Cloudy skies, showers and thunderstorms are likely today over the Colorado River basin ending later this afternoon over western and central regions but continuing this evening in coastal areas.  High temperatures will be in 60s in coastal areas, 50s elsewhere with overnight lows falling to the upper 20s west and 30s elsewhere.  The water temperature at the surface of Lake Travis this morning was about 54 degrees.

Flows into lakes Inks, LBJ, and Marble Falls are being passed through Wirtz and Starcke dams to Lake Travis.  Lakes Buchanan and Travis are forecast to rise slowly over the next several days. Inflows to Lake Buchanan are being held in Lake Buchanan. Lake Travis will rise a little faster as inflows from the Pedernales River and pass-through flows from the lakes above Lake Travis flow in. See the sections below for the latest updated information on lake level forecasts.

As of 6:30 a.m. today, the level of Lake Buchanan is at 1,003.34 feet above mean sea level (ft msl), which is about 8.8 feet below its historic February average of 1,012.12 ft msl.  The level of Lake Travis is currently at 670.65 ft msl, which is at the historic February average of 670.67 ft msl.  The total combined storage in the Highland Lakes two water storage reservoirs, lakes Buchanan and Travis, is about 1,495,000 acre-feet, or 74 percent of capacity.

Unscheduled releases could occur at any of the Highland Lakes dams without notice to maintain lake levels, pass flood flows, meet sudden demands for hydroelectric power, or for testing and maintenance of equipment.  In the event of high energy demands in Texas, the Electric Reliability Council of Texas (ERCOT) may call upon LCRA for hydroelectric generation at anytime without notice.  Lakeside residents and lake users immediately downstream of the dams should take necessary precautions against possible high flows and higher lake levels.

The Highland Lakes provide water for irrigation, municipal, industrial and environmental needs around the Highland Lakes and along the lower river from Tom Miller Dam to Matagorda Bay.  Significant rainfall is needed to replenish the water consumed from the lakes, the water released for downstream needs, and the water lost to evaporation. To see graphs of historical lake and storage levels go to: http://www.lcra.org/library/media/public/docs/water/drought/Historical_Lake_levels.pdf

In the Colorado River below the Highland Lakes, streamflow remains elevated from rainfall earlier this week.  Streamflow in the lower basin is ranging from about 1,200 cfs at Bastrop to 3,700 cfs at Columbus. Further dowstream from Wharton to Bay City streamflow is ranging from 6,500 to 7,600 cfs.  To see real-time hydrologic data please go to: http://hydromet.lcra.org/.

Elevations contained in this summary are based on LCRA "legacy" or NGVD 29 datum and are not adjusted to the newer NAVD 88 datum.  FEMA and the National Flood Insurance Program reference the NAVD 88 datum in their floodplain maps and regulations.  Lake levels reported by LCRA should not be used to determine first floor elevation of buildings for compliance with floodplain regulations.  Surveyors should refer to http://harn.lcra.org/ for information about LCRA GPS control marks and benchmarks.

2010 Water Management Plan: On January 27, 2010, the Texas Commission on Environmental Quality approved an amended Water Management Plan for the operation of the Highland Lakes.  This new Water Management Plan contains amended requirements to provide water for river habitat and water quality along the lower river ("Instream Flow Requirements") and for the health and productivity of Matagorda Bay ("Bay and Estuary Requirements"). These requirements vary between lower "critical" and higher "target" amounts according to the amount of water stored in the Highland Lakes at different times of year, and from month to month according to seasonal environmental needs.  The lower river and Matagorda Bay may receive more water than required by the Water Management Plan because of downstream conditions.

Instream Flow Requirements: The minimum or "critical" instream flow requirements are to maintain at least 46 cfs at the Austin river gauge and at least 120 cfs at the Bastrop river gauge at all times.  In addition, at least 500 cfs are to be maintained at the Bastrop river gauge for a continuous six-week period in March, April and May.  On February 1, 2010, the combined storage of lakes Buchanan and Travis was 1,335,000 acre-feet.  Since the combined storage was less than 1.4 million acre-feet, interruptible water supply for agriculture is currently under curtailment and "critical" instream flow requirements apply to flows at Bastrop, Columbus and Wharton.

Bay and Estuary Requirements: On February 1, 2010, the combined storage of lakes Buchanan and Travis was 1,335,000 acre-feet.  Since the combined storage of lakes Buchanan and Travis was less than 1.7 million acre-feet and greater than 1.1 million acre-feet, LCRA is required to release storable inflows up to but not exceeding 150% of critical freshwater inflow needs each month in 2010.  The critical Bay and Estuary requirement is 14,260 acre-feet, so the required release will be at least 21,390 acre-feet (when inflows to the Highland Lakes are sufficient to supply these flows).