California native shrub species under different seed bed treatments, with variations in type, application method, and depth of compost layer.

OWP Tasks

• Technical Assistance and Planning

Report/Study Link:
Caltrans Native Shrub Germination Relative to Compost Type, Application Method, and Layer Depth
OWP Contacts: Kevin Murphy

This effort consisted of two main experiments. The first compared the effects of physical erosion control treatments (soil roughening, jute netting, jute netting over compost, straw crimped into compost, and straw crimped into soil) on clay loam and fine sandy loam topsoils with existing soil seedbanks. During the second experiment, fiber and compost hydroseed mix was applied at various rates. The correlation between application rates and germination of existing soil seedbanks and germination of native seed was measured.

OWP Tasks

• Technical Assistance and Planning

Report/Study Link:
Caltrans Performance of Erosion Control Treatments on Reapplied Topsoil
OWP Contacts: Kevin Murphy

This study involved developing a comprehensive strategy to evaluate the effectiveness of different non-vegetative erosion control products as influenced by site characteristics in arid regions of California. Five treatments (Poly Pavement, Rock Slope Protection, Soil Cement, Soil Seal, and Soil Tac) were tested at three locations. The experimental design was set up to investigate treatment performance over time, treatment performance versus no erosion control and versus other treatments, and environmental factors affecting performance. Total sediment yield and runoff volume data were collected and analyzed using time series analysis, multiple regression analysis, and analysis of variance (ANOVA) to evaluate product effectiveness.

OWP Tasks

• Technical Assistance and Planning
• Reviewed Designs of Monitoring Systems
• Provided Monitoring Assistance
• Reviewed Data Assessment and Reporting

Report/Study Link:
Caltrans Arid Region Non-Vegetative Erosion Control
OWP Contacts: Christian Carleton

This evaluation included experiments to identify and select plant species that demonstrate initial fast growth, provide potential long-term erosion control, and ultimately improve water quality. Experiments were conducted under a variety of rainfall regimes and erosion control treatments. The plants examined in these studies included both native and non-native naturalized species. Additional information, including rainfall simulator design, heavy metal transport, and germination rates, was gathered in small-scale studies.

OWP Tasks

• Technical Assistance and Planning

Report/Study Link:
Caltrans Evaluating Hydroseeding and Plug Planting Techniques
OWP Contacts: Kevin Murphy

This work provided a comprehensive, data-rich, and timely review of common Caltrans erosion control problem sites. Initial work involved developing a detailed, user-friendly, Excel-based site evaluation program designated as the Highway Erosion Assessment Tool (HEAT). This comprehensive field review provided recommendations for improving erosion control practices on various sites throughout California.

OWP Tasks

• Technical Assistance and Planning

Report/Study Link:
Caltrans Statewide Erosion Control Review
OWP Contacts: Kevin Murphy

This work provided a comprehensive, data-rich, and timely review of common Caltrans erosion control problem sites. Initial work involved developing a detailed, user-friendly, Excel-based site evaluation program designated as the Highway Erosion Assessment Tool (HEAT). This comprehensive field review provided recommendations for improving erosion control practices on various sites throughout California.

OWP Tasks

• Technical Assistance and Planning

Report/Study Link:
Caltrans Vegetation Establishment for Erosion Control Under Simulated Rainfall
OWP Contacts: Kevin Murphy