A Climate Driven Model of the Water Resources of The Sacramento and San Joaquin Hydrologic Regions: Model Structure and Data Inputs Brian Joyce, Stockholm Environment Institute (530)

Supported by California Department of Water Resources In Collaboration with: –David Yates National Center for Atmospheric Research –David Groves RAND Corporation –Andy Draper Montgomery-Watson-Harza

Sacramento/San Joaquin Valley WEAP Model

Level of Analysis Planning Areas (PA’s) –11 PA’s in Sacramento River Hydrologic Region 4 “Rim” PA’s 7 “Valley” PA’s –10 PA’s in San Joaquin Hydrologic Region 4 “Rim” PA’s 6 “Valley” PA’s –Also include 1 “Valley” PA in the Tulare Lake Hydrologic Region

Watersheds Sacramento Hydrologic Region –4 “Rim” Planning Areas 15 Watersheds San Joaquin Hydrologic Region –4 “Rim” Planning Areas 11 Watersheds North Coast Hydrologic Region –1 “Rim” Detailed Analysis Unit 1 Watershed Pitt River Feather River Yuba River Bear River American River Cosumnes River Merced River Mokelumne River Stanislaus River Tuolumne River Trinity River Stony Creek Cache Creek Putah Creek San Joaquin River Thomes/Elder Creek

500 m Elevation Bands

Two-Bucket Approach

Land Use Classification Hydrology module is applied for each land class within a catchment object Estimates streamflow, as well as snow accumulation/melt

Irrigation and Refuge Demands Sacramento River Hydrologic Region –7 “Valley” PA’s 9 Agricultural Demand Areas 8 Managed Wetlands San Joaquin Hydrologic Region –6 “Valley” PA’s 9 Agricultural Demand Areas 2 Managed Wetlands Tulare Lake Hydrologic Region –1 “Valley” PA 1 Agricultural Demand Area 0 Managed Wetlands

Land Use Based Demands

Irrigated Areas Hydrology module estimates irrigation demands for 20 crop types –Input requirements: Crop schedule, Kc, Rooting depth, Soils data Also, estimates water demand for Outdoor Urban –Input requirements: same as crops

Managed Wetlands Wetlands use same catchment object and hydrology routine as irrigated areas. Also includes “ponding” and “flow through” requirements

Urban Indoor Demands

Urban Indoor Single Family and Multi Family demands estimated as function of water use per household Industrial and Commercial demands estimated as a function of water use per employee

System Operations Reservoir releases and water deliveries “operated” using –Storage Priorities –Storage Buffers –Supply Preferences –Transmission Constraints Priority = 17 Priority = 15 Preference = 3 Preference = 1 Limit = 50% Demand Limit = 40% Demand Limit = 100% Demand

System Operations In-Stream Flow Requirements (IFR) are treated as demand objects. Assigned priorities relative to agricultural and urban water demands. 21 IFR’s in model. Includes AFRP, Delta Outflow, and others

System Operations Sacramento-San Joaquin Delta Water quality considerations: –Use GMOD for Delta salinity standards –Use Kimmerer-Monismith to estimate required net Delta outflow to maintain X2 Delta exports –Constrained by VAMP, E/I Ratio –Target San Luis filling Sep-Mar

Questions Brian Joyce Stockholm Environment Institute (530)