The following also participated in the A1 Subcommittee Meetings: Baruch BenAmi Netafim USA Casey Cady California Department of Food and Agriculture John Davids Oakdale Irrigation District Hicham Eltal Merced Irrigation District Aaron Fukuda Tulare Irrigation District Bruce Gwynne California Department of Conservation Dan Johnson USDA Gary Kienlen MBK Engineers Tim O’Halloran Yolo County Flood Water Conservation District Todd Manley Glenn-Colusa Irrigation District Anjanette Shadley Martin Western Canal Water District Todd Rinkenberger Netafim USA Spreck Rosekrans Environmental Defense Fund Blake Sanden UC Davis Cooperative Extension Santoyo Friant Water Authority Robert Siegfried Clara Valley Water District Brandon Souza California Agricultural Water Management Council Stacey Sullivan Sustainable Conservation David Zoldoske California Water Institute Table of Contents
Data component Source or options Notes Crop ET and ETAW Regional ET: Option 1: ETo and Kc Option 2: aggregate from more detailed ETo and Kc Option 3: processed satellite imagery - Applied Water To be calculated from ETAW and seasonal efficiencies. [Surface water data from water suppliers]. Private water rights diversions from SWRCB Groundwater measured or estimated, when available CWC §531.10 reporting as it becomes available may GW use is unmeasured or not reported. Improved ways to estimate use are needed. Agronomic Uses Options: reported by suppliers; estimated by DWR DWR will develop and recommend procedures. Environmental Uses Reported by water suppliers. Limited studies and estimates available DWR will develop and recommend procedures (to work with suppliers, California Department of Fish and Game and U.S. Fish and Wildlife Service, CARCD, and other groups to develop estimation procedure). Recoverable Reported from water suppliers DWR may develop and recommend procedures Acronyms: ET- evapotranspiration, ETAW = evapotranspiration of applied water, ETo – reference evapotranspiration, Kc – crop coefficient, SWRCB – State Water Resources Control Board, CARCD – California Association of Resource Conservation Districts
Figure C-4 Schematic diagram of the field scale example C-2 Calculation Examples of Productivity Indicators The purpose of the indicators are: Evaluate crop production (in weight or gross crop revenue) per acre-foot of applied water within a defined scale. Evaluate how production (in weight or gross crop revenue) per acre-feet changed over time within a defined scale. An example of the productivity indicators are calculated for a 73,000 acres county scale in Table C-5. Table C-5 Calculation of productivity as indicators of agricultural water use efficiency Data Element Calculation Result Weight of crop production Example Option 1 – use County Ag Commissioner reports and USDA NASS data, area-weighted for overlying counties Example Option 2 – survey of growers, processers Option 1 = 44.5 tons/acre x 73,000 acres = 3.25 million tons Option 2 = 46.2 tons/acre x 78,200 acres = 3.61 million tons Gross revenue of crop production Example Option 1 – Use Ag Commissioner reports and USDA NASS data, area-weighted for overlying counties Example Option 2 – survey of growers, local processers Option 1 = $56.70 $/ton x 44.5 tons/acre x 73,000 acres = $184.2 million Option 2 = $58.20 $/ton x 46.2 tons/acre x 78,200 acres = $210.3 million County Applied Water provided by DWR from the Plan Update water balance studies Option 1 = 135,050 AF Equations: PAW Calculate range for both methods of estimating production Low: 3.25 MT/135,050 AF = 24 tons/AF High: 3.61 MT/135,050 AF = 26.75 tons/AF VAW Calculate range for both methods of estimating gross revenue of production Low: $184.2 million/135,050 AF = $1,362/AF High: $210.3/135,050 AF = $1,557/AF Table C-6 presents the gross crop revenue or gross value per acre-foot of applied water (VAW) for each of the significant crops or crop groups in Fresno and Colusa counties in California expressed in terms of 2010 dollars per acre-foot of applied water.