The ecohydrological model SWAP has a history of more than 40 years. The first version was called SWATR and was developed by Reinder Feddes and co-workers in the Netherlands and was published in 1978. During its history updates were distributed regularly with derived acronyms: SWATRE, SWACROP, SWAP93, and SWAP.

Over the years the funding came from several sources; in the beginning mostly by the Dutch Ministries. More recently, the maintenance and further development of SWAP is financed by subsidies that came from different sources.

We would like to acknowledge the following project/organizations for funding SWAP.

Watervision Agriculture ("Waterwijzer Landbouw")
see also WUR WaterwijzerLandbouw
Dutch Ministry of Agriculture, Nature and Food Quality (and predecessors)
EU SIGMA project