364
13.3.2 Colorado River (Texas) Basin
The Lower Colorado River Authority (LCRA) manages the allocation of water
within the Colorado River Basin in Texas. The LCRA operates the Highland lakes
(Lakes Buchanan and Travis) as a single system designed to supply water and
address varied interests within the LCRA’s service area.
Regarding their Water Management Plan (WMP), the Lower Colorado River
Authority states,
during drought, the plan requires the curtailment or cutback of interruptible stored water
from the Highland Lakes for downstream agriculture so that firm water supplies will be
available for the basic needs of cities, businesses, and industries. The plan also prescribes
how LCRA must provide water from the lakes to help meet the environmental needs of the
lower Colorado River and Matagorda Bay at various trigger points (Lower Colorado River
Authority (n.d).
The metrics here are water inflows into the lakes (ft
3
/s or acre-ft/month) and
environmental inflows into Matagorda Bay (cumulative flows over 1-, 3-, and
6-month spans).
Due to the 2011 drought, for the first time in its history, the LCRA had to invoke
the WMP to deny Colorado Basin rice farmers their allocations of irrigation water,
thus impacting the food component of the FEW nexus.
The Lower Colorado River Authority Water Management Plan has been a working document since its initial development in the late 1980s, with a summary of a
few of its metrics, rules, and definitions that allow it to effectively manage the water
basin and prescribe actions in the case of future droughts described here (Lower
Colorado River Authority 2014).
4
1. The WMP sets forth criteria for declaring a Drought Worse than Drought of
Record (DWDR) and includes a calculation of a metric known as the “Combined
Firm Yield” of Lakes Buchanan and Travis, which is the amount of water that
can be supplied annually from lakes Buchanan and Travis through repeat circumstances from the Drought of Record.
(a) Firm yield is defined as the amount of water that a reservoir could have
produced annually if it had been in place during the worst drought of record.
For the two main LCRA reservoirs (Lake Travis and Lake Buchanan), the
firm yield is a storage quantity of water currently set at 434,154 acre-ft/year
determined using hydrologic simulation from the TCEQ Water Availability
Model (Texas Commission on Environmental Quality 2018b). The Chap. 19
case study of the Great Lakes and St. Lawrence watershed shows that even
for a watershed with extremely large storages and flows of water, stakeholders
4 A full description is beyond the scope of this paper. The summary here is from the latest WMP,
and the differences from WMP active during the drought of 2011 are not material for this
discussion.
M. Carbajales-Dale and C. W. King
13.3.2 Colorado River (Texas) Basin
The Lower Colorado River Authority (LCRA) manages the allocation of water
within the Colorado River Basin in Texas. The LCRA operates the Highland lakes
(Lakes Buchanan and Travis) as a single system designed to supply water and
address varied interests within the LCRA’s service area.
Regarding their Water Management Plan (WMP), the Lower Colorado River
Authority states,
during drought, the plan requires the curtailment or cutback of interruptible stored water
from the Highland Lakes for downstream agriculture so that firm water supplies will be
available for the basic needs of cities, businesses, and industries. The plan also prescribes
how LCRA must provide water from the lakes to help meet the environmental needs of the
lower Colorado River and Matagorda Bay at various trigger points (Lower Colorado River
Authority (n.d).
The metrics here are water inflows into the lakes (ft
3
/s or acre-ft/month) and
environmental inflows into Matagorda Bay (cumulative flows over 1-, 3-, and
6-month spans).
Due to the 2011 drought, for the first time in its history, the LCRA had to invoke
the WMP to deny Colorado Basin rice farmers their allocations of irrigation water,
thus impacting the food component of the FEW nexus.
The Lower Colorado River Authority Water Management Plan has been a working document since its initial development in the late 1980s, with a summary of a
few of its metrics, rules, and definitions that allow it to effectively manage the water
basin and prescribe actions in the case of future droughts described here (Lower
Colorado River Authority 2014).
4
1. The WMP sets forth criteria for declaring a Drought Worse than Drought of
Record (DWDR) and includes a calculation of a metric known as the “Combined
Firm Yield” of Lakes Buchanan and Travis, which is the amount of water that
can be supplied annually from lakes Buchanan and Travis through repeat circumstances from the Drought of Record.
(a) Firm yield is defined as the amount of water that a reservoir could have
produced annually if it had been in place during the worst drought of record.
For the two main LCRA reservoirs (Lake Travis and Lake Buchanan), the
firm yield is a storage quantity of water currently set at 434,154 acre-ft/year
determined using hydrologic simulation from the TCEQ Water Availability
Model (Texas Commission on Environmental Quality 2018b). The Chap. 19
case study of the Great Lakes and St. Lawrence watershed shows that even
for a watershed with extremely large storages and flows of water, stakeholders
4 A full description is beyond the scope of this paper. The summary here is from the latest WMP,
and the differences from WMP active during the drought of 2011 are not material for this
discussion.
M. Carbajales-Dale and C. W. King