There is increasing pressure for the full environmental consequences o
f investment decisions to be included in project appraisal procedures.
Environmental economic valuation techniques offer the potential for m
onetary values to be systematically estimated for such consequences an
d thus allow their inclusion in project analysis. A review of these te
chniques has been undertaken, and by way of testing their practical ap
plication a desk-top valuation of Rutland Water, UK, has been carried
out. The results indicate that the total annual value of the reservoir
is between pound 123 million and pound 215 million. However, of this
total a minimum of 64% is attributable to functions additional to its
primary purpose as a source of potable supply. The magnitude of these
additional values indicates that confidence in them can only be achiev
ed by further investigation into their theoretical and methodological
basis.