Trigger points: How LCRA prioritizes water during
LCRA's state-approved Water
Management Plan is designed to prioritize water during droughts based
on the combined storage of lakes Travis and Buchanan. The lower the water
drops, the stronger the actions required to limit water use. Follow the link below to see the specifics:
2010 Drought Triggers
Terms to know
*Acre-foot: The amount of water required to cover an area of
one acre to a depth of one foot. One acre-foot of water is equal to almost
Drought of record: The decade-long drought that affected
Central Texas from the late 1940s through the late 1950s. (See
LCRA history.) No other drought in recent history was as sustained. LCRA and other organizations use it as a benchmark to compare recent
droughts and to prepare for future droughts.
Firm water: The amount of water lakes Buchanan and Travis could
supply during a repeat of the most severe drought on record. Most of this water
is committed for use by cities, industries, power plants and protection of
Interruptible water: Water that is available for use on a
year-to-year basis, depending on how much water is stored in lakes Travis and
Buchanan. Interruptible water is subject to curtailment during water shortages.
Mean sea level (msl): A point of reference to measure lake
elevation. It refers to the elevation of the ocean halfway between high and low
tide. Lake elevations are measured in feet above mean sea level.
Note on calculations: The volume of water
in the lakes shifts constantly
because of the build-up of sedimentation, changes in river channels and other
factors. The calculations above are based on the latest hydrological surveys
Lake Buchanan’s volume is from an LCRA hydro survey in 1991 plus aerial
mapping in 1997 (based on
National Geodetic Vertical Datum of 1929). Lake
Travis’ is from an LCRA hydro survey in 1992-1993 and aerial mapping
in 1997 (NGVD 29).