New Version of WEAP

September 2007

The Stockholm Environment Institute is proud to announce the release of a major new version of WEAP, the Water Evaluation And Planning system.  WEAP is an advanced Windows-based tool that has been widely adopted by water resource planners around the world. 

WEAP is notable for its integrated and policy-oriented approach to water planning, which emphasizes a holistic view of both demand and supply management techniques.

WEAP’s user-friendly, GIS-based interface makes complex water management problems much easier to address than conventional water planning models, and its focus on the use of transparent modeling methods makes it ideal for use as a capacity building and teaching tool.

The new version builds on these strengths. Highlights include:

• Detailed Groundwater Modeling: In addition to its existing groundwater modeling capabilities, the new version now includes dynamic links to the USGS MODFLOW groundwater model. 
• WEAP’s surface water quality modeling can now be extended through a dynamic link to the US EPA QUAL2K model.
• New Rice Paddy Module: Track the requirements for and hydrological effects of rice cultivation (and wetlands).
• Powerful New Modeling Architecture. WEAP’s modeling capabilities have been given a major upgrade.  For example, WEAP now includes an Application Programming Interface (API) which enables WEAP to interact with and be controlled by other modeling tools including any standard Windows-based programming or scripting language.    WEAP’s own calculations can also be extended through the ability to call other models from within WEAP.
• Multilingual Tool: The new version of WEAP now operates in a choice of languages: English, Chinese, French, and Korean with partial translations into Arabic, Farsi, Portuguese, Russian, Spanish and Thai.
• Scenario Comparisons: WEAP’s powerful reporting features have been upgraded to enable scenarios to be directly compared on screen in a single chart or table.
• Faster: WEAP’s calculations are now much faster.
• Improved Documentation and Training Materials: The WEAP Tutorial has been revised to cover many of the new features.  It is available here: http://www.weap21.org/Tutorial

For a description of these and the other changes, see http://www.weap21.org/WhatsNew

Recent WEAP Applications

WEAP is currently in use at over 100 sites around the world.  Recent activities with WEAP include:

• Advancing stakeholder involvement and cooperative decision-making structures in watershed planning processes
• Assessing vulnerability to climate change and devising adaptation strategies
• Financial planning by water utilities
• Analyzing groundwater impacts of water management and use (using WEAP-MODFLOW linkage)
• Examining trade-offs and interactions between water allocated for food security and for environmental processes
• Understanding links between water and rural livelihoods
• Modeling downstream impacts on water quantity and quality from upstream agricultural activities and wastewater return flows
• Considering evapotranspirative demands in maximizing both ecosystem health and water supply
• Investigating re-operation of reservoirs to maximize flows to meet both human and ecologic needs

The new version is available from the WEAP web site: http://www.weap21.org/Download 

Existing users can get the new version using the Help: Check on Internet menu option built into WEAP.  The new version is backwards-compatible with older versions--it will read and upgrade your current data sets. However, it is always advisable to make backups of your data before updating.

Licensed users of WEAP can upgrade to the new version free of charge.  WEAP is also free to academic, governmental and non-profit organizations based in developing countries.  See http://www.weap21.org/Licensing for more information and for licensing terms for other organizations.