Friday, January 4, 2013

2012 Year in Review

Barton Springs: 29 cfs
Lovelady: 468.2 ft-msl

Over the past year the aquifer has experienced multiple drought stages. The aquifer started 2012 in Critical Stage III drought, brought about by the most severe single-year drought in Texas history. Above average rainfall in the winter and early spring months of 2011-2012 generated sufficient soil moisture, runoff, and sustained creek flow to recharge the aquifer enough for the District’s board to downgrade the Critical Stage III drought to Alarm Stage II in February and “No Drought” conditions in March. Above average rainfall conditions persisted until about mid-April allowing Barton Springs to reach a peak discharge above 100 cfs. After the above-average wet conditions at the start of the year, precipitation in May was not substantial enough to maintain recharge conditions at former rates. Flow in creeks began to subside, diminishing the amount of recharge entering the aquifer. The summer months in 2012 were very dry causing creeks to eventually stop flowing over the recharge zone and aquifer levels to continue to decrease. By late August, flow in Barton Springs had reached 69.3 cfs. Precipitation in September was scarce and a steady decrease of aquifer levels continued. Meager rainfall in October was not sufficient enough to overcome the soil moisture deficit incurred during the summer and therefore unable to generate runoff or creek flow to recharge the aquifer. Dry conditions persisted in November; the Board declared Alarm Stage II Drought on November 15 after both official drought indicators at Barton Springs and Lovelady monitor well passed their drought thresholds of 38 cfs and 478.4 ft-msl respectively. That alarm stage remains in effect as of January 4, 2013. The total rainfall recorded at the district for 2012 of about 35 inches was above the yearly average for the area (33.38 inches). Despite the above-average rainfall, it is likely the exceptional recharge deficit incurred during the 2011 drought has prevented the aquifer from maintaining non-drought levels.

The U.S. Seasonal Drought Outlook by the National Weather Service indicates that drought conditions are expected to “persist or intensify” for central Texas through January and February of 2013. According to previous recession curves for Lovelady monitor well, if precipitation conditions remain scarce the drought threshold for a Critical Stage III drought will likely be passed in early March 2013. 

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