Calculating Physical Changes Using Models - California · PDF fileWater Storage Investment Program Overview of Model Use •Tools used to inform decisions • Project applicants: quantify

Water Storage Investment Program

Calculating Physical Changes Using Models

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Overview

•Modeling Overview

• Model Use • Analysis Framework • Water Resources Operations Models • Model Selection

•Published Climate Change Datasets

•Groundwater Analysis • Methods and applications • Model selection • Publicly available resources

•Emergency Response

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Benefits Quantification/Cost Allocation Framework

Economics Models may be needed –not covered in this Webinar

Models needed

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Overview of Model Use

•Tools used to inform decisions • Project applicants: quantify the benefits (physical and monetary) • Model results form the basis for Commission’s decisions

•Common to all models (simple to complex): • Assumptions • Data quality • Spatial and temporal scope and resolution • Limitations

•Extent and level of detail of modeling must be appropriate to the project, and the decision to be made

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Analysis Framework

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Analysis Framework: Example

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Priority: Provide cold water at times and locations to increase the survival of salmonid eggs and fry

•Surface Water Operations: River flows, reservoir releases, reservoir storage, Delta operations, etc.

• Delta Conditions: Safe Delta passage for adults, juveniles • Surface Water Quality model: Riverine water

temperature, river flow • Aquatic Resources: Survival, wetted usable area, food

supply, etc.

•Physical Change: Increased flow, colder riverine water temperature, increased wetted usable area for nesting, increased food supply, etc.

•Physical Benefits: Increased survival rates of salmonid eggs and fry, or escapement

•Monetized Benefits: $$


Analysis Framework: Example, Continued

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Analysis Framework –System operations

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Water Resources Operations Models Components:

•Water balance: Accounting of all the flows of water into and out from an account for a defined period of time

•Hydrologic Information: River inflows, runoff due to precipitation, evaporation, evapotranspiration, consumptive use, and return flows of water demands, etc.

•Physical features and constraints: stream channels, reservoirs, penstocks, diversion structures, canals, pumps, drains, gates, weirs, etc.

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Water Resources Operations Models-Continued

Components:

•Requirements: Permits, licenses, (SWB) decisions, water rights, biological opinions, water control manuals, etc.

•Agreements: Contracts, settlement agreements, a coordinated operation agreement with another water project, etc.

•Operations criteria: Formal or informal decisions based on legal requirements or past experience of the water project operators

•Decision Framework: Hierarchy of decisions to be made to comply with requirements, agreements, and operations criteria (such as allocation decisions)

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Water Resources Operations Models-Continued

Modeling with vs without project conditions at any point in time:

•Physical features and constraints specific to the project • Modeling of project storage and related facilities • Conveyance of water (model connectivity)

•Agreements specific to the project • Agreements between cost share partners

•Operations criteria specific to the project • Criteria on how best to operate the project

•Decision Framework specific to the project • Decision framework based on prioritization of benefits

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Water Resources Operations Models Continued

Modeling 2030 vs 2070 conditions (with project):

•Hydrologic Information • Climate change effects (precipitation, temperature,

runoff, sea level rise, etc.) • Section 2.12

• Appendix A

• Land use • Water demands

•Operations criteria specific to the project • Criteria on how best to operate the project

•Decision Framework specific to the project • Decision framework based on prioritization of benefits

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Model Selection – minimum requirements Section 4.2.1:

•Scientifically defensible: best available science, model limitations and uncertainty understood • Models need to be justified and documented (except for the published models by CWC)

•Encompass the geographic scope necessary to quantify all benefits or impacts

•Appropriate time step sufficient to quantify benefits or impacts

•Capable of interacting with the other models in the analytical framework • Spatial and temporal resolution • Consistent data and assumptions between models

•Sufficient data should be available to meet the model’s requirements

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Model Selection - complexity •Detailed as needed to reflect project benefits or impacts

• Spatial resolution • Temporal resolution • Data collection, calibration • Model Methodology (1D, 2D, 3D, analytical, numerical, etc.) • Type of benefit/impact process (physical, biological, etc.)

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Model Selection: Example 1

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Small, local project, little to no effect on overall system, benefits/impacts analysis does not require complex modeling

Models Hydrology

• Project-specific operations model ( justified and documented by the applicant) describing with and without project conditions

• Additional resource models as needed to quantify benefits/impacts of the project

• Regulatory requirements and agreements shall not be modified

• “No system-wide effect” needs to be justified

• Statewide gridded data • CalSim II datasets published for

2030 and 2070 conditions



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Large projects with significant effect on overall system and benefits/impacts require complex analysis

Models Hydrology

• Published CalSim II and DSM2 models provided for 2030 and 2070 • Additional resource models as needed to quantify benefits/impacts

of the project • Adjustments to published CalSim II and DSM2 models to provide

detail for project benefits/impacts must be justified and must be included in with and without project condition

• Regulatory requirements, agreements, and operations criteria of the SWP and CVP in the CalSim II model code for the 2030 without-project and 2070 without-project future conditions shall not be modified. Modifications of operations criteria specific to evaluation of the project and its integration with SWP and CVP and other projects must be justified.

• CalSim II datasets published for 2030 and 2070 conditions

• Statewide gridded data, if needed



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Regional/ watershed project , potential effect on overall system, benefits/impacts require minimal to large complexity

Models Hydrology

• Project-specific operations model ( justified and documented by the applicant) describing with and without project conditions

• Can the project have system-wide effect including effect in Delta? • Yes: Published CalSim II and DSM2 models provided for 2030 and 2070 (linked to project-

specific operations model for with and without project conditions) • No: Justify

• Additional resource models as needed to quantify benefits/impacts of the project • Regulatory requirements, agreements, and operations criteria of the SWP and CVP in the CalSim II

model code for the 2030 without-project and 2070 without-project future conditions shall not be modified. Operations criteria specific to the project or specific to the integration of the project with SWP and CVP may be modified.

• Statewide gridded data

• CalSim II datasets published for 2030 and 2070 conditions


Climate Change and Sea Level Rise

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Climate Change Methodology Overview

•Selection of GCM projections (10 GCMs under 2 RCPs)

•Statistical downscaling of GCM data

•Detrending of daily Historic Temperature Data

•Quantile Mapping of Projected Climate

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• VIC Model Application for the WSIP

• VIC Model Watershed Delineation and Routing Network

• VIC Model Calibration

• Bias Correction of VIC Model Results

• Incorporate projected runoff obtained from VIC

• Perturbation of streamflows for smaller watersheds

• Re-impairment process

• Updating water year types and indices

• Incorporating sea-level rise on flow-salinity response

CalSim II model simulation of storage, flows, and diversions for the major tributaries of the Central Valley under climate change (2030, 2070) with sea level rise (2030 15 cm, 2070 45 cm) for water years 1922 through 2003

DSM2 model simulation of flow and salinity conditions for Delta channels with sea level rise for water years 1922 through 2003


Published Climate Change Datasets •CalSim II and DSM2 models and VIC Statewide Gridded Dataset:

• 2030 Median Scenario • 2070 Median Scenario • 2070 Drier, Extreme Warming (DEW) (Optional for uncertainty analysis) • 2070 Wetter, Moderate Warming (WMW) (Optional for uncertainty analysis)

•Also provided for reference only: • Historical Temperature-detrended VIC Statewide Gridded Dataset

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Statewide gridded data of VIC input and output variables for each 1/16-degree spatial resolution grid cell over the period Jan-1915 to Dec-2011. Available inputs and outputs parameters are as follows:

• Precipitation (mm) - VIC Input

• Tmax (deg C) – VIC Input

• Tmin (deg C) – VIC Input

• Surface Runoff (mm) – VIC Output

• Baseflow (mm) – VIC Output

• Snow Water Equivalent (mm) – VIC Output

• Potential Evapotranspiration (mm) -short grass– VIC Output

• Potential Evapotranspiration (mm) -tall grass – VIC Output

• Soil Moisture (mm) – VIC Output

VIC Statewide Gridded Dataset

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CalSim II & DSM2 Datasets CalSim II Climate Inputs for 2030 and 2070:

•Reservoir Inflows

•Valley floor runoff

•Forecasted flows

•Water year types and other indices

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All CalSim II outputs:

•Reservoir storage, release

•Streamflow

•Deliveries

•Delta Outflow, etc.

All DSM2 outputs:

•Flow

•Salinity, etc.


Calculating Physical Changes: Groundwater Analysis

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When is a Groundwater Analysis Needed? 1. Storage projects affecting groundwater resources, or

2. Claim benefits related to groundwater physical change, or

3. Groundwater-specific storage project: ◦ Groundwater storage (or recharge) projects ◦ Groundwater contamination prevention or remediation projects that

provide water storage benefits ◦ Conjunctive use projects

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Physical Change Analysis

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Analyze both benefits and impacts


SGMA Considerations Groundwater and water system analysis must incorporate elements of consistency with SGMA requirements such as:

• Identifying which of the six undesirable results defined in SGMA and listed in the proposed WSIP regulation may be improved or worsened by the proposed project.

• Describing how the management and operation of the proposed storage project might be integrated with the study area’s overall groundwater management.

• Coordinating with GSAs overlying the groundwater basins in which the proposed project is to be constructed to ensure local buy in and consistency with local management decisions and groundwater sustainability goals.

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Example Benefits Related to Groundwater Physical Change

Non-public

benefit

Public Benefit Category

Groundwater Physical Change

Water Supply

Ecosystems Water Quality

Flood Control

Emergency Supply

Recreation

Levels (also as it relates to subsidence)

√ √

√

√ √

Storage (also as it relates to recharge)

√ √ √ √

Quality √ √ √ √ √

Flow gradient/direction

√ √

Interaction with surface water

√ √ √

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Overview of Method Complexity Qualitative approach ◦ Example: Assess relative groundwater physical changes based on

change in surface water use versus reduced groundwater use (can be used to show benefit/no impact, but cannot be used for quantification)

Simple analytical tools ◦ Example: Spreadsheet tools ◦ Generally for the analysis of simplified representations of the

groundwater system

Complex, detailed numerical modeling packages ◦ Three-dimensional groundwater flow models, transport models, and

integrated surface water and groundwater models

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Groundwater Analysis Tool Selection

Approach Applicability Example Use

• Qualitative • Surface storage project that would not significantly affect groundwater

• Relate expected positive or negative change based on inferred responses of physical system

• Analytical • Simplifying assumptions to physical system –evaluate one change at a time

Evaluate: • Streamflow depletion • Recharge from a ponded storage basin

• Numerical • Holistic view of changes occurring through interconnections of various effects (highly recommended for complex sites, transient methods and GW-SW interaction analysis)

Compute: • Change in storage • Water levels and subsidence • Interaction with surface water • Gradient changes • Groundwater quality

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Groundwater Analysis Method Selection

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Example use of a Numerical Model to Quantify Benefits of a Storage Project

Purpose: use numerical model to compute change in water budget, water levels, interaction with surface water, gradient change

Method:

Outcome: assess potential for public benefits from proposed project based on physical changes to groundwater parameters

Modify input datasets in

calibrated model to create “without

project” run

Add features in the model to represent

storage project (surface storage, or recharge pond, or

injection wells)

Run model and review outputs

compared to without project

conditions (contour maps,

hydrographs, water budgets)

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Review Outputs (spatial, temporal, numeric)

Recharge pond

Surface water

inflows

Injection or

pumping wells

Quantifying Physical Change – Numerical Model Approach

Historically Calibrated Numerical Model Future Conditions

(with Climate Change)

Numeric: water budgets

Implement Changes due to Storage Project

Run models

Spatial: water level contours

Temporal: hydrographs

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Example System-Wide Physical Change and Benefit Analysis

Conceptual Conjunctive Use Project (remember example from last webinar)

• A river that is tributary to the delta has low flow and high temperatures in dry years

• Construct groundwater pumping and recharge capacity near river

• In wet years, divert flow into recharge or in-lieu storage

• Use some of the stored groundwater instead of river diversions in dry periods

Analysis: evaluate SW impacts, calculate water budgets before and after project • Improve storage, water levels? • SW conditions more favorable to ecosystem

habitat?

Source: Hydrogeologic Conceptual Model Best Management Practice (DWR 2016)

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Available Tools and References Existing Central Valley Model Applications

• C2VSim – DWR • Website: http://baydeltaoffice.water.ca.gov/modeling/hydrology/C2VSim/index_C2VSIM.cfm

• IWFM code: http://baydeltaoffice.water.ca.gov/modeling/hydrology/IWFM/index.cfm

• CVHM – USGS • Website: https://ca.water.usgs.gov/projects/central-valley/central-valley-hydrologic-model.html

• USGS GW software: https://water.usgs.gov/software/lists/groundwater

• USGS Model archive: https://ca.water.usgs.gov/sustainable-groundwater-management/california-groundwater-modeling.html

• GW Model Archive (SGMA site): • https://gis.water.ca.gov/app/gicima/

More complete list available in the Technical Reference Document

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http://baydeltaoffice.water.ca.gov/modeling/hydrology/C2VSim/index_C2VSIM.cfm

http://baydeltaoffice.water.ca.gov/modeling/hydrology/IWFM/index.cfm

https://water.usgs.gov/software/lists/groundwater

https://gis.water.ca.gov/app/gicima/


Publicly Available Groundwater Models (SGMA BMPs)

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Switching gears…

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Emergency Response

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Emergency Response Statute:

“including, but not limited to, securing emergency water supplies and flows for dilution and salinity repulsion following a natural disaster or act of terrorism.”

Regulation and Technical Reference:

•Delta levee failures, accidents, or terrorism that impact Delta water supply operations • Provide supporting data on occurrence frequency OR Assume it occurs once, 30 years into the

project’s operations • Use average hydrologic conditions including average project water storage and average storage

recovery conditions

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Emergency Response •Earthquake events that impact local or regional water supply operations

• Provide supporting data on occurrence frequency OR Assume it occurs once, 50 years into the project’s operations

• Use average hydrologic conditions including average project water storage and average storage recovery conditions

•Drought emergencies - water supplied for human health and safety purposes during declared emergencies • Use the hydrologic dataset used in the project’s operations analysis • Can be assumed to occur during a critical year if it is the third or later year of any multi-year

drought period that occurs in that dataset

•Wildland fire emergencies • Use average summer conditions • Provide data to justify the frequency of occurrence used to calculate benefits

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Example Calculations for Emergency Response for Delta Event

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•Assumptions for this example: • Proposed project storage capacity = 120,000 AF • Applicant commits to release up to 33% of whatever is in storage at time of emergency event • Monthly time-step (or more frequent) needed

•Define hydrologic and reservoir conditions at time of emergency. For purposes of analysis, “average conditions” can be: • The year having Median End-of-Year Storage based on the with-project operations analysis • An average year selected based on criteria defined and justified by the applicant • Several years representing water year types selected based on criteria defined and justified by the

applicant (with final benefits calculated as the weighted average) • Other year or years selected based on criteria defined and justified by the applicant

• For the selected year, consider the months in which the emergency could occur


Example Calculations: Emergency Response

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Water Released if Emergency happens

EOM Storage if Emergency happens

(EOM - Release)

7,500 14,5007,167 13,8338,333 20,667

12,667 34,33322,000 63,00034,167 85,83340,000 80,00040,000 80,00038,333 71,66730,167 40,83317,167 14,833

9,167 13,833

Show Emergency Supplyfor each possible month

Inflow

Water Released/ Delivered for all

Uses Spill EOM StorageSept 23,000Oct 1,000 2,000 0 22,000Nov 1,000 2,000 0 21,000Dec 10,000 2,000 0 29,000Jan 20,000 2,000 0 47,000Feb 40,000 2,000 0 85,000Mar 40,000 4,000 1,000 120,000Apr 30,000 6,000 24,000 120,000May 20,000 10,000 10,000 120,000June 10,000 20,000 0 110,000July 1,000 40,000 0 71,000Aug 1,000 40,000 0 32,000Sept 1,000 10,000 0 23,000

If no Emergency Supply(Results from operations model)


Example Calculations (continued)

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Calculations for each event for each monthMay event: Release extra 40,000 AF for emergency/

Delivery plus emergency

release Spill EOM Storage Change in delivery

Change in spill

Sep 23,000Oct 2,000 22,000Nov 2,000 21,000Dec 2,000 29,000Jan 2,000 47,000Feb 2,000 85,000Mar 4,000 120,000Apr 6,000 120,000May 50,000 80,000Jun 20,000 0 70,000 0 0Jul 40,000 0 31,000 0 0Aug 31,000 0 1,000 9,000 0Sep 1,000 0 1,000 9,000 0Oct 1,000 0 900 1,200 0Nov 900 0 1,100 900 0Dec 1,100 0 8,000 400 0Jan 2,000 0 22,000 0 0Feb 2,000 0 50,000 0 0

Calculations for each event for each monthJune event: release extra 38,333 AF for emergency/

Delivery plus emergency

release Spill EOM Storage Change in delivery Change in spill

Sep 23,000Oct 2,000 22,000Nov 2,000 21,000Dec 2,000 29,000Jan 2,000 47,000Feb 2,000 85,000Mar 4,000 120,000Apr 6,000 120,000May 10,000 120,000Jun 58,333 71,667Jul 40,000 0 32,667 0 0Aug 32,667 0 1,000 7,333 0Sep 1,000 0 1,000 9,000 0Oct 1,000 0 900 1,200 0Nov 900 0 1,100 900 0Dec 1,100 0 8,000 400 0Jan 2,000 0 22,000 0 0Feb 2,000 0 50,000 0 0


Example Calculations (continued)

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•Repeat for other months and for each year used to represent or construct average condition

•Calculate weighted average changes if more than one year or year type is used

•The physical changes to move forward into other analysis and monetization will include, as appropriate: • Quantity of emergency water released • Subsequent reductions in deliveries, instream flows, head and releases for hydropower, etc.

•For monetization and Present Value calculations, place the Delta emergency event and subsequent other changes at the 30-year mark in project operations


Questions?

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Documents

Calculating Physical Changes Using Models - California · PDF fileWater Storage Investment Program Overview of Model Use •Tools used to inform decisions • Project applicants: quantify