Thursday, April 17, 2014

Recent Rains not enough to end Declining Trend; Groundwater Drought Near

No-Drought
Barton Springs discharge: 47 cfs (10-day average)
Lovelady Monitor Well: 478.89 ft-msl

The weather this week brought with it strong gusts of winds, hail, and in some places more than an inch of rain over the course of a few minutes. Despite the dramatic downpour, runoff and flow in creeks over the recharge zone of the aquifer did not amount to much. Water level in the Lovelady monitor well was not noticeably influenced, see figure below. At the time of this post, Lovelady monitor well is about 0.5 feet above its Stage II Drought threshold. Over the past month or so, water level in the well has been decreasing on average 0.2 feet per day. It is likely the District's board will make a drought declaration at their next meeting, which is scheduled for next Thursday, April 24.  Barton Springs is flowing at 47 cfs and may not cross its drought threshold of 38 cfs until mid May. 
Currently, the US Drought Monitor rates much of central Texas as undergoing Abnormally Dry to Extreme Drought conditions. NOAA's Climate Prediction Center (CPC) expects drought in much of the western 2/3 of Texas to intensify during the Spring of 2014 due to prevailing El Niño-Neutral conditions. Despite the grim prediction for the remainder of Spring, the CPC place better than 50% odds that El Niño conditions will develop by this summer. El Niño, generally, means wetter than normal conditions for Texas.



Monday, April 7, 2014

Small Weekend Rain, No Runoff

No-Drought
Barton Springs discharge: 48 cfs 10-day average
Lovelad Monitor well: 480.8 ft-msl

The rain gauge at the District office collected 0.21 inches from the rain that came through the area this weekend. Campy Mabry had a similar total rainfall of 0.20 inches. Before the rain this weekend, the District rain gauge had not received rain since mid-March. At the time of this post, the hydrographs for Lovelady monitor well and Barton Springs do not seem to have been significantly influenced by this weekend's rain. It appears that we are still on track to reach Lovelady well's Stage II Alarm Drought threshold by the end of April unless substantial precipitation occurs.

Wednesday, April 2, 2014

Groundwater Drought Looming Near

No-Drought Conditions
Barton Springs Flow: 49 cfs (10-day average)
Lovelady Well: 481.73 ft-msl

Water level in Lovelady monitor well is just over 3 feet above its Stage II Alarm drought threshold. Unless meaningful recharge to the aquifer occurs, that threshold could be crossed near the end of April. Barton Springs flow is expected to cross its drought threshold some time after Lovelady, possibly mid-May. It only takes one of these sites to cross its respective drought threshold for the District to make a drought declaration. Despite seeing an improvement in precipitation from the months preceding it, rainfall of 1.6 inches in March was short of its 2.2 inch historic average. The District rain gauge received 1/100 of an inch in the last two weeks of March. At the time of this posting, thunderstorms are in the forecast for today and tomorrow. Given the dry conditions, rain that falls now may not be enough to slow the descent into drought, but would prime soil moisture conditions for subsequent rains to generate surface runoff and flow in the creeks, where the majority of recharge to the aquifer occurs.
The National Oceanic and Atmospheric Administration predicts that drought will persist or intensify in most of the western half of the state, while some chance of improvement exists for the eastern half. Click here to go to their website.

Monday, March 24, 2014

Drought Conditions Possible by Late April

No-Drought
Barton Springs discharge: 52 cfs 10-day avg.
Lovelady monitor well: 483.3 ft-msl

Water levels in the aquifer and flow at Barton Springs continue to gradually decline, after having reached their respective peaks in January and November, following the large storms in October of last year. According to the district rain gauge, March has received a total of 1.5 inches of rain so far, putting it on track to possibly reach its historic average of 2.2 inches. Despite the decent rainfall conditions we've seen this month, the preceding 3 months saw about 1/5 of their historic rainfall, leading to overall dry conditions and meager flow in streams where most of the recharge to the aquifer occurs. At the current rate of decline, without significant recharge to the aquifer, it is possible that Stage II Alarm Drought could be reached by late April based on water level in the District's Lovelady monitor well (see figure). Flow at Barton Springs will likely not reach its Stage II Alarm Drought threshold until later this Spring, perhaps mid-May. It only takes one, of the District's drought trigger sites to cross their respective threshold for a drought declaration to be made. The National Weather Service's Drought Outlook makes a range of predictions for parts of central Texas ranging from intensification of drought to slight improvement, depending on the county. The National Oceanic and Atmospheric Administration reports that the current ENSO cycle is currently in El Niño-Neutral, with some possibility of El Niño conditions arising in the summer or fall 2014. El Niño generally means wetter conditions for Texas. 


Tuesday, March 4, 2014

January and February see below Average Rain

No Drought
Lovelady monitor well: 487 ft-msl 
Barton Springs: 56 cfs (10-day average)

The "thunder-sleet" the Austin-area received last night may have slowed morning commutes, but brought a good start to the month of March with regards to precipitation. The rain gauge at the District office has recorded 0.69 inches so far since the start of the month, while the total historic average for March is 2.2 inches. The previous two months saw precipitation well below their respective historic averages. In January the total rainfall at the District office was 0.43 inches compared its historic average of 2.0 inches, while in February 0.44 inches fell compared to 2.4 inches historic average. Area creeks, where most of the recharge to the Barton Springs Segment of the Edwards Aquifer occurs, have scarcely flowed in 2014 due to predominantly dry conditions. As a result, water levels in the aquifer and flow rate of Barton Springs have been steadily declining. The recent rains were likely not large enough in magnitude to reverse the trend of heading towards drought. It is still too early to give an accurate prediction of when the District may surpass its drought thresholds if dry conditions persist, however it could occur sometime in the Spring. Below see a hydrograph of Lovelady monitor well, one of the District's drought triggers, since the end of 2012 through the present (click to enlarge). The graph shows the District's drought thresholds. Notice the end of the last drought cycle in the fall of 2013 and the peak of aquifer water levels in January of this year. The US Seasonal Drought Outlook predicts meteorological drought in much of the state to persist or intensify. 


Thursday, February 6, 2014

Groundwater Rise Has Ended

No Drought
Barton Springs: 68 cfs 10-day average
Lovelady: 491.04 ft-msl

For the first time since September, water level in the District's Lovelady monitor well is exhibiting a falling trend. The large storms in October provided a sudden and large amount of recharge to the aquifer that dramatically increased the rate of water level which started in September. Just in the last few weeks the rate of rise had begun to flatten out, and finally has reversed altogether. Winter 2013-2014 has seen below average rainfall. Consequently, most creeks over the Edwards aquifer recharge zone have been largely dry and not providing significant recharge.

Thursday, January 30, 2014

Sleet has no Effect on Drought Trigger Sites

No Drought
Barton Springs: 69 cfs (10-day average)
Lovelady monitor well: 491.88

Despite the disruptions it caused in the area, the freezing rain we received this week only amounted to less than 1/10 of an inch according to the District weather station, bringing January's total precipitation to 0.4 inches, well short of the historic monthly average of 2.00 inches. It appears that Lovelady water level may have reached it's peak in the last week after having been on the rise since September of last year and could now be descending, however it is still too early to say for certain.

Below see a hydrograph of Lovelady spanning from the previous peak in water level in the summer of 2012, through the beginning and end of the last drought, and into current conditions.

For real-time hydrograph at Barton Springs click here.
For real-time hydrograph of Lovelady mintor well click here

Thursday, January 23, 2014

Below Average Rain Continues

No Drought
Barton Springs: 69 cfs 10-day average
Lovelady monitor well: 492.21 ft-msl

The dry conditions observed in December are continuing into the new year. As of today, 0.31 inches of rain have been collected at the District rain gauge in January, compared to the historic average of 2.0 inches for the month. Rain is predicted for today and early next week, so there is some chance for conditions to improve. Barton Springs discharge has been steadily decreasing since the big rains in October. At the current rate of decline and without any recharge, drought conditions may be reached as early as Spring.
Lovelady monitor well is reaching a peak in its hydrograph and will likely begin to exhibit a dropping trend in the coming week.
NOAA's seasonal drought outlook predicts that meteorological drought will persist or intensify in the first few months of 2014 in much of central Texas.

NOAA Seasonal Drought Outlook:
http://www.cpc.ncep.noaa.gov/products/expert_assessment/season_drought.png

Below see a hydrograph of Lovelady well through the last few drought cycles.

Thursday, January 9, 2014

Groundwater Rise Slowing

No Drought
Barton Springs: approximately 73 cfs
Lovelady monitor well: 491.6 ft-msl

2013 ended on a dry note. In December the district rain gauge received 0.71 inches of rain, compared to the historic average of 2.5 inches. Despite dry conditions, the Lovelady monitor well hydrograph continues to rise after above-average rainfall in September and the big storms in October generated prolonged recharge to the aquifer, but is starting to slow its rate of rise. The District is currently out of drought, unlike the agencies in the surrounding area. It is important to use water resources conservatively, even in times of no drought given the fickle nature of rainfall in central Texas and the unknown long-term climate trends going into the future.

Thursday, December 26, 2013

Aquifer Update

Status: No Drought
Barton Springs: 75 cfs, very slow decline
Lovelady: 489 ft-msl and rising

On December 21 we had up to about 1 inch of rainfall that helped creeks increase in flows and result in some increased recharge. Although streams are quickly declining, the rainfall has helped to sustain the creek flow and recharge that we've enjoyed since September.

Our good aquifer levels are a bit unusual for the region. Other water resources have not benefited from the wet September and October like the Barton Springs segment of the Edwards Aquifer. For example, to our south the San Antonio segment of the Edwards Aquifer is in Stage 3 drought declaration. The highland lakes are only at ~38% capacity, and so Austin and the region depending on surface water are also under drought restrictions. West of the District, in Hays County, the Hays-Trinity GCD is under Alarm drought conditions. We have to be mindful that we can join drought status like these other agencies in a matter of months if dry conditions come back to our area. Let's hope the wet trend continues into the New Year.