What CE-QUAL-W2 can model

Two tightly coupled engines — hydrodynamics and water-quality kinetics — solved on the same laterally averaged grid, from a single reservoir to a branched river-basin network.

🌊

Hydrodynamics

Solves the laterally averaged equations of fluid motion to predict water-surface elevations, longitudinal and vertical velocities, density and temperature — the physics that drives stratification and transport.

🧬

Water quality

Rides on the hydrodynamic transport to simulate dozens of interacting constituents — oxygen, nutrients, multiple algal and zooplankton groups, organic matter, carbonate chemistry and sediment exchange.

Hydrodynamic engine

Resolve stratification, mixing and transport

Because it resolves the vertical, CE-QUAL-W2 captures the processes that simpler 1D models cannot — thermoclines, selective withdrawal and density currents.

    TYPICAL VERTICAL TEMPERATURE PROFILE
    surface bed temperature → epilimnion (warm) thermocline hypolimnion (cold)
    Water-quality constituents

    A complete biogeochemical toolbox

    Group the state variables by the cycle they belong to. Modern releases let you define an arbitrary number of algae, epiphyton, zooplankton, CBOD and generic user constituents.

    💡

    Derived variables, automatically. Beyond the state variables, the model reports derived quantities such as total nitrogen, total phosphorus, total organic carbon, chlorophyll-a, dissolved-oxygen saturation and pH — ready for comparison against standards and observations.

    Structures & boundary conditions

    Operate the system, not just the water

    Represent the engineered controls that shape real reservoirs and rivers.

    😎

    Outlets & withdrawals

    Selective withdrawal, multiple ports, structures and floating intakes.

    💧

    Spillways & gates

    Spillways, gates, weirs, pipes and pumps with rating curves.

    Ice & heat exchange

    Surface heat budget, evaporation and an ice-cover formation/melt model.

    🌊

    Time-varying BCs

    Inflows, outflows, meteorology and constituent loads as time series.

    Applications

    Proven across waterbody types & questions

    A few of the many study types CE-QUAL-W2 supports.

    Map these capabilities onto your system

    Download the model and the example data sets to see the workflow end-to-end.