What is OASIS with OCL™


OASIS is a unique software program that realistically simulates the routing of water through a water resources system. OCL™ (Operations Control Language) is a computer language that allows the water system operator to express any condition or rule, and enter it into the software. OCL also acts as a bridge from OASIS to other computer programs. Users can express all operating rules as operating goals or operating constraints, and can account for both human control and physical constraints on the system. To model any system, one simply needs to approach the problem as a set of goals and constraints. The software then solves for the best means of moving water through the system to meet these goals and constraints. OASIS with OCL, in effect, serves as a "smart router."

OASIS evolved from HydroLogics' work in modeling water resources systems throughout the United States and internationally. Out of that experience, we developed OASIS with OCL to implement the following features:


  • Maximum Flexibility
    OASIS is completely data-driven. With the use of OCL, any operation can be described, including conditional ("if-then") operations, and can be modeled without modifying OASIS' source code.
  • Simulation of Operators' Behavior
    Because OASIS software simulates routing decisions, all simulation rules are represented as either goals or constraints. The fact that rules can be modeled as goals is particularly important, because goal-seeking behavior is an efficient modeling approach that corresponds very well to the way real-world operators and planners think about a water system.
  • Ease of Use
    OASIS features a graphical user interface (GUI), which shows water systems in the form of user-definable maps and diagrams, and which allows users to operate the software in a familiar environment of pull-down menus and dialog boxes.
  • Compatibility
    OASIS can run "parallel" with other models. OCL allows data to be sent and received between OASIS and other programs, while the programs are running. Each program can then react to the information provided by the other.
  • Database Utilization
    OASIS input and output is stored in standard databases: static data is kept in Microsoft Access or other relational databases, and time-series data is kept in HEC-DSS databases.
  • Standardized Task Handling
    OASIS is designed specifically to model the operations of water resources systems, and thus relies on many standardized features that are appropriate to that kind of modeling. For example, OASIS knows how to compute evaporation from a reservoir, and to handle flow capacities and minimum flow targets. It also automatically ensures that the continuity of flow is maintained.


OASIS with OCL, along with its graphical user interface and post-processing programs, is an extremely powerful tool for water managers. It enables them to see how their system reacts to demand management options, supply management options, changes in operational rules, or changes in facilities, and helps provide managers with a realistic measure of their system's reliability.

For an in-depth look at OASIS, download the OASIS product sheet PDF here.


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