Valuation of Wetland Services

Hi all Wetlanders

My colleague is currently reviewing various environmental valuation methods as part of his M.Sc research project. One of the valuation methods is referred to a Replacement or Substitute Cost Method. The replacement cost refers to the replacement of ecosystem functions with artificial structures and systems that will replicate the ecosystem function, such as water purification and retention, to determine its economic value. However, not all ecosystems can realistically be replaced or replicated by artificial structures and systems, making its use rather limited. An approach with the replacement cost method for wetlands would be to obtain engineering costs for the construction of water purification plants per mega-litre treating capacity and to use the total water treatment output of the wetland over a certain time period to obtain a value for the ecological function. I would appreciate it if you could refer this to some experts in this field who have either developed or knows of such costing models. There are a variety of variables that could be considered in such a model such as size of wetland in terms of volume of water treating/ storing capacity; treating efficiency (input TDS vs. output TDS).

This research project investigates a number of valuation methods,
legislation, locality specific variables and ease of application considering
various moderators. I can therefore not digress into too much detail and
such model will have to be demystified/ simplified with capacity for
assumptions and desktop work. This is unfortunately some compromises
environmental resources economics has to allow for, as our resources, time, and knowledge about the environment is limited.

Your inputs, recommendations, references and general comments/advise would be appreciated.

Regards

Stephan Du Toit (M.Sc Pr.Sci.Nat.), Specialist: Environmental Protection,
Mogale City Local Municipality, PO Box 94, KRUGERSDORP, 1740
083-306-3441; stephant@mogalecity.gov.za