**8. Stakeholder Response and Coordination**

As previously noted, this event has provided the USBR with an opportunity to demonstrate the agency's commitment to its obligations under the MAA, reminded stakeholders of their role in the real-time program and exposed deficiencies in real-time response to periods of water quality exceedance. During the second week of February, when it became clear through the use of the forecast models that the salinity at both Vernalis and Crows Landing stations was trending towards potential exceedance of the 30 day running average EC stakeholders were notified directly. The likely date of exceedance was estimated to be March 5 from WARMF and Regression model forecasts made on 23 February 2021. In order to provide stakeholders adequate time to perform remedial actions, we decided to directly engage with stakeholders in the SJRB rather than rely on the USBR's normal weekly posting of flow, EC and 30 day running average EC at the three compliance monitoring

stations. Communication with stakeholders was primarily by e-mail to east- and west-side agricultural stakeholder coalitions, directly impacted water district, and representatives of the private, state and federal wetland entities. the San Joaquin Valley Drainage Authority, Grassland Water District, Los Banos Wildlife Management Area, Patterson and West Stanislaus Irrigation Districts, on the east-side Modesto and Turlock irrigation districts and the East SJR Water Quality Coalition. A similar e-mail was sent to the Regional Water Quality Control Board, the basin regulator, that has the power to set fines for water quality objective exceedances.

In retrospect, the timing of the stakeholder outreach was timely and prescient. Although anticipated, programmatic fish migration flows from east-side reservoirs, that started in mid-April, were able to drive down the EC at Vernalis below the 700 μS/cm limit that came into effect on April 30. The Merced River is the only tributary to the SJR upstream of Crows landing and supplemental flows for fish migration were insufficient to prevent the EC at Crows landing from exceeding objectives. During the period of exceedance at the Crows Landing compliance monitoring, there were opportunities to address the excess salt loading to the SJR. During the initial period of exceedance, raising the board elevation at the San Luis Drain outlet (a previously used conveyance facility that carries only subsurface agricultural drainage) and storing drainage return flows in the drain for later release would have reduced salt loading by 100 tons (91 tonnes) per day and eliminated the deficit in SLAC. Most drainage return flows into the drain are from seepage from adjacent agricultural land and wetland and with an average salinity of 2500 μS/cm. However, after the first days of exceedance, the daily EC remained elevated above 1550 μS/cm and the 30 day running average SLAC deficit climbed to a steady state load of approximately negative 1000 tons (907 tonnes) per day.

The exceedance of the Crows Landing EC objective occurred during the wetland drawdown period when the Grassland Water District and adjacent State and Federal refuges are draining ponded surface water to allow germination of swamp timothy, smartweed and water grass food crops that serve overwintering waterfowl. Since the timing of this drawdown is critical for swamp timothy production and the waterfowl that prefer this food source, asking wetlands to curtail drawdown during this period was viewed as unrealistic by wetland resource managers.

Procurement of additional dilution flow from the Merced Irrigation District was also unrealistic given the prevailing drought conditions and anticipated water shortages during the summer of 2021. In addition, some entity would have had to foot the bill for procurement of any additional supply if supply were available.

The Regional Board has taken a "wait and see" approach to this first test of the real-time water quality management system and the newly promulgated upstream EC objectives at Crows Landing and Maze Road compliance monitoring stations. There has been no discussion of fines or allocation of penalties across subareas contributing salt load to the SJR from the Regional Board. There is also the fact to consider that riparian diverters along the northwest-side subarea is the river reach that the upstream objective was promulgated to protect. Fining stakeholders who are being harmed by the elevated EC along this reach of the SJR would be problematic.

At the time of writing, the severe drought conditions in the basin have reduced forecasted flow for 10 June 2021 at the Crows landing compliance monitoring station to under 100 cfs and daily EC is once again over the 1550 threshold EC. The 30 day running average EC is climbing once again and may remain above the objective for the remainder of the irrigation season while drought mitigation actions are in force.
