2008 report of the water allocation study of the NC Environmental Review Commission

              2008 Water Allocation Study Team Report 15
communities’ ability to grow and prosper.
Others believe that water availability within
a given basin should be viewed as a limit
on growth in that basin. Still others believe
that allowing easy transfers encourages
communities to waste water and to avoid
enacting efficiency and conservation
measures that would be more sustainable
ways to supply water.
However, views about interbasin transfer
tend to be driven by assumptions about what
those transfers are like, and the assumptions
are not always grounded in fact. The NC
Chapter of the American Waterworks
Association ( AWWA) produced a white
paper on interbasin transfers on December
19, 2006, authored by Barry Gullet, PE, of
Charlotte- Mecklenburg Utilities, then chair
of the NCAWWA. This is a good summary
of how past and current IBTs in North
Carolina actually work.
Although IBT permits need to be
reviewed comprehensively, there can be
clear benefits to allowing these transfers,
and it is possible that the complexity of the
certification process discourages beneficial
transfers. Specifically, transfers can increase
water supply reliability, delay the need for
building reservoirs and treatment plants,
and reduce environmental impacts.
Water supply reliability can be increased
and costs reduced by the cooperation of
water utilities entering into water transfer
agreements, such as interconnects, that take
advantage of variability in excess capacity
and in supply and water usage patterns
between the water systems. This variability
may be higher in systems in different basins
compared to ones in the same basin because
of geographical differences in land use and
weather. As a result, IBTs may allow even
greater benefits.
Structurally augmenting supplies ( e. g.,
reservoirs, wells) is becoming increasingly
costly while also imposing unpopular
environmental impacts ( Gleick 2000;
NRC 2001). A given geographical region
will likely have a limited number of
viable supply- enhancement options. This
is particularly true in the fast- growing
headwaters regions of North Carolina’s
Piedmont. It can be economically and
environmentally beneficial to develop the
best option and share it with neighboring
systems, even those in other basins, to
prevent development of more expensive
systems in more environmentally sensitive
areas.
IBTs are typically requested to meet
projected ongoing demand, and once the
IBT certificate has been granted, utilities
can withdraw up to the allotted amount
given they meet the other conditions of the
certificate, which may include implementing
drought- management measures during
times of drought. Conditional withdrawals
are another option that preserve much
of the gains in reliability and cost while
minimizing total transfers. Work with
interconnects ( Palmer 2006) between
three utilities in North Carolina’s Triangle
area shows that by allowing transfers only
under certain conditions ( a utility having
fewer than a specified number of days of
supply remaining or having a risk of failure
above a certain level), the volume of water
transferred is reduced by 60% to 80% over
a simple daily transfer cap. Although this
work considered transfers of finished water
between communities, it should also apply
to transfers of raw water.
The IBT certificate process has its
own costs that make it more difficult for
systems, especially small ones, to cooperate.
According to Tom Fransen, River Basin