WaterWare models:   STREAM water quality Model

STREAM describes water quality in the open channels of the network in terms of:

1. DO/BOD
2. conservative tracers
3. arbitrary pollutants characterised by a first order decay.

Model Input

A STREAM scenario consists of:
• a WRM scenario/results it is based on;
• a few parameter that apply globally to the entire scenario;
• node specific parameters;
Note that any changes to the underlying WRM scenario might affect the STREAM scenario also, since STREAM uses the network structure and flow data from WRM.
In addition to the WRM scenario, STREAM specifies pollutant inputs in terms of concentrations for:
• START NODES (here also the specification of DO concentration of any input is required).
• DEMAND NODES (where the concentrations are applied to the dynamically computed return flows.

Model Processes

Model results:

The results include:
• basic statistics for BOD/DO, and the tracer including average. minimum, maximum values, average above (or below) threshold, calculated over all reaches and the internal, computational resolution;
• overall mass budget of pollutants;
• a summary of compliance/exceedances of water quality standards; please note that compliance and violations are only evaluatedf at control nodes the % values are based on the total number of simulated monitoring instances (control nodes * number of days);
• a color coded (average DO concentration by reach) displayed of the network;
• node specific dynamic results (time series) which are recorded and displayed for user selected control nodes.

• Economic Evaluation: STREAM performs an economic assessment of a scenario simlar to WRM. It estimates both direct and indirect costs, as well as direct and indirect benefits, and provides an economic summary for any model run.

  The economic assessment includes:

  • costs of wastewater treatment
  • costs of emission reducing technologies at demand nodes
  • costs (penalties) of exceeding quality standards at control nodes
  • benefits of satisfying demand with water that meets the quality objectives
  • benefits of meeting quality targets at control nodes;
  • benefits of quality dependent in-stream use (recreational) on a reach basis.