Following is the appearance of the Best Management Practices (BMP’s) tab of the Catchment Coefficients dialog:
The name of this catchment is shown in the caption of the dialog box. The image in the lower left corner is a copy of the map showing the catchment(s) being edited. When each tab is selected, a new group of coefficients appears.
Following is a description of the parameters associated with BMP’s. Refer to the main Catchment Coefficients page for information on other categories of coefficients. To save the changes made when closing this dialog, click OK. To ignore changes, click Cancel.
The Livestock Exclusion spreadsheet is used to indicate the portion of land application loading which is put directly into the stream instead of onto the land surface. For each land use, enter the portion of loading directly to the stream, which typically results from livestock not being excluded.
Percent Buffered is the percentage of stream length adjacent to sediment yielding lands which has a buffer zone. (0 – 100%)
Width is the average width of the buffer zone when it exists (>0 m)
Slope is the average slope of the buffer zone when it exists (>0, unitless)
Roughness is the Manning’s n value for overland flow within the buffer zone (0.05 – 0.4, empirical units)
Frequency is the time period between street sweeping passes (> 0 days; 0 = no street sweeping)
Efficiency is the portion of deposited material removed in one street sweeping pass (< 100%)
Impervious Routing is the percent of impervious surface within the catchment that is routed directly to a stormwater detention pond
Volume is the volume of all detention ponds in the catchment
When the Apply Changes To Selected Catchments button is checked, changes made to the coefficients of the catchment being edited will be made to all selected catchments. When the Apply Changes To All Catchments button is checked, changes made to the coefficients of the catchment being edited will be made to all catchments.