Funded by government, and implemented in 2003, the Water Balance Model Online is a scenario comparison and decision support tool. It operationalizes the Water Balance Methodology that is the technical foundation for Stormwater Planning: A Guidebook for British Columbia, released in 2002. The tool fills a gap not covered by commercial software.
Use less water. Mimic natural flows in streams. Preserve the natural pathways by which water reaches streams. Slow, spread and absorb runoff.
The Guidebook established a guiding principle that achievable and affordable performance targets at the watershed scale provide a starting point to guide the land use actions of local government in the right direction. The Water Balance Model Online enables the user to evaluate and establish performance targets for rainwater capture and runoff control. The desired outcome is to protect and/or restore stream health.
Test Drive the Online Demo!
Register for a Trial Account. Application is limited to a maximum 0.5 hectare site area. For a 30-day period, trial users are able to:
- try out the basic features of the tool;
- access the climate station database;
- set up simple scenarios;
- test how to reduce surface runoff from a site;
- assess green infrastructure effectiveness; and
- do multi-year scenario comparisons.
Full access to the complete suite of tool capabilities, including specialized modules as listed below, is restricted to participating local governments and paying subscribers. To learn more about this option, contact firstname.lastname@example.org.
Online versus Desktop Versions?
The Water Balance Model Online is the original web-based decision tool developed in 2003 by an inter-governmental partnership. Users can adjust only 3 of the 40 commands in the QUALHYMO engine. The rest of the commands are pre-set with default values.
The user interface is friendly. The Water Balance Model Online makes it easy for land use and watershed planners to test and learn from their assumptions when developing soil-based ‘green’ solutions that slow, spread and absorb (sink) rainwater runoff.
The Water Balance Model Desktop is a downloadable advanced user interface for the QUALHYMO engine. Experienced users can adjust one-third (1/3) of the 40 commands in QUALHYMO!
The Desktop gives the user more responsibility to drive the QUALHYMO engine. This means the user must have advanced expertise in hydrology, complemented by a good understanding and working knowledge of watershed management principles and practices.
|Category||Feature Set||WBM Online||WBM Desktop|
|APPLICATIONS||Watershed level planning - comparing BMP and rainwater management strategies|
|Residential lot planning - evaluating what kinds of BMPs to use, and how to place them.|
|Ad hoc analysis of runoff quality/quantity with/without BMPs and receiving streams.|
|Establish watershed targets and detailed design of strategy implementation|
|COMPUTATIONAL SCOPE||Flexible configuration to many alternative situations devised by user.|
|Water quantity simulation capable|
|Water quality simulation capable|
|DATA SOURCES||Includes preconfigured rain, temperature, evapotranspiration|
|Allows user defined rain, temperature, evapotranspiration|
|Allows arbitrary series length and time step|
|Allows user to determine land surface and tree canopy parameters|
|User configurable to any Canadian, US, or world-wide hydrologic region|
|USER SKILL SET||Must have advanced expertise in hydrology and source-control performance|
Modules & Engine
The Water Balance Model Online allows modellers to complete computer simulations in minutes rather than taking days or even weeks.
Water Balance Modules include: Climate Change, Stream Erosion, Tree Canopy Rainfall Interception, Rainwater Harvesting.
The Water Balance Model Online is powered by the QUALHYMO calculation engine, which was developed by Dr. Charles Rowney for Ontario’s Ministry of Environment in the 1980s. A strength of QUALHYMO lies in the erosion and flow-duration routines. These are key to application of the Water Balance Methodology.
DID YOU KNOW:
In 2004, the Canada Mortgage & Housing Corporation funded creation of a national portal, with the goal of encouraging use of the Water Balance Model Online across Canada. Because Environment Canada was co-chair of the inter-governmental partnership, this enabled access to the Atmospheric Environment Service climate station database. As a result, the Water Balance Model Online is populated with climate stations representing each province.
At the time of registration, the user selects the desired province. This automatically defaults the model to the stations within that province. Additional climate stations will be uploaded upon request.
Understand the Watershed as a Whole System
“Unless and until land development practices mimic the natural water balance, communities cannot expect to restore the biological communities within streams. Simply put, hydrology hits first and hardest.”
Dr. Richard Horner, Professor Emeritus
University of Washington, Seattle
“To be useful…the simulation model must be physically based and deterministic, and it must be designed to simulate the entire hydrological cycle…hence it must be a water balance model.”
Dr. Ray Linsley (1917-1990), Professor
(author, innovator & pioneer modeller)
Stanford University, California
Water Balance Pathways
Watershed protection starts with an understanding of how water gets to a stream, and how long it takes (refer to illustration below). The flow of rainwater from cloud to stream is comprised of three water balance pathways:
- surface runoff;
- interflow; and
- deep groundwater (aquifer flow).
In coastal British Columbia, for example, interflow is the primary pathway in an undeveloped watershed. Therefore, it is deemed to be vitally important. In everyday language, interflow is defined as the shallow horizontal movement of water through the surface soil ‘sponge’.
Historically, the community development and infrastructure servicing process has overlooked, ignored or eliminated interflow.
Whole-System, Water Balance Approach
- Understand where the water goes naturally and reproduce those conditions.
- Restore sub-surface interflow to maintain hydrologic integrity.
- Maintain the proportion of rainwater entering a stream via each of 3 water balance pathways!
- Replicate the streamflow-duration pattern to mimic the Water Balance.
Try the Water Balance Model Online
Register a (free) “trial” account. As a trial account registrant you are free to access the basic features of the model