As we noted in our last post, a recent
Texas Court of Appeals ruling has highlighted the issue of Region C’s desire to
proceed with the proposed Marvin Nichols Reservoir in East Texas. This project,
which is proposed to supply approximately 450,000
acre feet/year at a capital cost of $ 3.3 billion. Marvin Nichols is one of eight Region C
projects that are in the top 20 most costly projects in the 2012 State Water
Plan. In fact, the 2012 Plan recommended
a total of $ 21 billion in water supply projects for Region C, or about 40% of
the total projected state plan cost of $ 53 billion by 2060. Many of these projects, especially the
proposed large new reservoirs and pipelines, are not projected to be needed
until near the end of the 50-year planning horizon.
These proposed Region C projects are driven by municipal
demand projections for the fast-growing Dallas-Fort Worth Metroplex. These demand projections have two components:
projected population and projected water use per capita, often expressed in
gallons of water per capita per day (or GPCD).
Both population and projected water use figures are developed in the
first instance by the Texas Water Development Board (TWDB). The regions are then given leeway to request
“adjustments” of both population and projected GPCD.
The demand
projections supplied to Region C by TWDB for the current new round of
planning are considerably lower than the projections used to develop the 2012
plan. In fact, as discussed below, using
the TWDB projections with the application of conservation strategies comparable
to that used in the 2012 Region C plan, would result in almost 600,000
acre-feet less municipal demand in 2060 (2.2 million acre-feet (MAF) vs.
the 2012 plan projection of 2.8 MAF), potentially completely eliminating
the need for Marvin Nichols or other projects, or at least pushing them out to
the very far end of the 50-year planning horizon.
These new, more realistic, demand projections are a vital
step by TWDB in the direction of a more sustainable water plan for Texas. Strong oversight and public engagement will
be necessary to ensure these realistic projections are not undermined during
the regional review process. And, in
fact, there is reason to believe, as explained below, that if all (not just
some) water user groups in Region C were to engage in aggressive efficiency and
drought management measures, could eliminate the need for an additional 400,000
acre-feet of new supply. This, in turn,
should result in a substantial reduction in the projected costs of the Region C
plan, and thus in the cost of the state plan as a whole.
___________________________
Discussion
Updated municipal demands are calculated based on population
forecasts supplied by the state demographer and on GPCD estimates. The population forecast tends to become less
accurate toward the end of the planning horizon, but a review of previous water
plans indicates that population projections compare well with actual growth. For example, census results showed that the
forecasts from 2006 overestimated 2010 population by only about 1 percent. The population forecast for the new 2017 plan
corrects for that difference and other region-specific factors.
Developing accurate and agreed upon GPCD projections is
substantially more complex and error-prone.
The first complication is the data.
Water use data in much of Texas is self-reported by retail or wholesale
water suppliers, and reports differ among different entities. The amount that
users report (buyers) may not always match the amount that wholesalers
(sellers) report. So, consultants who do
the leg work of developing regional plans spend a good part of their effort
resolving these discrepancies.
What is turning out to be a more controversial issue,
however, has been the decision on what annual water use to select for the base
year GPCD. The base year GPCD is
important because, after making some adjustments for the build-out of more
efficient plumbing fixtures, the base year demand defines the demand that will
be used for planning for future water needs through 2070. Because water use
varies significantly from year to year, selecting the appropriate base year is
critical. In some cities, particularly where no drought management measures are
applied, municipal use per capita may be higher in dry years than in wet
years. By contrast, where drought
management measures are employed in dry years, municipal use per capita will be
lower, though potentially still higher than in normal years.
Since the regional planning process is intended to meet
water needs during drought – water supply estimates are based on availability
during a repeat of the historical drought or record, which for most of the
state occurred in the 50’s – water planners at the Texas Water Development
Board selected a dry year, 2011, to represent base year demands.
The estimates of municipal demand used to develop the 2012
State Water Plan show that the baseline for Region C starts at 207 GPCD in
2010 and declines to 198 GPCD in 2060, as a result of reduction from federally
mandated plumbing fixture efficiencies. The 2011 Region C planning group also
recommended basic and advanced water conservation strategies for individual
water user groups. These water supply
strategies further reduced the projected per capita use to 201 GPCD in 2010 and
178 in GPCD in 2060. With a Region C population estimated at about 6.6 million
people and growing to 13.0 million in 2060, this resulted in total municipal
demands of approximately 1.5 MAF in 2010 growing to 2.8 MAF in 2060.
However, the initial demand estimates provided to Region C
by TWDB for development of the 2017 plan are substantially lower than
those used for developing the 2012 plan.
The base GPCD for 2010 is 176 which, again, as the result of plumbing
code upgrades, declines to 161 in 2060.
Although it is too soon in the planning process to know what
Region C or other regions will do with respect to water conservation
strategies, if we assume that a comparable level of savings will be proposed in
this round, the GPCD can be expected to be revised down to about 169 in 2010
and 141 in 2060. Moreover, population
projections for the 2017 Region C plan are about 3% lower at the beginning and
end of the planning horizon (2020 and 2060) and about 6% lower in the middle
decades as compared with the estimates developed in the last round. These estimates, combined with the 169/141
GPCD values, would result in total municipal demands of approximately 1.2 to 2.2 MAF in 2060, or more than a 20
reduction in municipal water demand estimates for Region C.
The per capita water use reductions in Region C represent an
important step in the right direction towards meeting long term water needs and
one for which water suppliers and policy makers should be commended. It is also reflective of well documented
broader trends in decreased
per capita water use across the county, suggesting that this decreasing per
capita use trend, rather than the flat line forecasts (excluding adjustments
plumbing fixture improvements), should be incorporated in long term
projections. That said, it is worth asking whether even the use rates meet
sufficiently ambitious goals for municipal water use.
Texas Water Conservation Implementation Task Force (WCITF) recommended a goal of 140
GPCD for potable water supplied to municipal retail customers. The
discussion above suggests that Region C is on course towards that goal. There are several nuances to the WCITF target
that are worth considering. In support of Region C’s current forecasts, for
example, it should be noted that the 140 GPCD goal explicitly includes reuse as
part of the calculation. That is, before calculating the GPCD, demand should be
reduced by the amount of supply that is projected to be met through reuse of
existing supply. There is a significant amount of existing and planned reuse in
Region C, and so, by this calculation, the projected GPCD would be even
lower.
On the other hand, given that conservation is the most cost
effective, least environmentally destructive and overall most sustainable
strategy for meeting long term water needs, it is important to consider that
the WCITF 140 GPCD recommendation was the result of a long and difficult
negotiation to reach a broad consensus amount water suppliers, state agency
representatives and public and environmental advocacy groups. It does not necessarily represent a
particularly aggressive approach to conservation, nor is it reflective of the
best we can do with technological innovation, funding and education.
In fact, a minority report to the WCITF recommended a target
of 125 GPDC. Furthermore, even if the
140 estimate does represent a reasonable goal, it should be noted that this
target was intended for individual water user groups. As shown in Table 1, many of the Region C water
user groups whose needs were projected to be met by some of the very costly and
environmentally damaging projects proposed in the last state water plan still project
a GPDC well above 200.
Table 1: Large Water User Groups (Population > 30K) Supplied
by Wholesalers Proposing Large Reservoir Projects With High GPCDs
If these water user groups with high GPCDs were able to get their
individual use down to the compromise 140 GPCD value, this could result in
additional reduction of over 400,000 acre-feet/year in 2060 and a regional average
GPCD of about 130. This kind of
aggressive goal could make Region C a leader in the state (and the nation) in
showing how to meet future water demand in a cost-effective and sustainable
fashion.
Unfortunately, rather than an increased push towards more
conservation, some Regional Planning groups, apparently including Region C, may
try to push the pendulum back the other way.
The argument is that the new base GPCD projections supplied by TWDB are too
low because base demands in 2011 may reflect implementation of drought
contingency plans (reducing outdoor watering etc.)
Some have put forward the view that drought contingency
measures should be included in the water plan as “supply strategies” rather
than being reflected in baseline demands. They contend that drought contingency
plans will not be implemented unless they are budgeted and planned for, and
thus they should be included as water supply strategies.
Yet, Texas Law does require the development and
implementation of drought contingency plans.
Thus, it can be argued that these reductions are similar to those that
result from the mandatory plumbing code changes built into demand forecasts.
Moreover, if drought contingency plans are at least required
to be in the demand forecast, the projected gap between supply and demand will
be less, thus reducing the potential costs of meeting the gap. Unfortunately, the last Region C plan states that
drought contingency planning should not even be incorporated as a water supply
strategy: :
Drought
management and emergency response measures are important planning tools for all
water suppliers. They provide protection in the event of water supply
shortages, but they are not a reliable source of additional supplies to meet
growing demands. They provide a backup plan in case a supplier experiences a
drought worse than the drought of record or if a water management strategy is
not fully implemented when it is needed. Therefore, drought management measures
are not recommended as a water management strategy to provide additional
supplies for Region C.
If that position were adopted by TWDB and drought
contingency reductions were not included in the demands, the projected gap
between supply and demand would be inflated statewide, leading to a much more
expensive state plan.
Conclusion
The debate in Region C between TWDB and some who prefer to
use higher demand projections poses an important statewide issue. If the high demand approach is adopted b
other planning groups, it could result in more proposals for unnecessary and
controversial projects, bogging down the state plan in the type of conflicts
that have arisen between Regions C and D.
The benefits of drought contingency planning on lowering
demands for the planning process are clear. . The baseline demands used should reflect these
measures. Failure to include them would
mean that some water users will take on responsible demand reduction efforts,
and the political and economic costs associated with them, while others look to
state funding to help them build costly projects that may ultimately not be
needed. That is not a sustainable, or
equitable, approach to state water planning.