of Remarks by Ken Kramer, Director, Lone
Star Chapter of the Sierra Club, to the House
Natural Resources Committee at its Interim Hearing in San
Antonio on March 9, 2010.
March 9, 2010
Briefing Paper on Drought Management Plan Triggers and Stages
Texas weather has sometimes been described as drought punctuated by floods. That may be an overstatement, but undoubtedly the state has experienced a number of regional or statewide droughts over the decades. At times those droughts are broken by major rainstorm events resulting from tropical storms or the effects of El Nino. The reality is, however, that Texas is no stranger to droughts, some of which â€“ such as the historic drought of the 1950s â€“ have been prolonged and widespread and not always easily broken.
This reality was recognized in a very important provision of the landmark Senate
Bill 1 enacted by the Texas Legislature in 1997 in part in response to the drought of 1996 and the recognition by state leaders such as then Lt. Governor Bob Bullock that the state needed to be better prepared to deal with droughts. The provision noted was a
requirement that certain water right holders to prepare and
submit to the State of Texas a drought contingency plan. That requirement was modified by subsequent legislation in 2003 and 2007 to include mandates for quantifiable water use reduction targets in those drought contingency plans and for annual reports on the implementation of the plans as well as to require more retail water suppliers to prepare those plans.
Although current statutes do not prescribe specific components or specific water use reduction targets of these drought contingency plans nor require a substantive review of the plans by a state agency, the State of Texas does have a stake in how well-crafted and effective these drought contingency plans are. Since regional and state water planning is aimed at meeting water needs during a drought as severe as the historic drought of record, these drought contingency plans and their implementation need to be factored into the projections for available water supplies, water demands, and proposed water management strategies in the regional and state water plans.
Some projected water â€śshortagesâ€ť identified in regional and state water planning might be met by the attainment of reasonable reductions in non-essential water uses through implementation of drought contingency plans. That argues for a closer look at some elements of these drought plans, including the effectiveness of triggers for the initiation of drought management activities at different stages of the plans.
Basic Components of a Drought Management Plan
Most drought contingency or drought management plans (the terms are interchangeable) have certain basic components, including but not limited to a number of stages based on the severity of a drought or the anticipation of a deepening drought. Characteristically these stages specify different actions (voluntary or mandatory) to be taken at the respective stages to try to reduce water use in order to stretch existing water supplies in a time of low or no rainfall. In wetter times rainfall would be expected to replenish those water supplies (be they surface rivers and lakes or aquifers with significant recharge capacity), and normal water use patterns would likely prevail. The number of stages in a drought management plan varies widely, but most plans appear to be characterized by three to five stages, with different and increasing levels of water use reduction at each stage to match the growing severity of drought conditions.
Each stage in a drought management
plan has a specific â€śtriggerâ€ť level that initiates the actions
required or suggested at that stage. These triggers relate to â€śdrought indicators,â€ť
which define when a drought is occurring or perhaps anticipated.
As these indicators demonstrate that a drought is worsening,
trigger levels in each stage of a drought management plan
attempt to mirror those changes in drought intensity and
adjust drought contingency measures accordingly.
There several types of drought triggers that might be chosen
to put into effect different stages of a drought management
plan. Generally they are based on one or more of the following
measurements or combinations thereof:
(1) Drought Indices â€“ There are a number of national drought
indices that are based on such factors as precipitation,
soil moisture, crop moisture, surface water measurements,
and various other factors and combinations of factors. Examples
are the Standardized Precipitation Index (SPI), the Palmer
Drought Severity Index (used by many government agencies),
the Surface Water Supply Index (used by the state of Colorado),
and the Reclamation Drought Index (used by the Bureau of
Reclamation and Oklahoma). The Texas Water Development Board
(TWDB) makes periodic reports to its governing board using
information from the National Drought Mitigation Center at
the University of Nebraska-Lincoln to describe drought conditions
in Texas and elsewhere in the country.
(2) Reservoir Storage â€“ Many water suppliers whose primary
or sole source of supply is a surface water reservoir (or
reservoirs) use reservoir storage levels to determine if
and when drought contingency measures need to be implemented.
(3) Streamflow Conditions â€“ Information about the volume
and velocity of flows in rivers and streams may be used to
determine the effects of low rainfall conditions and as triggers
for implementation of drought contingency measures.
(4) Groundwater Levels â€“ Groundwater levels may be used to
decide if drought contingency measures should be implemented
by water suppliers primarily dependent upon aquifers as their
water source, especially in areas where aquifer levels fluctuate
considerably as a result of rainfall and related recharge.
As noted, two or more of these drought triggers or some other
variation of them might be used in combination, of course,
in a specific drought management plan. The Edwards Aquifer
Authority (EAA), for example, uses a combination of indicator
well levels and springflow conditions in its drought management
plan. A summary of the water use reduction goals at individual
stages and the associated trigger levels for those stages
in the drought management plans for five municipal water
suppliers in Texas: Austin, Dallas, Houston, Lubbock, and
San Antonio is attached as an appendix to this briefing paper.
This overview demonstrates the variability of water use reduction
goals and triggers at each stage of the respective plans.
It is probably a truism that there
is no one right approach to choosing drought indicators and
triggers or defining stages in a specific drought management
plan. To a great extent
the selection of appropriate stages and triggers must be
based on a variety of factors specific to a wholesale or
retail water supplier, including the source of its water
supplies. The choice of drought triggers for each stage of
a plan may have significant consequences, however, for how
quickly and effectively a drought management plan and its
staged reductions in water use might be implemented and the
extent to which its implementation might avoid the need for
extreme measures before the drought is broken.
Some Cases in Point
One illustration of the issue of choosing
appropriate triggers for a drought management plan comes
from recent experiences in the Central Texas area. The years 2008 and 2009 were some
of the hottest and driest on record in Central Texas, with
extremely high temperatures in 2009. Beginning in the summer
of 2008 Central Texas was categorized as being in â€śextremeâ€ť
or â€śexceptionalâ€ť drought â€“ the worst two categories â€“ where
it remained until the fall of 2009 when rain events associated
with the impacts of El Nino began to break the drought.
Rainfall and water flowing into Central Texas lakes were
at record lows during 2008 and 2009, and the impact of those
factors on lake levels was dramatic. Lakes Travis and Buchanan,
managed by the Lower Colorado River Authority (LCRA), were
full in the fall of 2007 (the two lakes are full at a combined
2.011 million acre-feet). By the end of summer 2009, however,
the water supply reservoirs were at about 39 percent of combined
Under the LCRA drought contingency plan in effect at the
time, LCRA did not ask its customers to implement drought
management measures until August 12, 2009, when the combined
reservoir storage fell to 900,000 acre-feet. Thatâ€™s because
the LCRA drought contingency plan, recently tweaked, uses
reservoir levels â€“ specifically the combined capacity of
Lakes Travis and Buchanan â€“ as the triggers for the implementation
of various stages of the plan. Specifically the 900,000 acre-foot
combined capacity was the trigger in the plan for LCRA to
ask its customers to implement drought management measures.
[It should be noted that under the LCRA drought contingency
plan, actions such as a request for implementation of voluntary
drought management measures and possible curtailment of reservoir
releases for downstream environmental flows or downstream
interruptible irrigation rights come at earlier reservoir
One could argue that by the time the 900,000 acre-foot trigger
was reached in August 2009, with summer nearly over, a huge
opportunity for water savings had been lost because drought
management measures were not implemented earlier. In most
Texas cities, water use dramatically increases during the
summer because of outdoor landscape watering. Possibly LCRA
should have structured their drought contingency plan to
implement drought management measures when the water service
area was determined by the National Drought Management Center
to be in an extreme or exceptional drought instead of relying
on reservoir levels as triggers for initiating action.
The discussion of this particular situation is not intended
to be critical of LCRA or focus on just one type of drought
contingency plan triggers. It is simply to raise the question
of whether Texas â€“ a drought prone state â€“ should take a
closer look at the triggers, the stages, and the other components
of drought contingency plans used by Texas water suppliers
to determine which might comprise the most effective drought
management plans for those water suppliers.
Recently the consultants to the Region
H Water Planning Group(Region H includes the San Jacinto River Basin and a part
of the lower Trinity and lower Brazos River Basins) undertook
a study of whether drought management should be considered
as a water management strategy in the Region H plan. They
concluded that it should not even though regional water planning
is aimed at meeting or managing water demands in a drought
as severe as the drought of record and even though drought
contingency plans should certainly be in effect during a
drought of record.
However, their conclusion was based
solely on looking at a few water suppliers in the region
that used reservoir levels as their drought contingency plan
triggers. The consultants never considered whether other
drought contingency plan triggers should be recommended to
enhance the ability to use drought management as a regional
water management strategy. The failure
to do so artificially limited the possibility of meeting
a portion of water demands for the region through effective
The Texas Water Development Board (TWDB) should undertake
a thorough and adequately-funded study to be conducted by
its staff and/or appropriate contractors to evaluate the
effectiveness of a random sample of drought contingency plans
currently used by water suppliers in Texas â€“ looking at the
drought management plan stages, the triggers for each stage,
actions specified at each stage, and water use reductions
achieved by implementation of those plans. The results of
that evaluation and any subsequent recommendations should
be provided to the water supply community, regional water
planning groups, and Texas state officials with the goal
of enhancing effective use of drought management as a strategy
to meet water demands in times of drought.