DWR – It just started raining and you already ramped up Delta exports again despite all the salt water and the risks to endangered Winter Run salmon and Delta Smelt. I recently suggested “Whoa,”1 as did Smelt Working Group. At least wait until the runoff from the storm hits the Delta.
The Smelt Working Group concluded on December 30: “The Working Group reviewed Delta Smelt distribution conditions. The working group concluded that entrainment risk has increased. This is based on fish distribution combined with increased water exports, but the group provided no recommendation for a change in water export reduction for either Delta Smelt or Longfin Smelt. This decision was based on the projected decrease in OMR flows from -5600cfs today to -2100cfs on Monday, 1/4. The group will be monitoring conditions closely over the next several days.” But no sooner had January 4 arrived than exports jumped sharply to even higher than the late December level (Figure 1), despite all the early warning signals brought up by the Working Group2.
Figure 1. State Water Project Delta exports at Clifton Court Forebay in past month.
The higher exports, in combination with spring tides, have pushed the Low Salinity Zone further east and south into the Delta (Figure 2). (Note: the ten-day charts readily depict recent increased salinity.)
Figure 2. Aerial photo with salinity levels (charts of EC), freshwater inflow (blue arrow), negative net inflows of brackish water (red arrows), and route taken by juvenile Winter Run salmon (yellow arrows). Clifton Court at bottom center.
Perhaps more ominous is the increase in salvage of Winter Run salmon (Figures 3 and 4). Twenty-seven were salvaged on 1/6. Given poor salvage efficiency (near 10 % in forebay alone) and the likely presence of many Winter Run trapped in the central and south Delta, as well as the desperate state of the Winter Run population, this is no time to be increasing exports. Where is the Salmon Working Group? This is serious “take”; authorized or not, NMFS should be doing something.
Figure 3. Salvage of Winter Run at south Delta fish facilities. (Missing from this graph is 1/6 salvage that is depicted in Figure 4.) Source: http://www.dfg.ca.gov/delta/apps/salvage/SalvageExportChart.aspx?Species=1&SampleDate=1%2f2%2f2016&Facility=1
Figure 4. Salvage of Winter Run salmon at south Delta fish facilities 1/1-1/6 2016. Source: http://www.usbr.gov/mp/cvo/vungvari/salmondly.pdf