River Operations Report - Water Supply Operations

Summary

This report provides current information about LCRA's daily water supply operations. 

LCRA posts the latest information about flood operations in the Flood Summary report when conditions warrant.

You can navigate to specific sections of the River Operations Report using the links below:

Data presented on this web page includes provisional data obtained by LCRA for the use of its professional staff. This data is retrieved and displayed automatically, and is subject to revision.

Current Operations and Conditions
Last Update: 9/4/2015 7:02 AM

In order to preserve the water supply, LCRA - with permission from the state - cut off Highland Lakes water to most interruptible water customers in 2012, 2013 and 2014.  In July 2015, the Texas Commission on Environmental Quality (TCEQ) approved emergency drought relief again for the remainder of the 2015 growing season.

Water supply operations are conducted consistent with all applicable water rights and agreements.  During water supply operations, needs for water are first met with the natural flow of the Colorado River - to the extent allowable - to reduce the amount of water used from the Highland Lakes.  Water may also be released from any of the Highland Lakes as needed to manage excess flood waters.

Releases from Lake Austin are made when needed to meet downstream customer needs, and to supplement the natural flow of the lower river for environmental flow requirements.  Customers that take water from the Colorado River downstream of Lake Austin include Fayette Power Project, industrial customers in Matagorda County, the City of Pflugerville, Decker Creek Power Station, Lost Pines Power Park and others.  Environmental flow requirements include TCEQ requirements to maintain instream flows along the lower Colorado River and supply freshwater inflows to Matagorda Bay and estuary.

Releases from Lake Travis are made when needed to replace water that is released from Lake Austin, and to supply water to customers along Lake Austin.  Customers that take water from Lake Austin include the City of Austin, West Travis County Public Utility Agency and others.

Releases from Lake Buchanan are made when needed to replace a portion of the water that is taken or released from Lake Travis, and to supply water to customers along lakes Inks, LBJ, and Marble Falls.  Customers that take water from the Highland Lakes above Mansfield Dam include the City of Austin, City of Cedar Park, Travis County WCID No. 17, City of Leander, Lakeway MUD, Ferguson Power Plant and others.



Current Lake Levels
Lake (Dam)Date/Time of Last ReportLake Level
(ft msl)
7 Days Ago
(ft msl)
30 Days Ago
(ft msl)
Buchanan (Buchanan)9/5/2015 7:00 AM 1006.42 1006.601007.27
Inks (Inks)9/5/2015 7:00 AM 887.24 887.26887.33
LBJ (Wirtz)9/5/2015 7:00 AM 824.66 824.68824.68
Marble Falls (Starcke)9/5/2015 7:00 AM 736.31 736.36736.30
Travis (Mansfield)9/5/2015 7:00 AM 667.85 668.35670.06
Austin (Miller)9/5/2015 7:00 AM 492.09 492.14492.05


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9/4/2015 6:45 AM
Short term lake level forecasts for Buchanan and Travis:

Buchanan
Tomorrow = 1006.4 ft msl
One Week = 1006.2 ft msl

Travis
Tomorrow = 667.8 ft msl
One Week = 667.4 ft msl




Current Storage In Lakes Buchanan and Travis
LakeDate/Time
of Last Report
Lake Level


(ft msl)
Historical
September
Average
(ft msl)
Difference
From
Average
(ft)
Storage
When Full

(Ac-Ft)
Current
Storage

(Ac-Ft)
Current
Percent
Full
%
Difference
From Full

(Ac-Ft)
Buchanan 9/5/2015 7:00 AM1,006.421,009.57-3.2 875,588 599,585 68 % -276,003
Travis 9/5/2015 7:00 AM667.85662.645.2 1,134,956 903,245 80 % -231,712
Total Combined Storage in Lakes Buchanan and Travis 2,010,5441,502,83075%-507,715




Upstream Flow Conditions and Gauged Inflows
LocationDate/Time
of Last Report
Current Flow


(cfs)
Previous Day
Average Flow

(cfs)
Inflow Runoff
Factor
Previous Day
Adjusted
Average Flow
(cfs)
Previous Day
Gauged Inflow
Volume
(Ac-Ft)
Colorado River near San Saba 9/5/2015 7:10 AM 18.0 191.035 20 39
Llano River at Llano 9/5/2015 7:10 AM 56.3 521.000 52 104
Sandy Creek near Kingsland 9/5/2015 7:10 AM 0.2 02.367 1 1
Pedernales River near Johnson City 9/5/2015 7:10 AM 3.4 32.030 7 14
Previous Day Total Gauged Inflows*    80158

Inflows to the Highland Lakes are measured at four streamflow gauges shown in the table above. A runoff factor is applied to the measured flow to account for additional inflows that may occur downstream of each gauge. When the natural flow of the Colorado River upstream of the Highland Lakes is abundant, LCRA stores the excess water in the Highland Lakes, and lake levels rise.


Downstream Flow Conditions
LocationDate/Time
of Last Report
Current Flow

(cfs)
Previous Day
Average Flow
(cfs)
Previous Day
Flow Volume
(Ac-Ft)
Colorado River at Austin 9/5/2015 7:10 AM 144 157311
Colorado River at Bastrop 9/5/2015 7:10 AM 318 327648
Colorado River at Smithville 9/5/2015 7:10 AM 289 317628
Colorado River above La Grange 9/5/2015 7:10 AM 334 316627
Colorado River at Columbus 9/5/2015 7:10 AM 346 348690
Colorado River near Altair 9/5/2015 7:10 AM 438 428849
Colorado River at Wharton 9/5/2015 7:10 AM 176 173343
Colorado River near Lane City 9/5/2015 7:10 AM 236 237470
Colorado River at Bay City 9/5/2015 7:10 AM 495 6841,356

Note: The U.S. Geological Survey's (USGS) Bay City Gauge is strongly affected by tides from the Gulf of Mexico and provisional gauge readings may be inaccurate when flow in the river at Bay City is low, below about 2,000 cfs.  Provisional data is subject to revision by the USGS.




Previous Day Releases
Lake (dam)Approximate
Time of Release
Average
Discharge
(cfs)
Discharge
Volume
(Ac-Ft)
Buchanan (Buchanan)9/3: No releases00
Inks (Inks)9/3: No releases00
LBJ (Wirtz)9/3: No releases00
Marble Falls (Starcke)9/3: No releases00
Travis (Mansfield)9/3: 12-5 pm464920
Austin (Miller)9/3: 4-5 pm4997

The Average Discharge and Discharge Volume data in the table above are average daily flows and volumes discharged through hydroelectric generation at each dam.  At times, generally during flood operations or when hydroelectric generating units are out of service, additional water may be released through spillways or floodgates. 

The schedule for today’s hydroelectric generation is competitive electric market information, and is not available to the public. Water may be discharged suddenly and unexpectedly due to emergency hydroelectric generation or other reasons. Residents should exercise caution and avoid being in the water near the dams.

(Releases from Lady Bird Lake through Longhorn Dam are controlled by Austin Energy, the electric utility for the City of Austin.)



Instream Flow Conditions and Environmental Criteria
LocationCriteria
for Minimum
Flow
(cfs)
Previous Day
Minimum
Flow
(cfs)
Criteria
for Average
Flow
(cfs)
Previous Day
Average Flow

(cfs)
Colorado River at Austin 46121 157
Colorado River at Bastrop  308120327
Colorado River at Columbus  335120348

On Jan. 1, 2015, the combined storage of lakes Buchanan and Travis was 689,396 acre-feet. In accordance with the Water Management Plan, because storage was less than 1.4 million acre-feet, environmental flow requirements for instream flow are set to critical levels in 2015.

Critical instream flow levels are a minimum flow of at least 46 cubic feet per second (cfs) in the Colorado River at Austin, and an average flow of at least 120 cfs in the Colorado River from Bastrop to Eagle Lake, upstream of Wharton.




Freshwater Inflows to Matagorda Bay
MonthMonthly Inflow*
(Ac-Ft)
Monthly Criteria
(Ac-Ft)
January 113,444 14,260
February 44,833 14,260
March 262,955 14,260
April 198,810 14,260
May 781,779 14,260
June 569,905 14,260
July 77,400 14,260
August 21,303 14,260
September 14,260
October 14,260
November 14,260
December 14,260
Annual Total2,070,429171,120

The data in the table above shows monthly freshwater inflow volumes for 2015.  On Jan. 1, 2015, the combined storage of lakes Buchanan and Travis was 689,396 acre-feet.  In accordance with the Water Management Plan, because storage was again less than 1.1 million acre-feet, environmental flow requirements for Matagorda Bay's freshwater inflow needs are set to critical levels in 2015.

At critical levels, the Water Management Plan requires LCRA to maintain monthly inflows of at least 14,260 acre-feet in the Colorado River at Bay City in all months.  The requirement is subject to the availability of inflows to the Highland Lakes in excess of senior water rights.

*Freshwater inflows to Matagorda Bay are measured at the U.S. Geological Survey's (USGS) Bay City gauge. However, this gauge is strongly affected by tides from the Gulf of Mexico and provisional gauge readings may be inaccurate when flow in the river at Bay City is low, below about 2,000 cfs. Provisional data is subject to revision by the USGS. At these low river flows, LCRA uses data from the Lane City gauge to determine the amount of freshwater flowing into the bay. The Lane City gauge is upstream of the Bay City gauge and is not influenced by tide. When determining freshwater inflows to the bay using the Lane City gauge, LCRA subtracts the water diverted from the river downstream of the Lane City gauge but upstream of the Bay City gauge. The monthly inflow volumes at the Bay City gauge, as determined by LCRA, are displayed above.




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