Thursday, December 15, 2011

December Aquifer Update

Drought Status: Critical Stage III
Barton Springs: 18 cfs (19.5 cfs 10-day average)
Lovelady: 194.0 ft

The recent rainfall totals for November were near average, and above-average for December. That has brought about some relief to the dryness, but very nominal recharge and relief to the aquifer. Barton Springs discharge has temporarily spiked in response to the rainfall, but minimal response in the Lovelady well indicates very little addition to storage.

A great summary of the recent rains can be found on Bob Rose's (LCRA) blog. Click here.

The District's December newsletter highlights the current drought.

The Office of the Texas State Climatologist (OTSC) has a good statewide summary of the 2011 drought--click here.

Monday, December 5, 2011

November-December Rains Help, but....

Recent rainfall totals of up to 5 inches throughout central Texas since mid-November have been a welcome addition to record-breaking dry year. In fact, the rainfall for November and December total just above average for those two months. Consecutive above-average rainfall months haven't occurred since June and July of 2010 with passing of Hurricane Alex and other tropical storms.

Although these rains have set the conditions for runoff that could help alleviate the groundwater drought, the recent rains have not produced runoff and are far from ending our drought. The Blanco River (at Wimberley) and some of the more urbanized creeks in the Austin area, such as Williamson and Slaughter, had temporary rises in stage and flow due to the flow. However, Onion Creek has not had any substantial flows from these rainfalls. Barton Springs has also had a temporary rise due to the localized (urban-runoff) effects, but will quickly decline to pre-rainfall levels in the next few days.

Many months of above-average rainfall, or sufficiently large rainfall events (>10 inches) under the right conditions, are needed to help alleviate the drought conditions.

Summary of 2011 Drought by the Office of the State Climatologist

A great summary article from the Fountainhead of the 2011 drought by the State Climatologist (Nielsen-Gammon) can be found by clicking here. The Office of the State Climatologist also has an excellent summary of the 2011 drought. Click here for a link to the summary report. The figure below is from the Nielsen-Gammon article and shows just how unusually hot and dry the 2011 summer was. Note the average summer temperatures were >2 degrees hotter and about 1 inch drier than previous record-breaking summers.