Wednesday, January 23, 2013

Drought Conditions Continue

Drought Status: Alarm Stage II
Barton Springs: 29 cfs (10-day average)
Lovelady: 466.6 ft-msl

Drought conditions continue in early 2013 and, unfortunately, the forecast is for hotter and drier conditions than normal. If these dry conditions continue, data from Barton Springs indicates we could enter into Stage III Critical Drought as early as mid- to late-February. Data from our other drought trigger, the Lovelady Well, suggests we'll enter into Stage III by early March. It only takes one of our triggers to cross its respective drought threshold for the Board to make a drought declaration.

Data for Barton Springs may be a little bit elevated above the actual discharge values as suggested by some recent manual measurements and the level in the Lovelady well. We will continue to collect more information and possibly revise our estimates. Below are charts estimating the entry into Stage III by using recession data from the 2011 drought.

Drought Prediction Chart

Wednesday, January 9, 2013

Need More Rain to Improve Drought Status

Drought Status: Stage II Alarm
Barton Springs: 28.6 cfs (10 average)
Lovelady well: 468 ft-msl

The precipitation received this week is a welcome respite from the overall dry conditions that have prevailed in the area this winter. The District's rain gauge reads about 2.5 inches received over the past 48 hours (Jan. 8 and 9). However, the rains have not been substantial enough to generate any considerable amount of runoff in the creeks over the contributing or recharge zones of the Edwards Aquifer. Most of the water went to replenishing soil moisture.  Despite not generating runoff, the recent rains have primed soil moisture conditions for generating recharge to the aquifer in the event of more precipitation in the next few weeks.

According to the National Weather Service the outlook for more precipitation in central Texas in January and February is not promising, having predicted drought conditions to "persist or intensify". If dry conditions persist, it is likely that the aquifer will enter Critical Stage III drought in March. 

Tuesday, January 8, 2013

2012 warmest and second most extreme year on record for contiguous U.S.

Above is a link to the 2012 State of the Climate by the National Climate Data Center.

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.