Figure 31. Gravel bar volume changes during 2001–09 at instream gravel mining sites along the South Umpqua River, Oregon. Refer to table 8 for data sources and values underlying this figure. For sites with missing surveys, cumulative totals assume no net change for the period of missing data. Mean monthly and annual (water year) peak flows are from the USGS data for streamflow-gaging station on South Umpqua River near Brockway (station 14312000).

First posted September 29, 2011