River Operations Report - Water Supply Operations

Summary

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

LCRA will lower lakes LBJ and Austin for about six weeks beginning Jan. 2, 2017.  Lake LBJ will be lowered about 4 feet, and Lake Austin will be drawn down about 10 feet.  For more information on the planned lake lowering of lakes LBJ and Austin, see lcra.org/lakelowerings.

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: 12/3/2016 8:26 AM

LCRA’s operation of the Highland Lakes is governed by the 2015 Water Management Plan.

The plan, approved by the Texas Commission on Environmental Quality in November 2015, protects the water supply for firm customers – mainly cities and industrial users – and allows LCRA to quickly adapt its operations as drought conditions change. The plan establishes three sets of operating conditions to determine the availability of interruptible stored water, which is primarily used by agricultural customers in Colorado, Wharton and Matagorda counties. It also sets two dates – March 1 and July 1 – for determining the amount of interruptible stored water available for first and second crop.

Under the 2015 Water Management Plan, a limited amount of interruptible stored water was available for first crop agricultural uses in the lower basin from mid-March through about mid-August in 2016. This was the first time Highland Lakes water had been available for most interruptible water customers since 2011.  The managed storage of lakes Buchanan and Travis on July 1 was 1,964,073 acre-feet.  Based on this water supply condition, additional water was made available for second crop through mid-October. The water was released gradually and only to the extent the needs for agriculture was not met with the natural flow of the Colorado River. The needs for agriculture and the flow of the river depended on weather conditions during the irrigation season.

LCRA conducts water supply operations consistent with the Water Management Plan and all other 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 also may 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 flow of the lower river when needed to meet environmental flow requirements.  Customers that take water from the Colorado River downstream of Lake Austin include four irrigation systems (the Lakeside, Garwood, Pierce Ranch and Gulf Coast systems), the 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)12/4/2016 2:00 AM 1017.96 1017.991018.02
Inks (Inks)12/4/2016 2:00 AM 887.18 887.28887.33
LBJ (Wirtz)12/4/2016 2:00 AM 824.59 824.66824.46
Marble Falls (Starcke)12/4/2016 2:00 AM 736.39 736.41736.34
Travis (Mansfield)12/4/2016 2:00 AM 681.36 681.15680.36
Austin (Miller)12/4/2016 2:00 AM 492.06 491.96491.94
Bastrop (Bastrop)12/4/2016 1:55 AM 448.44 448.03448.19


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


Subscribe to the Daily River Report

12/03/2016 8:00 AM
Short term lake level forecasts for Buchanan and Travis:

Buchanan
See the Flood Operations Report for lake level forecasts on Buchanan

Travis
See the Flood Operations Report for lake level forecasts on Travis




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


(ft msl)
Historical
December
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 12/4/2016 2:00 AM1,017.961,010.317.7 875,588 831,021 95 % -44,567
Travis 12/4/2016 2:00 AM681.36666.3015.1 1,134,956 1,141,929 101 % 6,973
Totals 2,010,5441,972,95098%-37,594

Lake Buchanan is currently being managed to a maximum storage level of 1,018 feet msl.  Under an agreement with the Federal Emergency Management Agency, conservation storage is limited to this elevation in the more flood-prone months of May through October.  LCRA is currently limiting storage year-round while upgrades to the floodgates are underway. Read more about the management of Lake Buchanan.



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 12/4/2016 1:55 AM 157.1 1531.035 159 315
Llano River at Llano 12/4/2016 1:55 AM 248.7 2081.000 208 413
Sandy Creek near Kingsland 12/4/2016 1:55 AM 205.7 782.367 184 366
Pedernales River near Johnson City 12/4/2016 1:55 AM 131.8 952.030 193 384
Previous Day Total Gauged Inflows*    7441,478

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 12/4/2016 1:55 AM 360 8371,660
Colorado River at Bastrop 12/4/2016 1:55 AM 1,086 1,0332,049
Colorado River at Smithville 12/4/2016 1:55 AM 1,960 1,3312,640
Colorado River above La Grange 12/4/2016 1:55 AM 4,464 2,3094,580
Colorado River at Columbus 12/4/2016 1:55 AM 1,665 1,1862,353
Colorado River near Altair 12/4/2016 1:55 AM 1,269 1,2302,440
Colorado River at Wharton 12/4/2016 1:55 AM 1,472 1,5513,077
Colorado River near Lane City 12/4/2016 1:55 AM 1,480 1,5313,036
Colorado River at Bay City 12/4/2016 1:55 AM 2,354 2,2884,538

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 2,300 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)12/02: No releases00
Inks (Inks)12/02: 10-11 am81161
LBJ (Wirtz)12/02: Noon-1 pm, 3-7 pm9541,892
Marble Falls (Starcke)12/02: 1-2 pm, 4-8 pm1,0292,041
Travis (Mansfield)12/02: 11 am-2 pm,408809
Austin (Miller)12/02: Noon-4 pm393780

The Average Discharge and Discharge Volume data in the table above are average daily flows and volumes discharged at each dam. 

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
Daily Average
Flow
(cfs)
Previous Day
Average Flow

(cfs)
Colorado River at Austin 50216N/A837
Colorado River at Bastrop 3158504501,033
Colorado River at Columbus N/A 7371,186
Colorado River at Wharton N/A 7461,551

On July 1, 2016, the daily average combined storage of lakes Buchanan and Travis was greater than 1.96 million acre-feet. In accordance with the 2015 Water Management Plan, environmental flow requirements for instream flow are set to Base-Average levels from July 2016 through February of 2017.  The 2015 WMP prescribes daily average flow criteria at Bastrop, Columbus and Wharton and minimum flow values at Bastrop for Base-Average that vary from month to month, as shown above. 

LCRA’s obligation to release water from lakes Buchanan and Travis to help meet Base-Average instream flow levels is subject to the availability of inflows to lakes Buchanan and Travis in excess of senior water rights.  While the Base-Average criteria in effect is subject by the availability of inflows to the lakes Buchanan and Travis, LCRA will continue to meet Subsistence instream flow criteria, including the minimum flow criteria at Austin, using previously stored water if necessary. 


See Chapter 4 of the 2015 Water Management Plan for a more complete description of the instream flow criteria.




Freshwater Inflows to Matagorda Bay
MonthInflow
Category in
Effect
Criteria for
Monthly Inflow
(ac-ft)
Monthly Inflow*
(ac-ft)
Criteria for
Two-Month Inflow
(ac-ft)
Two-Month
Inflow
(ac-ft)
January OP-2 15,000 105,895 52,000315,841
February OP-2 15,000 60,782 52,000166,677
March OP-3 15,000 189,669 164,000250,451
April OP-3 15,000 680,586 164,000 870,255
May OP-3 15,000 811,658 76,0001,492,244
June OP-3 15,000 1,241,816 76,0002,053,473
July OP-4 15,000 101,401 205,0001,343,216
August OP-4 15,000 266,527 205,000367,928
September OP-4 15,000 95,195 133,000361,722
October OP-4 15,000 52,065 133,000147,149
November OP-4 15,000 135,679 133,000187,744
December OP-4 15,000 133,000 
Annual Total 180,0003,741,273  

The 2015 Water Management Plan describes five inflow categories for freshwater inflows to Matagorda Bay. The inflow category is determined by the amount of water stored in lakes Buchanan and Travis on March 1 and July 1. The lowest inflow category is “threshold”. Threshold category calls for minimum monthly inflows of 15,000 acre-feet. The higher inflow categories are “OP-1” through“OP-4”. The OP-1 through OP-4 categories call for minimum monthly inflows of 15,000 acre-feet, and higher two-month inflows that vary throughout the year.


The daily average combined storage of lakes Buchanan and Travis on July 1, 2016, was greater than 1.95 million acre-feet.  In accordance with the 2015 Water Management Plan, environmental flow requirements for freshwater inflows to Matagorda Bay are set to the OP-4 category from July 2016 through February of 2017.  The actual bay inflows for the period July 1 to August 31 of 367,928 acre-feet exceeded the three-month Fall freshet total of 307,800 acre-feet.  As a result, the two-month bay inflow criteria for the periods ending in September and October is the “intervening” criteria under OP-4 of 133,000 acre-feet.  Earlier in 2016, actual bay inflows for the period March 1 to April 30 of 870,255 acre-feet exceeded the three-month Spring freshet total of 246,200 acre-feet criteria under OP-3.  As a result, the two-month bay inflow criteria for the periods ending in May and June was the “intervening” criteria under OP-3 of 76,000 acre-feet.


LCRA’s obligation to release water from lakes Buchanan and Travis to meet freshwater inflow needs is subject to the availability of inflows to lakes Buchanan and Travis in excess of senior water rights. 
 
See Chapter 4 of the 2015 Water Management Plan for a more complete description of the freshwater inflow criteria for Matagorda Bay.
*Freshwater inflows to Matagorda Bay are calculated using flow at the U.S. Geological Survey's (USGS) Bay City gauge minus the water diverted from the river downstream of the Bay City gauge. However, the Bay City gauge is strongly affected by tides from the Gulf of Mexico and readings may be inaccurate when flow at Bay City is low, below about 2,300 cfs. At low flows, LCRA estimates the flow at Bay City based on flow at LCRA’s Lane City gauge minus water diverted downstream of Lane City. The Lane City gauge is upstream of the Bay City gauge and is not influenced by tide.




Long-Range Lake Level and Storage Forecasts (Links) Historical Data and Reports (Links) Useful Links
Weather forecasts for the LCRA service area LCRA Hydromet System Recreation and Water Quality

© 1996- Lower Colorado River Authority. All rights reserved.