River Operations Report - Water Supply Operations

Summary

This River Operations Report provides information about LCRA's water supply operations.  Please see the Flood Summary Report for information about flood operations.

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: 11/22/2014 5:30 PM

HAZARDOUS WEATHER OUTLOOK

The National Weather Service (NWS) continues to forecast the chance for showers and thunderstorms for the Colorado River basin into early Sunday morning.  Some of these storms could be severe and produce an additional 1-3 inches of rainfall on the already wet ground.

For NWS updates see here:  http://www.srh.noaa.gov/ewx/

Unscheduled releases from the Highland Lakes dams may occur suddenly and unexpectedly due to emergency hydroelectric generation or to pass through runoff from localized storms and inflows from tributary creeks and streams, as needed, to control the level of lakes Inks, LBJ, Marble Falls, and Austin. Residents should exercise caution and avoid being in the water near the dams.



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)11/22/2014 9:00 PM 986.32 986.19986.37
Inks (Inks)11/22/2014 9:00 PM 887.07 887.25887.30
LBJ (Wirtz)11/22/2014 9:00 PM 824.49 824.68824.63
Marble Falls (Starcke)11/22/2014 9:00 PM 736.34 736.35736.38
Travis (Mansfield)11/22/2014 9:00 PM 622.28 622.25623.40
Austin (Miller)11/22/2014 9:00 PM 492.21 492.14492.05


Highland Lakes Profile Click to view dynamic Highland Lakes System Profile
Click to view webpage.


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11/22/2014 8:45 AM
Short term lake level forecasts for Buchanan and Travis:

Tomorrow: Buchanan = 986.1 ft msl, Travis = 622.0 ft msl
One week: Buchanan = 986.0 ft msl, Travis = 621.8 ft msl



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


(ft msl)
Historical
November
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 11/22/2014 9:00 PM986.321,010.8124.5 875,588 305,822 35 % 569,766
Travis 11/22/2014 9:00 PM622.28666.5344.3 1,134,956 372,443 33 % 762,513
Total Combined Storage in Lakes Buchanan and Travis 2,010,544678,26534%1,332,279




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 11/22/2014 8:55 PM 82.7 421.035 44 86
Llano River at Llano 11/22/2014 8:56 PM 131.3 621.000 62 124
Sandy Creek near Kingsland 11/22/2014 8:55 PM 1,194.1 12.367 2 3
Pedernales River near Johnson City 11/22/2014 8:56 PM 1,248.8 212.030 42 84
Previous Day Total Gauged Inflows*    150297

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 11/22/2014 8:56 PM 2,300 68135
Colorado River at Bastrop 11/22/2014 8:55 PM 322 217430
Colorado River at Smithville 11/22/2014 8:56 PM 430 235466
Colorado River above La Grange 11/22/2014 8:55 PM 507 238473
Colorado River at Columbus 11/22/2014 8:55 PM 307 237470
Colorado River near Altair 11/22/2014 8:55 PM 301 318630
Colorado River at Wharton 11/22/2014 8:55 PM 252 318630
Colorado River near Lane City 11/22/2014 8:55 PM 297 371737
Colorado River at Bay City 11/22/2014 8:55 PM 969 6521,294

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)11/21: 5-6 am57113
Inks (Inks)11/21: 5-6 am51101
LBJ (Wirtz)11/21: 5-8 am5311,053
Marble Falls (Starcke)11/21: 5-6 am, 7-9 am5351,061
Travis (Mansfield)11/21: 2-4 pm, 5-6 pm115228
Austin (Miller)11/21: 5-6 am3161

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 4663 68
Colorado River at Bastrop  211120217
Colorado River at Columbus  224120237

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 32,164 14,260
October 16,909 14,260
November 14,260
December 14,260
Annual Total448,044171,120

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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