| Agricultural, wetland and urban activities in the San Joaquin River Basin (Basin) discharge high salinity water to the river further degrading water quality. To help alleviate excess salinity, the real-time adaptive wetland water quality management research project was developed. The objective of this project is to improve the water quality in the San Joaquin River (SJR) through better wetland management in the Grassland Water District (GWD). The GWD, located near Los Banos, California is responsible for supplying water and drainage conveyances to 50,000 acres of seasonal wetlands, and hence is a seasonal contributor of salts to the SJR.; These wetlands are managed in a manner that mimics the seasonal "wet/dry" cycle, involving a fall flood-up and a spring draw-down. The draw-downs contain an appreciable salt load, the significance of which is greater during dry years. Coordinating wetland draw-down with periods of higher SJR assimilative capacity can potentially alleviate some of the water quality exceedances currently experienced. Assimilative capacity for salt is the total salt load that the river can receive without exceeding salinity objectives. On average, the GWD contributes 14% of the flow and 16% of the salts in the SJR. Yet during draw-down (February through April) the district contributes 12% of the flow and 18% of the salts in the SJR. The possible water quality benefits of an altered draw-down, however, need to be evaluated together with any impacts an altered wetland draw-down may have on wetland habitat quality.; Ultimately this research developed several decision support tools to aid wetland management operations. These tools include: a real-time water quality monitoring network; a wetland water quality model; and a remote habitat assessment methodology. Individually, these tools can assist wetland managers to make better decisions. However, when used conjunctively, they form a powerful decision support system to improve wetland management and provide feedback for future operations. By understanding the impacts potentially caused by management decisions, wetland managers can adapt future management plans. Yet, for a real-time management approach to improve considerably SJR water quality, a concerted, basin-wide effort is necessary. |
