Agricultural sensitivityto climate change and water resources interactions in the San Joaquin...
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Transcript of Agricultural sensitivityto climate change and water resources interactions in the San Joaquin...
05/01/2023 1
Agricultural sensitivityto climate change and water
resources interactions in the San Joaquin Valley, Calif. and
system resilience offered by adaptation strategies
Presenter:Philip Bachand
Bachand & Associates530-758-1336
05/01/2023 2
Critically Overdrafted Groundwater Basins, 2016
Management Plan
Climate Change
Local Adaptation
Regional Adaptation
Reservoir Management
Rain / Snow
Runoff
Temp / Precipitation / ET / CO2
Land UseGroundwater Supplies
Surface Water
SuppliesWater Transfers
Conjunctive Use
Recharge and Withdrawals
ISNOBAL
CalSim
C2VSIM
WUE
NUE
CO2 fertilization
Ag Literature and Databases
Cultural Practices
Crop Yield
Water Resources Water Quality
Outcomes
Anthropogenic Feedback Mechanisms
Estimated NPV: Total and by groups and subwatersheds
Economic Model
WARMF
Land Use
Precip
SJV Stream flow and quality
Irrigation
Fertilization
Tetra TechSujoy Roy, pH.D., LeadTASK 3
Tetra Tech and UC Davis LAWRPhilip Bachand, pH.D., LeadTASK 5
UC Davis LAWR and Tetra TechDr. Lucas Silva, pH.D. Lead
TASK 1
Systech and Tetra Tech
Joel Herr, LeadTASK 3
UC Merced and Tetra TechProf Rob Rice, pH.D. LeadTASK 2
UCD AREDr Leslie Butler, Lead
TASK 4
05/01/2023 4
Key questions identified in the proposal• What magnitude of change is required in water management to
address changes in precipitation timing, frequency and type, and in snowpack water storage?
• What cropping strategies are likely to sustainably mitigate climate change pressures and how will those affect crop distribution in the SJV?
• How sensitive, robust and resilient are these cropping strategies to the evolving climate change / water paradigm?
• What are the economics behind adaptation strategies at the local and regional scale?
05/01/2023 5
Reservoir Operation - Today
Surface Water Supply Demand
Oct Nov Dec Jan Feb Mar Apr May Jun July Aug Sep
Reservoirs
• Surface Water Supply• From Sierra runoff
• Demand• Agricultural demand dominates
demand
• Reservoirs• Managed to mitigate floods and
meet demand curve
05/01/2023 6
Reservoir Operation - Today
Surface Water Supply
Oct Nov Dec Jan Feb Mar Apr May Jun July Aug Sep
Reservoirs
• Surface Water Supply• From Sierra runoff
• Demand• Agricultural demand dominates
demand
• Reservoirs• Managed to mitigate floods and
meet demand curve
Groundwater
Demand
05/01/2023 7
Watershed of the Sacramento-San
Joaquin Delta and Regions that Use
Delta WaterCVP Target--• Serves 2M Ac Irr. Ag • Delivers 7M Ac-ft
• 70% to Ag• 9% to Urban• 11% to wildlife
State Target --• Serves 0.75M Ac Irr. Ag • Delivers 3M Ac-ft
• 30% to Ag• 70% to Urban
Total SWP Annual Delivery (1000 Ac-FT), DWR 2015
05/01/2023 8
2014 Sustainable Groundwater Management Act (SGMA)
Sustainable Yields & Undesirable Results• “Sustainable yield,” according to the SGMA, means the maximum quantity of water
– calculated over a base period representative of long-term conditions in the basin that can be withdrawn annually from a groundwater supply without causing an undesirable result.
• Undesirable Results: Chronic lowering of groundwater levels (excluding reductions in groundwater levels during
drought if offset during other periods) Significant and unreasonable reductions in groundwater storage; …. seawater intrusion; …. degradation of water quality; …. land subsidence; and Surface water depletions that have significant and unreasonable adverse impacts on
beneficial uses.
05/01/2023 9
Conveyance and Exports in California’s Water Budget
1873 TODAY
Sacramento River
Sacramento River
San Joauqin River
San Joauqin River
CVP (Federal) and SWP (State)Diversions
05/01/2023 10
The San Joaquin Water Budget
Surface Transports
Surface Storage Use
Loss
F=
• Precipitation(t)= F(Climate = F(Climate Change)
• Infiltration(t) = F(Soils, Geology, etc…)
• Evapotranspiration(t) = F(Climate = F(Climate Change))
• Other(t)• Delta Flows and Mgmt
• Capacity(t)• Conveyance(t)• Management(t)• Inefficiencies(t)• Costs(t)
F=
• Demand of Sectors(t)= F[ ]
• Recycling(t)• Reuse(t)• Conservation• Hard Needs• Soft Needs =
F(Wealth, etc…)• Costs(t)
F=
(t)(t)
(t)
Groundwater Supply (? MAF Overdraft
Annually) (t)
Sierra Runoff
(t)
(t)
05/01/2023 11
Complying with the Biological Opinions to comply with Endangered Species Act
State and/or Federal Listing Status of Native Fish SpeciesCommon Name Scientific Name Listing StatusDelta smelt Hypomesus transpacificus FT, SElongfin smelt Spirinchus thaleichthys FC, STChinook salmon, Central Valley spring-run ESU
Onorhynchus tshawytscha FT, ST
Chinook salmon, Sacramento River winter-run ESU
Onorhynchus tshawytscha FE, SE
steelhead, Central Valley DPS
Onorhynchus mykiss FT
green sturgeon DPS Acipenser medirostris FT
F = Federally-listed under ESA | E = Endangered | C = Candidate Species for Listing| ESU = Evolutionary Significant Unit | S = State-listed under CESA | T = Threatened |DPS = Distinct Population Segment
The CVP/SWP operations are informed through a structured decision making
process designed to reduce the adverse effects on federally and state listed fish
species.
05/01/2023 12
SGMA Supply Augmentation – Water Available• Potential water sources
• Surface water• Recycled water• Conserved water• Brackish or saline water, Desalination• Transferred water• Other
• Aquifer replenishment• In lieu recharge• Direct recharge
• Uncertainties• Climate change• Institutional / regulatory
constraints• Regional and local challenges
and implementation strategies
• State Water Project and Central Valley Project
• System reoperation
05/01/2023 13
Future Opportunities and Considerations towards Supply Augmentation and Demand Reduction
• Sustainable Yield (SGMA)• WUE and NUE (Demand; Agriculture; Horwath, et al)• Estimating regional overdraft from cropping data (Demand; Agriculture; Bachand)
• Sierra Water Deliveries• Sierra Nevada Runoff Timing and its Variance (Supply; Water; Rice et al)• Sierra Nevada Runoff Annual Volume Reductions (Supply, Water; Rice et al)
• Augmenting Water Supplies• On-Farm Recharge and Agricultural Water Banking (Supply; Water; Bachand et al)• Reservoir and Water System Re-operation (Supply; Water, Bachand, Sujoy, et al)• Within and Outside Water Transfers (Supply; Water; Roy, Herr et al)
• Delta Management under Climate Change (Supply; Water, Roy, Herr et al)
• Economics• Land Fallowing and Retirement (Demand; Agriculture; Butler et al.)• Water Markets (Supply; Water; Butler et al.)
05/01/2023 14
NASSDatabase
*5
*
*
**WARMF Estimates
*
*
Silva, Maxwell, Horwath et al, 2016
Task 1. Quantify relationships between crop yields, farm practices, and possible environmental impacts.
Key Issue. Viability of agricultural efficiency depend upon crop response to changes in climate and atmospheric composition.
Specifically we want to know:
• What will be the net impact of climate change and rising CO2 on crop WUE and NUE?
• How will these changes affect yield quantity and quality of different crops?
• How will these impacts change water, carbon and nutrient cycles at the regional level?
Silva, Maxwell, Horwath et al, 2016
05/01/2023 16
Changes in irrigated land inputs from 2007 – 2012 (2012 USDA NASS Census Report)
Characteristics Units2012 2007 2012:2007 2012 2007 2012:2007
Land in farms acres 16,039,761 16,231,930 99% 9,529,240 9,132,765 104%Irrigated land acres 7,861,964 8,016,159 98% 167,332 0%Market value of agricultural products sold $1,000
37,327,971 29,586,599 126%5,299,501 4,298,465
123%
Total farm production expenses $1,000 30,233,225 23,015,562 131% 5222442 3,947,079 132%Fertilizer, lime, and soil conditioners purchased $1,000
1,793,731 1,294,928 139%12,331 19,247
64%
chemicals purchased $1,000 2,171,784 1,347,595 161% 18,889 21,537 88%
Gasoline, fuels, and oils purchased $1,000 1,402,954 998,021 141%
22,203 26,29684%
Utilities $1,000 1,571,566 1,132,624 139% 112,777 98,923 114%
Irrigated Farms, Any land irrigated Nonirrigated Farms
Understanding current water demand and trends based as cultural practices are changing
Task 1. Quantify relationships between crop yields, farm practices, and possible environmental impacts.
Key Issue. Changing cultural and irrigation practices have affected crop inputs, per acre efficiencies and per acre yields.Specifically we want to know:
• What effects do the changing practices have on crop distribution and regional inputs, including water demand?
• How are these factors affecting surface and ground- water demand?
Task 1 – Upcoming Steps• Viability of agricultural efficiency depend upon crop response to
changes in climate and atmospheric composition.• Silva, Maxwell, Horwath et al are assessing these effects.
• Assessing CO2 effects on WUE and NUE using available datasets and modeling based upon plant physiology.
• Inputting data into water quality model (ie. WARMF)
• The effects of changing agricultural practices on local and regional water use
• Bachand, Silva et al• Using available NASS, DWR and other data sets to assess how changes in
agriculture have affects water use and groundwater pumping
05/01/2023 18
05/01/2023 19
Future Opportunities and Considerations towards Supply Augmentation and Demand Reduction
• Sustainable Yield (SGMA)• WUE and NUE (Demand; Agriculture; Horwath, et al)• Estimating regional overdraft from cropping data (Demand; Agriculture; Bachand)
• Sierra Water Deliveries• Sierra Nevada Runoff Timing and its Variance (Supply; Water; Rice et al)• Sierra Nevada Runoff Annual Volume Reductions (Supply, Water; Rice et al)
• Augmenting Water Supplies• On-Farm Recharge and Agricultural Water Banking (Supply; Water; Bachand et al)• Reservoir and Water System Re-operation (Supply; Water, Bachand, Sujoy, et al)• Within and Outside Water Transfers (Supply; Water; Roy, Herr et al)
• Delta Management under Climate Change (Supply; Water, Roy, Herr et al)
• Economics• Land Fallowing and Retirement (Demand; Agriculture; Butler et al.)• Water Markets (Supply; Water; Butler et al.)
05/01/2023 20
On-Farm Flood CaptureDefinition and Vision
• Available = Physical, Legal
• Leveraging Private Lands
• Dual Use Farm and Flood
• Design into Farm Management
• Leveraging Community Resources
Capturing Available Flood Flows onto Farm Lands for Groundwater Recharge and to Mitigate Downstream Flood Risks
05/01/2023 21
Flood Flow Thru the James Bypass
Winter Flooding of Row Crop Fields
05/01/2023 22
Acreage needed to offset 1M ac-ft overdraft for different Periods and Rates of Infiltration
2 4 6 80
200,000
400,000
600,000
800,000
1,000,000
1,200,000
1,400,000
1,600,000
4812
Infiltration Rates (in/d)
Period (weeks)
Acre
s Req
uire
d
05/01/2023 23
Regional Considerations for On-Farm Flood Recharge
Opportunities for Recharge due to high precipitation
Reservoir / Water System Reoperation
Water Transfer Opportunities
Dahlke et al, 2016
Yield Potential
05/01/2023 24
Summary To Date• Project ranges across water, agriculture, economics and climate change• California’s regulatory climate (e.g. SGMA) is a main driver for potential solutions• Modeling tools that are being used to assess opportunities and scenarios include CA hydrologic
models, agricultural datasets and public databases, runoff models and economic models including the Statewide Agricultural Production Model.
• Collaborators from public and private groups• Scenarios being defined in conversations with stakeholders and in consideration of climate
changes and California’s regulatory response:• Augmenting water supplies (e.g. recharge, reservoir re-operation)• Changing crops and cropping practices (e.g. specialty/high value crops, fallowing, dry land farming)
• Will assess economic effects on agricultural production using SWAP model.