River Operations Report - Water Supply Operations

Summary

This River Report provides information about current river operations and conditions of the Colorado River and the Highland Lakes related to water supply operations.

When conditions warrant, the LCRA River Operations Control Center posts information about flood operations on the Flood Summary Report.

You can navigate to specific sections of the River 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: 9/16/2014 7:13 AM

Lakes Buchanan and Travis are the two water storage lakes in the Highland Lakes system, and supply water for more than 1 million people. LCRA relies on the natural flow of the Colorado River and water from the Highland Lakes to meet demands, consistent with all applicable water rights, regulations, and legal agreements including the 2010 Water Management Plan

Releases from Lake Buchanan will be made as needed through Buchanan, Inks, Wirtz and Starcke dams to replace a portion of the water taken by cities, power plants, evaporation and other uses along lakes Inks, LBJ and Marble Falls, and to replace a portion of the water that is released from Lake Travis.

Releases from Lake Travis will be made as needed to supply water to customers along Lake Austin, such as the City of Austin and the West Travis County Public Utility Agency, and to replace water that is released or evaporated from Lake Austin.

Releases from Lake Austin will be made as needed to supplement the natural flow of the Colorado River below Lake Austin in supplying water for customers downstream of the Highland Lakes and to replace water that is evaporated from Lady Bird Lake or lost in conveyance along the lower river.

In addition to passing through releases from upstream dams, water may be released from lakes Inks, LBJ, Marble Falls and Austin through Inks, Wirtz, Starcke, and Tom Miller dams, respectively, to pass through runoff from localized storms and inflows from tributary creeks and streams, as needed, to control the level of these lakes.



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)9/16/2014 12:15 PM 986.68 987.16988.71
Inks (Inks)9/16/2014 12:15 PM 886.99 887.19887.13
LBJ (Wirtz)9/16/2014 12:15 PM 824.65 824.67824.65
Marble Falls (Starcke)9/16/2014 12:15 PM 736.31 736.47736.32
Travis (Mansfield)9/16/2014 12:15 PM 622.73 623.21626.23
Austin (Miller)9/16/2014 12:15 PM 491.90 492.03491.88


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9/16/2014 7:00 AM
Short term lake level forecasts for Buchanan and Travis:

Tomorrow: Buchanan = 986.6 ft msl, Travis = 622.6 ft msl
One week: Buchanan = 986.2 ft msl, Travis = 622.0 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 9/16/2014 12:15 PM986.681,009.8823.2 875,588 310,098 35 % 565,490
Travis 9/16/2014 12:15 PM622.73663.1940.5 1,134,956 376,165 33 % 758,791
Total Combined Storage in Lakes Buchanan and Travis 2,010,544686,26334%1,324,281




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 9/16/2014 12:10 PM 23.0 201.035 21 41
Llano River at Llano 9/16/2014 12:12 PM 34.8 321.000 32 63
Sandy Creek near Kingsland 9/16/2014 12:25 PM 0.0 02.367 0 0
Pedernales River near Johnson City 9/16/2014 12:11 PM 5.0 62.030 11 22
Previous Day Total Gauged Inflows*    64126

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 9/16/2014 12:12 PM 262 287568
Colorado River at Bastrop 9/16/2014 12:26 PM 593 6451,279
Colorado River at Smithville 9/16/2014 12:27 PM 670 5451,080
Colorado River above La Grange 9/16/2014 12:27 PM 563 5301,051
Colorado River at Columbus 9/16/2014 12:25 PM 392 422837
Colorado River near Altair 9/16/2014 12:25 PM 404 436866
Colorado River at Wharton 9/16/2014 12:26 PM 227 107212
Colorado River near Lane City 9/16/2014 12:25 PM 210 93185
Colorado River at Bay City 9/16/2014 12:25 PM 616 480951

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)9/15: 2-5 pm306607
Inks (Inks)9/15: 2-5 pm389772
LBJ (Wirtz)9/15: 3-4 pm182361
Marble Falls (Starcke)9/15: 4-5 pm162321
Travis (Mansfield)9/15: 2-5 pm370734
Austin (Miller)9/15: 2-5 pm215426

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 46252 287
Colorado River at Bastrop  628120645
Colorado River at Columbus  396120422

On Jan. 1, 2014, the combined storage of lakes Buchanan and Travis was 764,341 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 2014.

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 36,865 14,260
February 23,816 14,260
March 45,960 14,260
April 18,694 14,260
May 186,259 14,260
June 59,721 14,260
July 19,303 14,260
August 8,353 14,260
September 14,260
October 14,260
November 14,260
December 14,260
Annual Total398,971171,120

The data in the table above shows monthly freshwater inflow volumes for 2014.On Jan. 1, 2014, the combined storage of lakes Buchanan and Travis was 764,341 acre-feet. In accordance with the Water Management Plan, because storage was less than 1.1 million acre-feet, environmental flow requirements for Matagorda Bay's freshwater inflow needs are set to critical levels in 2014. 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. This 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.




Long-Range Lake Level and Storage Forecasts (Links) Historical Data and Reports (Links) Useful Links
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