Thursday, January 22, 2015

Over Night Soaking has Creeks Flowing

Stage II Alarm Drought
Lovelady monitor well: 475.85 ft-msl
Barton Springs discharge: 68 cfs 10-day average

The rain that started yesterday afternoon and fell steadily through much of last night and today has generated substantial runoff and as result, all of the area creeks are flowing. The catchment areas for the creeks responsible for much of the recharge to the Barton Springs Segment of the Aquifer, that is Onion, Bear, Slaughter, Williamson, and Barton creeks, received between about 2 to 3.5 inches over the last 24 hours, and forecasts place the chance of rain tomorrow upwards of 70%. Preceding this rain event, soils already had a high moisture content, thus conditions were prime for generation of runoff. Groundwater levels, for their part, have been on the rise since November and this rain will certainly help continue that trend, possibly even bringing water levels above the drought threshold of 478.4 ft above sea level over the course of the coming days or weeks, but that remains to be seen. 

Thursday, January 15, 2015

NWS: 2014 Cooler, Wetter than Average

Stage II Alarm Drought
Lovelady monitor well: 474.4 ft-msl
Barton Springs discharge: 67 cfs 10-day average

The National Weather Service put out their climate summary for the year 2014 in central Texas based on observations at Austin's Camp Mabry. According to the summary, Camp Mabry received 1.21 inches more rain for the year than the normal 34.22 inches and experienced temperatures 0.3 degrees Fahrenheit cooler than average. The temporal and spatial distribution of precipitation events that were able to produce groundwater recharge, caused groundwater levels to vacillate up and down, while generally exhibiting a descending trend for much of the year (see figure). Since early November 2014 groundwater levels have been on the rise and it remains to be seen whether they will rise above the Stage II Alarm threshold without more recharge. 

Thursday, January 8, 2015

Groundwater Levels Continue Fluctuating

Stage II Alarm Drought
Lovelady Monitor Well: 472.99 ft-msl
Barton Springs: 55 cfs 10-day average

The timing and magnitude of the rains over the fall and winter months have led to a continuation of odd water level oscillations that have characterized the Lovelady monitor well hydrograph over the past year (see Image). Since big rains at the end of November (the District office received over 4 inches over the course of 2 days) groundwater levels have been rising but appear to be tapering off. Currently, conditions are good for the rains predicted for this weekend to generate runoff in the creeks that flow over the recharge zone. Barton Creek is the only area creek that is presently flowing at a substantial rate, but if the rain causes flow in the other creeks it may boost water levels in the aquifer. 

Thursday, December 11, 2014

Groundwater Levels Continue Vacillating

Stage II Alarm Drought
Lovelady monitor well: 471.7 elevation ft-msl
Barton Springs: 62 cfs 10-day average

The trend of rollercoaster-like rise and falls in groundwater levels this year continues as big rains in November generated enough surface runoff to cause many of the creeks over the recharge zone of the Barton Springs Segment of the Edwards aquifer to flow for a few days. Barton Creek has been flowing continuously, albeit at a decreasing rate, since November 21st and 22nd over which period some areas received upwards of 5 inches of rain (4.25 inches at District offices). As a result, both Barton Springs and Lovelady monitor well (district drought trigger sites) experienced sudden rises in their hydrographs. Currently, Barton Springs discharge has started falling after reaching a maximum 10-day average of 65cfs; Water level in Lovelady monitor well continues to rise. According to District rules, both drought triggers sites must be above their respective drought thresholds for a drought declaration to be lifted. It is unlikely that the Lovelady well water level will rise above the 478.4 ft-msl Stage II Alarm Drought threshold before peaking, but that remains to be seen. The season's cool temperatures and cloudy weather improve the odds that any rain we do get will have a better chance of generating considerable amounts of recharge. The Climate Prediction Center has increased the likelihood it places on the development of ENSO conditions for this winter to 65% and expect it to last into spring 2015.

See the District's latest official Drought Chart here:

Tuesday, November 25, 2014

Welcome Soaking over the Weekend

Stage II Critical Drought
Lovelady: 466.68 ft-msl
Barton Springs: approximately 35 cfs 10-day average

The rain over the weekend was substantial enough to create flow in area creeks where the majority of recharge to the Barton Springs Segment of the Edwards Aquifer occurs. Hopefully these rains are the precursor to the wet conditions possible with the arrival of El Niño conditions which the National Weather Service places a 58% chance of developing during winter 2014-2015 and lasting into spring 2015. Although Barton Springs experienced a sudden increase in flow due to the rain over the weekend, that increase does not indicate an increase in groundwater storage in the aquifer, rather a sudden surge of surface water travelling quickly through developed karst conduits (caves, sinkholes, etc). Lovelady monitor well hydrograph, the District's other drought trigger site, has slowed its descent into deeper stages of drought for the time being and may be indicating a subtle rise in aquifer water levels due to the rain, but whether that is the case or not remains to be seen. To see the latest official District drought status click here

Thursday, November 20, 2014

Rain in November Average

Stage II Alarm Drought
Lovelady monitor well: 468.7 ft-msl
Barton Springs: 35 cfs 10-day avg.

Total rainfall at the district office in November of 3.2 inches was just shy of the historic average for the month of 3.3 inches. This ahead of the 58% chance NOAA's Climate Prediction Center places on El Nino (ENSO) conditions developing this winter and extending in spring 2015. ENSO conditions generally correlate with wetter periods in central Texas. Currently, despite the average rain conditions recharge to the aquifer has been minimal and consequently water levels in the aquifer are declining after a summer of roller-coaster-like ups and downs (see drought chart here).

Thursday, October 23, 2014

Water Level Roller Coaster

Stage II Alarm Drought
Lovelady monitor well: 4687.7 ft-msl
Barton Springs discharge: 35 cfs 10-day average

Over the last few months both discharge at Barton Springs and water level at Lovelady monitor well, the District's to drought trigger sites, have experienced brief two rises due to the timing of precipitation events this summer that were large enough to generate recharge to the aquifer (see figure below). Currently, with fall well underway, water level in the aquifer is on the decline, while the Climate Prediction Center, expects El Niño conditions to develop in the next month or two, potentially bringing above average rainfall to central Texas.

Monday, October 13, 2014

El Niño Development Likely in Fall and Winter

Stage II Alarm Drought
Lovelady Monitor well: 469.88 ft-msl
Barton Springs: 35 cfs

In a statement released on October 9, The Climate Prediction Center reported that El Niño conditions are likely to begin in the next 1 to 2 months. Generally speaking, El Niño conditions mean more rain for central Texas. So far this month the district rain gauge has collected just over 1 inch of precipitation of the 3.3 inch historic average. The water level in the Lovelady monitor well has experienced something of a rollercoaster of ups and downs as a result of the timing and magnitude of storms this summer see image below.

Monday, September 22, 2014

Rains Help Aquifer; Don't End Drought

Stage II Alarm Drought
Barton Springs discharge 29 cfs 10-day average
Lovelady monitor well 469.91 ft-msl

Last week some parts of Austin received 6 inches of rain. Much of that precipitation fell directly over or slightly east of the recharge zone of the aquifer, and caused a small rise in groundwater levels and increased discharge at Barton Springs. As welcome as the rain was, it would have been much more beneficial to groundwater supply for more of it to have fallen further west in the watersheds of the creeks that flow over the recharge zone. Sustained flow in the creeks is the most important source of recharge to the Barton Springs segment of the Edwards Aquifer. Rain fall directly on the recharge zone is not as likely to generate the amounts of surface runoff and flow in the creeks that are so important to providing water to our segment of the Edwards Aquifer. The bump in water levels is unlikely to last more than a couple of weeks or lead to conditions that would call for lifting the current drought declaration. A huge benefit of the recent rains is that soils are now primed to generate surface runoff if we get even modest rains in the right places.

Click here to go to the District facebook page for more on last week's rain.

Thursday, August 28, 2014

Trace Amounts of Rain in August

Stage II Alarm Drought
Barton Springs flow: 32.3 cfs 10-day average
Lovelady monitor well: 472.03 ft-msl

August has turned out to be a very dry month. At the time of this post, rain gauges at the District offices, Austin-Bergstrom International Airport, and Camp Mabry received little more than trace amounts of moisture during the entire month. The historic average rainfall for August is just over 2 inches. As a result of this lack of precipitation, water levels in the aquifer continue the descending trend that lead the District Board of Directors to declare Stage II Alarm drought at their last meeting on August 14.