Pacific Southwest Research Station

Development of a road cut and fill land use category for the Pollutant Load Reduction Model (PLRM)

Principal Investigators:
Mark Grismer, University of California-Davis
Michael Hogan, Integrated Environmental Restoration Services, Inc.

Proposal [pdf]

Final Report [pdf]

Additional Resources
Road Cut and Fill Slope Sediment Loading Assessment Tool (RCAT) [xlsx]
RCAT User's Guide [pdf]

Please contact Kevin Drake at Integrated Environmental Restoration Services, Inc. with questions regarding the use of RCAT.

Project Summary:
The overall purpose of this project was to develop the data and tools necessary to improve estimates of pollutant loading and load reductions from road cut and fill slopes. The end product of this effort is the Road Cut and Fill Slope Sediment Loading Assessment Tool (RCAT), a simple and repeatable field assessment methodology and spreadsheet tool designed to assist the Lake Tahoe erosion control and stormwater community in characterizing the functional condition of road cut and fill slopes and estimating the associated sediment and fine sediment particle loading from these areas.

Using the most complete set of directly measured erosion data in this region, supplemented by additional targeted rainfall simulation under this project, the project team developed the runoff pollutant concentration values needed to support a road cut and fill slope land use category. In collaboration with agency personnel, the team also developed an assessment methodology for directly measuring several key erosion parameters in the field.

After several discussions with the developers of the Pollutant Load Reduction Model (PLRM), it became clear that formal integration of the road cut and fill land use into PLRM would require a new module that was beyond the scope of this project. Therefore, we a simple, stand-alone spreadsheet tool – the RCAT – was developed. Regulators and project implementers can use the tool to estimate the sediment loading potential of cut and fill slopes before and after project implementation. The data outputs from this tool (sediment loads and runoff volumes) can be used in conjunction with PLRM or separately.