point of considerable controversy. However, 
recent research appears to confirm that reversal to 
some degree is possible. 
Therefore, in summary, if present resource 
management practices are not improved, Lake Erie 
will continue to accelerate toward its demise, and 
the other Lakes will likely succumb in the order: 
Ontario, Michigan, Huron, and Superior. If only 
preventive measures are taken, Lake Erie may 
recover in a few thousand years, and water quality 
in other Lakes will be maintained; Lake Ontario 
also may show improvement. If both preventive 
and restorative measures are implemented, marked 
improvement in Lake Erie might be observed 
within a generation. 
These statements, however, are far too general 
to support the necessity for restoration. The 
question, “What is the desired level of water 
quality in the Great Lakes?” has never been 
specifically answered. The objective should be to 
optimize the benefits which would accrue because 
of enhanced water quality in terms of the cost of 
attaining such enhancement. 
Within the general framework of a market 
system, there are clear-cut reasons to suppose that 
public intervention can control disposal of wastes 
into water bodies. Not only can government 
intervention improve efficiency as measured in 
terms of market values, but it can and should take 
explicit cognizance of extra-market values. Since 
the character of water courses in heavily populated 
areas is such that interdependency between uses is 
inevitable, a major problem confronting public 
policy is to gauge accurately the significance of 
various interdependencies and foster the efficient 
multipurpose use of the water resource. 
The answer, then, to the question of how much 
restoration is enough can be determined through a 
detailed benefit-cost analysis similar to that which 
long has been used to evaluate the economic 
feasibility of large public projects. 
Figure 49 illustrates the type of analysis re- 
quired. At the outset, the costs of improved water 
quality probably will not be matched by the value 
of associated benefits. Eventually, the value of 
benefits will rise until incremental benefits equal 
incremental costs (Point A). Benefits will exceed 
costs from A to B, but the ratio will gradually 
decrease until the incremental benefits are again 
equal to incremental costs (Point B). Beyond that 
point, increments of cost will exceed increments 
VI-130 
of benefit. Hence, Point B is commonly referred to 
as the most economically efficient project scale, 
because this point maximizes benefits in terms of 
associated costs. 
Ue - BENEFITS=COSTS 
BENEFITS 
COSTS Cc 
Figure 49. Benefit-cost analysis. 
Since the degree of restoration can be directly 
implied from the derived optimum cost (Point C), 
a detailed benefit-cost analysis can identify how 
much restoration is enough. 
Several benefits that can be quantified: 
—Enhancement of land values. 
—Reduced cost of water treatment for domestic, 
municipal, and industrial supplies. 
—Enhancement of the fishery resource, both 
commercial and sport. 
—Enhancement of water-based recreation activities 
and increased potential for water-based recreation 
opportunities. 
—Minimized potential public health hazard. 
—Improved aesthetic appeal of the Lakes and 
attraction of tourists. 
Benefits derived from improved water quality 
change continually. For example, demographic 
and sociological trends as in increased population, 
leisure time, income, and mobility will put in- 
