Hydromodification, the response of streams to changes in flow and sediment input, is a focus of scientific investigation and emerging regulation. Many management schemes traditionally have used a “one-size-fits-all” approach to managing hydromodification effects, whereby a single criterion is applied to all streams within a given area. However, factors such as dominant bed material, channel planform, vegetation, and existing infrastructure can influence the rate and manner in which streams respond to changes in flow and sediment. Consideration of these differences in management programs requires a tool to rate stream reaches in terms of their relative susceptibility to hydromodification effects.
The tool builds on studies done in other regions to provide a means to rank southern California stream reaches in terms of their relative likelihood of response to hydromodification. The screening tool consists of two elements: 1) a GIS-based landscape-scale analysis of relative sediment yield to stream channels, and 2) field-based assessment of channel condition. The data entry spreadsheet is designed to support the field-based assessment.
This spreadsheet is intended to support use of the field screening tool for channel susceptibility detailed in SCCWRP Technical Report #606. The data entry fields in the spreadsheet mirror those in the field guide. Users are encouraged to download the tool and use it to enter the raw data they collect in the field. The spreadsheet will automatically calculate values and scores using the formulas and decision trees presented in the field guide. Once a field evaluation is completed, users are encouraged to email a copy of the spreadsheet to SCCWRP, care of Eric Stein, for inclusion into the regional database.
This tool was developed with Colorado State University, Fort Collins, and the Southern California Stormwater Monitoring Coalition.
For more information on the hydromodification susceptibility screening tool, contact Eric Stein.