Gardner and Young
Salinity Control Evaluation
marize a subsequent regional task force’s
studies of agricultural, municipal, and in-
direct salinity damages. Related investi-
gations have been reported by Oyarzabal
and Young concerning impacts in Mexico
and Boster and Martin regarding central
Arizona. The U.S. Bureau of Reclamation
(1980) summarized the government’s
analysis of expected economic impacts.
The Colorado Water Quality Improve-
ment Program has overseen studies of the
costs of specific salinity control projects
(USBR, 1983). Although the total program
cost could exceed one-half billion dollars,
little professional discussion of the pro-
gram has ensued. The USBR, for its part,
has chosen a “cost-effectiveness ap-
proach.” The cost (in dollars per milli-
grams per liter) of annual salt load reduc-
tion in the River is estimated, and priority
given to those projects exhibiting lowest
cost per unit of salt reduction. General-
ized Lower Basin benefits of salinity
abatement have also been developed
(USBR, 1983:21). Curiously, however, no
direct project-by-project comparison of
benefits and costs has been publicly re-
ported. Costs are identified in differing
places and format from reported benefits,
and only a persistent specialist is likely to
succeed in piecing together the total pic-
ture. There are indications that federal of-
ficialdom, while willing to prioritize proj-
ects according to cost-effectiveness, would
prefer not to evaluate the program on a
full economic efficiency criterion. We be-
lieve, in contrast, that the economic effi-
ciency criterion should play a major role
in evaluating this program, and that only
those projects should be funded for which
the economic gains to downstream water
users clearly outweigh costs.
From our review of the procedures em-
ployed in developing the economic ben-
efit estimations reported by the Bureau of
Reclamation, it appears that the treat-
ment of benefits overlooks several impor-
tant conceptual issues. We believe that the
official estimates significantly overstate the
downstream damages caused by the Col-
orado River and therefore overstated the
economic benefits of salinity abatement.
The objective of this article is to report
the assumptions and procedures of our re-
evaluation of the issue, and to provide a
project-by-project examination of the eco-
nomic feasibility of the salinity control
program.
Procedure
Benefits of salinity control are defined
in terms of “economic damages avoided.”
Our general approach is to re-estimate ag-
ricultural damages-avoided and update the
municipal damages-avoided estimates
from the earlier basin-wide impact study
(USBR, 1980). These revised damages-
avoided estimates are then adjusted to ac-
count for the several years required for
salt pickup reductions from the Upper Ba-
sin control projects to be recorded as low-
er salinity at Imperial Dam. Expected an-
nual benefits are compared with estimated
equivalent uniform annual costs for each
of nineteen projects to assess economic
feasibility. Economic feasibility is defined
as real annual equivalent benefits in excess
of real annual equivalent costs (James and
Lee, pp. 509-12).
Costs and Cost-Effectiveness
Due to lack of both expertise and re-
sources, we utilize without adjustment the
federal estimates of project costs and of
the physical reductions in salt loading
(USBR, 1980). However, previous experi-
ence suggests that the estimates of both
project costs and effectiveness in reducing
salt are highly problematical. There is
limited direct knowledge of the physical
and hydrologic relationships underlying
the salt-loading process, and experimen-
tation to refine knowledge is expensive and
time-consuming when it is possible at all.