CALSIM II

Criterion

Explanation

General Description

Calsim II is a model for water resources management that optimizes operation and allocation decisions in California's Central Valley. It is an application of an underlying model called WRIMS (Water Resource Integrated Modeling System) that has its own domain-specific language (WRESL) for describing operational criteria and translating them into a linear programming problem.

Model Domain

Calsim II is specifically an implementation of the areas served by the California State Water Project (SWP) and Central Valley Project (CVP) operations. It is used for official publications by the state of California, including its SWP delivery capability reports as well as by the wider modeling community.

Developer

CA DWR

Hardware computing requirements

XA Solver Hardware Key (Calsim II) if using XA solver

Code language

FORTRAN (underlying numeric code) / WRESL (model implementation)

Original application

Water operations and allocations for California Central Valley

Public/proprietary and cost

Calsim II model: GNU GPLv3

XA Solver (required for reference implementation of Calsim II, other options exist particularly for Calsim3): Proprietary, $1650

Physically or empirically based

Empirically based

Mathematical methods used

Surface water is represented as a network of nodes and channels. Model objectives and constraints are optimized via Linear Programming; certain processes (e.g. Delta salinity objectives) are approximated and linearized in calls to artificial neural network DLLs

Input data requirements

Reservoir inflows, valley precipitation, and operation objectives encoded as WRESL statements. Various studies are publicly available as starting points. A completely novel scenario involves extensive upper watershed modeling and careful representation of operational criteria in the WRESL framework.

Outputs

Outputs stored in DSS file (file format developed by Army Corp of Engineer's HEC) and include reservoir outflows and allocation decisions on a monthly timestep.

Pre-processing and post-processing tools

There is a WRIMS GUI built in the Eclipse framework that can help process and edit the model's (WRESL) files.

Representation of uncertainty

No explicit representation in the model output; could be implemented with multiple scenarios

Prevalence

The model is the de-facto standard for planning California Central Valley operations and SWP Delivery Capability Report studies

Ease of use for public entities

Barriers to widespread use include limited documentation and specific software environment for reference implementation.

Ease of obtaining information and availability of technical support

There is a Calsim user group, and DWR support contacts can answer some classes of self-contained questions. 

Source code availability

The model is licensed under GPL, but model source would need to be requested. Source code of certain model DLLs (salinity ANNs) does not appear to be publicly available.

Status of model development

Model is mature. Most future development is focused on a replacement framework, Calsim3

Model documentation is limited and a lot of developer and community attention is focused on releasing a newer version of the model, Calsim 3.