**3. Real-Time Salinity Management**

The USBR provides water to west-side agricultural and wetland resource contractors via the Delta-Mendota Canal (DMC). The USBR's water rights under which the USBR delivers water to the SJR Basin were amended to require that the USBR meet the 1995 Bay Delta Plan Salinity objectives at Vernalis, which are equivalent to the numeric targets established by the salinity TMDL [13]. Upstream salinity objectives at the Crows Landing Bridge compliance monitoring site was ratified in 2017 to protect riparian diverters downstream of Crows Landing and upstream of the Vernalis compliance monitoring site [21]. The control program requires the USBR to meet DMC salt load allocations or provide dilution flows to create additional assimilative capacity for salt in the LSJR equivalent to DMC salt loads in excess of their allocation. Thec program includes an innovative provision that provides relief from the restrictive salinity load restrictions imposed by the salinity TMDL and codified in the Basin Water Quality Control Plan. This provision states that "Participation in a Regional Board approved real-time management program (RTMP) and attainment of salinity and boron water quality objectives will constitute compliance with this control program" [21]. Participation in the RTMP was designed to promote cooperation and data sharing between entities, effectively replacing a costly salt load-based regulatory program with a more cost-effective, stakeholder-driven program that permitted full use of the river's assimilative capacity for salt [14,15,21]. Participation in the RTMP also included the development and use of a water quality forecasting model to provide stakeholder decision support and allow stakeholders sufficient time to address anticipated violations of the 30 day running average EC at compliance monitoring stations along the SJR [14]. The WARMF model was chosen for this task [22–24]. Compliance became the collective responsibility of SJRB stakeholders including the USBR.

The RTMP strategy increases potential management flexibility for agricultural, wetland and municipal dischargers to the SJR and provides an opportunity to maximize salt load export from the basin without exceeding environmental objectives. However, it assumes a level of coordination and cooperation amongst stakeholders that does not currently exist. The core elements of this program have led to: (a) the development of a basin-scale, sensor network to collect real-time monitoring of flow and salinity data; (b) an information dissemination system for effective sharing of data among basin stakeholders; (c) a need for continual calibration of the WARMF hydrology and salinity model of in the SJR and its contributing watersheds to improve the accuracy of forecasting and daily assessment of river assimilative capacity; (d) the creation and funding of stakeholder institutional entities responsible for coordinating salinity management actions and ensuring compliance with SJR salinity objectives; and € continued oversight and sanction of the CVRWQCB [14–16].
