PCWA MFP Operations Model

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PCWA MFP Operations Model

• All Models are Wrong
• But
• Some Models are Useful

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What is a Model?

• A Simulation Model is a mathematical
  representation of a physical system that
  includes
• Rivers
• Reservoirs
• Conveyance and Release Facilities
• Tunnels, Penstocks Powerhouses,
• Streamflow release valves
• Operating Rules, Licenses and Agreements

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What is a Model?

• The Model routes water (Input Hydrology) through
  the System (mathematical representation of the
  physical world) according to Rules

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What is a Model?

• A model chooses how water is routed through the
  system in order to meet certain criteria and
  goals.
• A model allows us to measure the impact that
  changes to the input set will have on the output
  set.

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What are the Rules?

• Rules are inputs to the Model
• Rules represent decisions made by the operators
• Rules fix operating parameters that can vary from
  run to run

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Examples of Rules

• Instream flow requirements
• Storage level requirements and targets
• Use of discretionary water supplies
• Meet Consumptive Demands
• Generate Power
• Provide Recreation

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Other Model Inputs

• Flow (Hydrology) - PCWA believes that it has a
  reasonably accurate record of Project flows since
  the project began operation in 1968
• For each different set of inputs, we intend to
  generate output using the same identical set of
  historic hydrology

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Other Model Inputs

• Fixed Criteria - project parameters that cannot
  be changed without physical alteration of the
  Project. Fixed Criteria include
• Tunnels and Turbine capacities
• Outlet capacities
• Elevations

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Other Model Inputs

• Water Supply Demands - special class of Rules
• Consumptive demands at Folsom Reservoir
• Consumptive demands at Auburn Pump Station
• Environmental Demands (Water Forum Agreement)

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Model Outputs

• Tables to verify that the Rules are met
• Rules guide the operation of the model, but may
  not be met 100 of the time. For example, minimum
  instream releases will not be met if a reservoir
  runs dry. Having the flexibility to violate rules
  helps provide information.

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Model Outputs

• Reservoir Level Trace
• Identify excursions from preferred operation -
  too high (spills and loss of generation) or too
  low (risk of failure to meet consumptive demand)
• Power Generation

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Benchmark and Baseline

• A Benchmark Run is used to verify that the model
  reasonably represents actual historic operations
• The Baseline Run is the run against which all
  Alternative Model Runs are compared to determine
  the impacts of proposed conditions on the MFP
  operation

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Benchmark and Baseline

• PCWA proposes that the difference between the
  Benchmark and the Baseline Runs is that the
  Benchmark Run uses historic consumptive water
  demands and the Baseline Run uses buildout
  consumptive water demands

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Using the Model
Alternative Study
Baseline Study
Hydrology
Hydrology
Consumptive Demands
Consumptive Demands
Input
Input
Fixed Criteria
Fixed Criteria
Operating Rules
Operating Rules (Changes)
Model
Model
Verification Tables
Verification Tables
Output
Output
Reservoir Levels
Reservoir Levels
Generation
Generation
Inside Model
Assess Impacts
Assess Impacts
Outside Model
Compare
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Assessing Impacts

• The Model Does Not assess environmental impacts
• The model only provides comparative information
  on water supply and power generation for Alt
  Model Runs
• Assessment of the full impacts of any Model Run
  is done by people

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Assessing Impacts

• An analysis of the benefits and costs of each
  alternative may be viewed differently by each
  person
• To develop alternatives based upon environmental
  parameters requires completion of the 1st year of
  field studies. March 2009.

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Alternative Model Runs

• The desire to create a given environmental
  condition leads stakeholders to suggest changes
  to the rules
• The resulting model run shows the impact of the
  rule change on water supply and power generation

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Where are we now?

• The Model is operational
• Benchmark input set has been assembled for
  testing
• A draft users manual has been prepared

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What do we do until 2009?

• Verification
• Education
• Development (betterments, hourly)
• Investigate physical limitations
• Find our sideboards Dry year issues, Ralston
  Afterbay flexibility

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How do we get there?

• Process We need good process around our group
  understanding of how Modeling Alternatives are
  developed, run and assessed