1. Central Valley Salinity Coalition
Salt and Nitrate Sources Work Plan and Pilot Implementation Study Work Plan
June 17, 2009
Larry Walker Associates
Systech Water Resources, Inc.
Luhdorff & Scalmanini Consulting Engineers
NewFields Agricultural and Environmental Resources, LLC

2. Study Work Plan Outline
Study Objectives and Scope
Pilot Study Areas Descriptions
Study Tools
Study Methods (Area Specific)
Project Deliverables
Project Schedule

3. Proposed Pilot Areas Yolo County -Western Yolo and Lower
Cache-Putah Subbasins - Mix of urban, rural, ag - Mix of SW & GW supplies
Modesto Area - Parts of Modesto, Turlock,
& Delta Mendota Subbasins - Urban with food processing,
rural, ag - Mix of SW & GW supplies
Tule River - Entire Tule Subbasin, also
parts of Tulare Lake and
Kaweah Subbasins
- Mostly ag land, some urban - Mix of SW & GW supplies
3 sections to survey 3

4. Pilot Area Yolo County Western Yolo and Lower Cache-Putah Subbasins
Yolo Co. GW Database: >6,000 wells, >200,000 entries; DWR WQ data for ~ 30 yrs; can query data by depth zone and area
Mix of urban, rural, ag
Mix of SW & GW supplies
Total Area = 183,947 ac
3 sections to survey 4

5. Pilot Areas Modesto Area
Parts of Modesto, Turlock, & Delta Mendota Subbasins
Relates to regional MODFLOW boundary
Urban with food processing, rural, ag
Mix of SW & GW supplies
Rock wells: stormwater recharge
Total Area = 640,524 ac
3 sections to survey 5

6. Pilot Areas Tule River Area
Entire Tule Subbasin, also parts of Tulare Lake and Kaweah Subbasins
WARMF Domain to be added
Mix of urban, rural, ag
Mix of imported SW & local GW supplies
Closed basin; partially salinized
Harter groundwater model
Total Area = 541,580 ac
3 sections to survey 6

7. Study Tools WARMF Model Land Use Data Collection Groundwater Models
MODFLOW model, USGS, Phillips et al. 2007
MODFLOW model, Thomas Harter
Particle tracking MODPATH

8. WARMF Model Overview: Structure
Input and output by point-and-click on a map
Built-in database of meteorology, air/rain chemistry, diversions, point sources, gauging stations, water quality stations
Driven by meteorology, run on daily or hourly time step
Tracks volume of water and mass of chemical constituents
Simulates point and nonpoint sources

9. WARMF Assumptions Does not calculate recharge to deep groundwater
Recharge rate provided by groundwater model
WARMF provides recharge water quality to groundwater model
Groundwater model provides water quality of pumped irrigation water
WARMF applies irrigated water (surface, imported, and GW) and water quality to surface

10. WARMF Model: Static Inputs
Topography Provided by digital elevation models
Land Use DWR land use used for agricultural and urban NLCD used for natural land cover
Soils Porosity, field capacity, layer thickness, hydraulic conductivity are model inputs

11. WARMF Model: Time Series Inputs
Time periods for data collection Sacramento watershed (Yolo): 1921-present San Joaquin (Modesto): 1984 or 1997-present Tule River: 1976-present
Meteorology (CIMIS)
Boundary inflows (USGS, CDEC)
Boundary water quality (many sources)
Diversions (Bureau, USGS, CDEC etc.)
Point Sources (US EPA, local sources)
Fertilizer usage, animal waste

12. WARMF: Irrigation
Seasonal pattern assumed to follow surface water diversion
Annual water applied depends on land use
Surface water is applied toward annual water need
Groundwater makes up the unmet need
Water is applied to the land surface based on the water quality of the sources.

13. Approach to Land Cover (Use) Data
Use available DWR land coverage
Consolidate some land cover classes where WARMF insensitive
Provide appropriate model inputs
Irrigation
Fertilization
Etc.

14. Spatial Downscaling Between WARMF and GW Models
WARMF catchments coarse by default, follow surface water drainage boundaries
Catchments to be split based on land use patterns, groundwater model grids
Yolo County: interact with data only (no model)
Modesto: surface water drainage is important consideration
Tule River: not generally constrained by surface water drainage
Spatial resolution for groundwater models

15. MODPATH: particle tracking
Particle tracking model developed to compute 3D flow paths using output from a MODFLOW (USGS, McDonald and Harbaugh, 1988) groundwater flow model
Can be implemented for either steady state or transient flow fields
Output from MODPATH shows the complete paths of all particles and points of origin (starting points) for all particles discharging to a specific feature or destination points for all particles at a given location.

16. Study Methods Basic Approach (Area Specific) Data Assessment
Data Collection
Mass Balance Analyses
Trend Analyses
Sensitivity Analyses

17. Basic Study Approach Yolo Modesto Tule River
WARMF + Existing Groundwater Data
Modesto
WARMF + MODFLOW (USGS)
Tule River
WARMF + MODFLOW (Harter)

18. Data Assessment: Needs, Availability, Gaps, Sources
Land Use
Irrigation Rates
Fertilization Rates
Point Source Flow and Quality
Surface Water Flow and Quality
Groundwater Pumping and Recharge
Groundwater Quality

19. Data Collection Land Use Irrigation Rates Fertilization Rates
Point Source Flow and Quality
Surface Water Flow and Quality
Groundwater Pumping and Recharge
Groundwater Quality

20. Mass Balance Analysis Ensure complete accounting
WARMF / groundwater interface
Recharge
Pumping
Shallow groundwater / surface water interface
Time periods based on available data at sites
Constituents Considered
Salts (TDS)
Nitrate
Others (e.g. Cl, Na, P)

21. Trend Analyses Historical Present Impact of changing practices
Salts
Nitrate
Present
Impact of changing practices
Distribution and accumulation in groundwater

22. Sensitivity Analyses Land Use
Salts
Nitrate
Hydrological Conditions (wet, dry, normal)
Irrigation Practices (source, method)
Data Accuracy
Prioritizing Data Collection

23. Study Output Groundwater Root zone / surface water
Load entering by recharge
Load leaving by pumping
Shallow & deep groundwater quality
Concentration accumulation
Root zone / surface water
Load from various land uses to surface water
Load from upstream inflows
Point source load
Diverted load / application as irrigation
Transformations / net in-stream loading

24. Project Schedule Draft Work Plan Submittal: July 3, 2009
Final Work Plan Submittal: 1 week after comments
Draft Study Report: November 30, 2009
Final Study Report: December 31, 2009

25. END