WSP00818

• File Number: 8273.100.50
• Description: Colorado River Basin Salinity Control - Federal Agency Reports - BOR
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 12/1/1980
• Title: Colorado River Salinity - Economic Impacts on Agricultural, Municipal, and Industrial Users
• Water Supply Pro - Doc Type: Report/Study

quality levels ,Ire maintained in boiler and
coolil1g systelTls by periodically adding an
amount of relAtively good-quality water
(makeup water) and discharging from the
system an equell volume of the poorer quality
water (hlowdowTl).

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E. Evaluation Procedures

The cost of applying alternative remedial actions
was determined lor each user, and the least
costly alternative or combination of alternatives
was selected Inr suhsequent analyses. Economic
studies were intnllded to provide a basis for
assessing the economic impact of a change in
salinity levels. Water quality, water use patterns,
?lnd economic conditions were projected for
each group of users. Through the application of
appropriate tin18-v;-1Iuc factors and adjustments,
mpresentative impact estim?ltes were made. The
individual prOCec1LJI es will vary for the different
users, but th8 results represent direct plus
indirect (in the case 01 agriculture) penalty costs
which are on <'1 comparable basis and can be
aggregated for tl", entire Impacted area.

'1. Agricllltlllc. l P (linear pronraming)
models were formulclted for each agricultural
Hrea curr-ently receiving. or- expected to
receive in the near future. water from the
Colorado River. Agricultural yield decrements
and fllternative management practices which
might be implemented by larmers as salinity
levels increase were evaluated by researchers
of the LJnivelsity of Arizona and the LJniversity
of California. Ih8se rohysical data were then
LJsed as inputs ror an LP profit maximization
model, wherein the optimal farmer response
to salinity chanqe is delineated. Optimization
results for solinity levels r-anging from 900 to
1400 mg/I wore used to estimate the
parameters o! ;1 dnm?lge function for each
irnpacted [1r8H.

BeCfluse of the interdependence of numerous
economic activities. there exist indirect
effects 011 the regional economy stemming
tmm the diruct economic impact of salinity
upon agriculturnl water users. These effects,
termed indirect pennlty costs. can be
determined if the interdependency of
economic activities is known. Procedures
were used to follow changes affecting any
agricultural illdustry through a chain of
transClctions in cnder to identify secondary or

indirect effects on the economy stemming
from the direct economic costs of salinity.
Though less confidence is placed in these
estimates, nevertheless. it should be
recognized that salinity affects more than just
the direct water users.

2. Municipal. A high level of TDS (total
dissolved solids) of water distributed by a
municipality will adversely affect individual
users. Such adverse effects relate to the
esthetic quality of the water and to the
operation and maintenance costs associated
with its beneficial use. Estimation of monetary
impacts (additional costs) for a typical
household was derived by calculating the
present worth of differing lengths of time for
typical household items associated with
different levels of.salinity. The objective of this
procedure was to determine the annual costs
of replacement required to maintain the
services of certa in household items over a
50-year period.' Examples of items affected
and repairs necessitated by the corrosiveness
of water include water heaters, piping and
fixtures, and water damage from broken
appliances.

The analytical procedure required that major
municipal users be identified. Since major
impacts and sizable population centers are not
found above Lake Mead. this study was
confined to the Lower Colorado River Basin
and divided into three separate areas. The
areas are (1) the MWD (Metropolitan Water
District) of California service area; (2) the CAP
(Central Arizona Project) service area, and
(3) the Lower Main Stem municipal service
area which includes cities along the Colorado,
in the Imperial Valley. and Las Vegas. Nevada,
including surrounding cities.

Plumbing contractors and appliance dealers
serving each of the above areas were
contacted to provide estimates of average
lifetimes for various plumbing fixtures and
water-related household appliances. These
8stimates enabled a distribution to be
constructed of average years of life by type of
plumbing fixtures and appliances. A statistical
analysis compared the estimated mean
lifetime of these items between subgroups of

~ Sixty years is considered the normal life of a housing
unit.

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