These spreadsheets contain all data, sources and methods used for Technical Appendix B of the report A New Approach to Accounting for Environmental Water: Insights from the Sacramento‒San Joaquin Delta (2017). The Delta is operated according to regulations that assign water flowing into and out of the Delta to various purposes. These spreadsheets estimate the outflow needed to meet these regulations, including protection of water quality for the following: in-Delta agricultural and municipal and industrial (M&I) uses and Delta exports (collectively referred to here as “system water”); protection of water quality and flows for ecological uses (“ecosystem water”); diverted for in-Delta and export uses (“water diversions”), and water that exceeds these demands and regulatory requirements (“uncaptured water”). These data cover the period 1980‒2016, a time during which significant regulatory changes affected the apportionment of Delta inflows.
The file contains the description of the variables, and four spreadsheets with the Delta Water Accounting datasets at different time scales—daily, monthly, calendar year, and water year. It also includes a succinct description of the methods and model used to obtain water flows from salinity standards in the Delta (G-Model).
These data were obtained following the description included in the Technical Appendix B, using the following input sources:
- DAYFLOW: An estimate of daily average Delta outflow. Department of Water Resources.
- California Data Exchange Center (CDEC). Department of Water Resources.
- Delta Islands Consumptive Use Model (DICU). For DICU documentation:
- “Estimation of Delta Island Diversions and Return Flows.” California Department of Water Resources, Division of Planning. February 1995.
- G-Model: Used to obtain water flows from salinity standards in the Delta. For G-model documentation:
- Denton, R. “Accounting for Antecedent Conditions in Seawater Intrusion Modeling Applications for the San Francisco Bay–Delta.” Hydraulic Engineering 93 (1): 448‒453. 1993.
- Denton, R. “Antecedent Flow‒Salinity Relations: Application to Delta Planning Models.” Contra Costa Water District. December 1993.
- Sullivan, G. D., and R. Denton. “Report on Clean Water Act X2 Water Quality Standards.” Contra Costa Water District. February 1994.
- For carriage water documentation:
- Denton, R. “Refining CCWD’s Salinity-Outflow Model.” Contra Costa Water District. April 25, 2006.
- State Water Project Annual Report of Operations. Department of Water Resources.
For a detailed analysis of this data see Technical Appendix B: Water Assigned to Meeting Environmental Standards in the Delta from 1980‒2016
For questions concerning this dataset, please contact Greg Gartrell.