Wednesday, July 29, 2009

Critical Stage Continues, Emergency Response Period approaches

Drought Stage: Critical
Barton Springs flow: 15 cfs (16 cfs 10-day average)
Lovelady Well: 196.6 feet (depth to water)

The District Board may declare an Emergency Response Period (ERP) during extreme drought conditions, when a 10-day running average rate of discharge from Barton Springs is equal to, or less than, 14 cfs. The ERP is the next, and last, drought declaration our current rules allow. What measures are implemented is to be determined by the Board. Note that rule revisions are currently being considered by the Board that would add another drought stage called "Exceptional" at the 14 cfs threshold (increase reductions to 40%), and then move the ERP to a 10 cfs threshold. However, those rules may not be in place until September.

Thursday, July 23, 2009

Severity of drought approaching 1950s

Last night (July 22) we received about 1.3 inches of rain! It was the first trace of rain we've seen in 22 days at the Manchaca (South Austin) rain gauge at the Conservation District office. In addition, 21 of the last 30 days at or above 100 degrees! Apparently, that's the hottest July EVER. Although the rain was welcome, we're very much still in a critical drought, and much more is needed. In fact, we are about 7 inches behind for the year.

“What makes our current drought unique is not the duration but the severity,” LCRA meteorologist Bob Rose said. See quote and Austin-American Statesman article by clicking here.

Although Barton Springs has jumped up to 19 cfs after the rains, the amount was insufficient to provide significant recharge. Unless we recieve more rain, springflow will recede over the next few days to pre-rain conditions.

Drought Stage: Critical (approaching Emergency Response Period)
Barton Springs (July 22): 19 cfs (expected to drop below 16 cfs over the next few days without rain), 15.6 cfs 10-day average
Lovelady Well: 196.5 ft

Fire bans have been in place for both Hays and Travis Counties for many months. Click here for a link to an Austin-American Statesman article.

Other impacts include >3.6 billion in Texas agricultural losses to date, which could eclipse the 2006 losses by the year's end. Click here for the story.

Is this drought as bad as it has been historically...that depends how far back you go. Click here to read about "mega droughts" in the 1600's.

Thursday, July 16, 2009

2008-9 Drought Summary and Impacts

The BSEACD is not alone in its Critical Stage drought declaration. The Edwards Aquifer Authority in San Antonio and the Hays-Trinity Groundwater Conservation District have similarly issued Critical Stage declarations. Indeed, the drought is reaching historic proportions. Currently every county in Texas is reporting at least 1 impact from the drought. However, Hays and Travis counties report the most impacts of the state (source: drought impact reporter, link). Below is a quick summary of the drought in central Texas and some of its impacts.

Rainfall (or lack of it!)
  • 7 inch deficit to date for 2009;
  • 16 inch deficit from 2008 (~half of normal); 4th driest year since 1856, driest year since 1956.
That makes for one of the driest year and half periods we've had since we've keeping records in the late 1800's. 2008 was the driest year experienced since the 1950s. It is no surprise then that meteorologically this drought ranks as "Exceptional" according to the US Drought Monitor. The current drought is, according to State Climatologist, the most severe since the 1917-18 drought.

Surface Water
Lack of rain means no runoff, so streams and lakes are suffering.
  • Lake Travis is currently at 50% capacity; yearly inflows are likely to be the lowest ever recorded since it was built in the early 1940s.
  • USGS stream gauges that have readings are reaching their all-time low or are below their 10th percentile.

Water Levels
The lack of rain also translates into less recharge of the groundwater resources and therefore water levels and springs are reaching historic lows:
  • The Lovelady drought index well has reached depths equivalent to the 1950s drought--the worst in recorded history for our area;
  • Older, shallower wells in the Edwards Aquifer are going dry; many pumps within wells are being lowered;
  • The Trinity Aquifer has probably been hit the hardest to date, with many wells reported to have problems just west of the BSEACD in the Hays Trinity Groundwater Conservation District.
The lack of rainfall translates into less recharge, which results in declining water levels and ultimately declining springflow.
  • Barton Springs is at about 16-17 cfs (average is 69 cfs for this time of year), and has only been lower once in 30 years;
  • San Marcos Springs is flowing at 88 cfs (average is 191 for this time of year);
  • Jacob's Well (Trinity Aquifer spring in Wimbereley) has stopped flowing;
  • Anecdotal evidence from Hill Country residents indicate many smaller springs have stopped flowing.

Drought Outlook
The outlook over the next few months, save for any tropical system that moves into our area, is also grim. The image below is from drought outlook which shows our area for "drought to persist."

However, there is reason to be hopeful that the Fall will be wetter than normal. The national Oceanic and Atmospheric Administration indicates that we are moving into a "La Nina" system in the south Pacific, which generally indicates wetter conditions for much of Texas. Click here to find out more. Let's hope that happens!

Thursday, July 9, 2009

Barton Springs and water levels continue to decline

Current Conditions: Critical Stage
Barton Springs: 18.4 cfs (10-day average due to local showers early in July); daily value 16 cfs
Lovelady Well: 196.30 ft

Water levels are approaching historic lows and impacting well users. The District has documented several wells that have essentially gone dry or had to have their pump lowered. These are wells that produced water during other historic drought periods, yet are now having yield problems. This highlights the severity of this drought and the increasing demands placed on groundwater resources.


Monday, July 6, 2009

LCRA Meteorologist Bob Rose's summer outlook

Bob Rose provides an outlook for this summer:

"With El Niño strengthening over the next few months, the atmosphere should eventually respond, bringing more frequent periods of rain and thunderstorms, beginning sometime in the late summer or fall. Until then, I expect near normal to slightly below normal rainfall across Central Texas this summer. Overall, I don’t expect the same dry pattern we saw last summer, but I also don’t expect a clear end to the drought. Historically, summer periods of transition between La Niña and El Niño have produced patterns of near normal rainfall. Summer’s temperature will average warmer than normal..."

Click here to link to Bob's blog.

Wednesday, July 1, 2009

Blanco River flow approaching drought of record conditions

Flow in the Blanco River at Wimberley is approaching low levels not seen since the 1950s. Currently the river is flowing ~5 cfs (the lowest recorded is ~2 cfs in 1956).

The picture shows that only a trickle remains of the river as it enters the recharge zone of the Edwards Aquifer. Residents tell us that this portion of the river normally flows higher than this during drought periods, and is as bad as it was in the 1950s.

The exceptional drought conditions combined with increasing pumping from the Trinity aquifer in the Hill Country have produced these low flow conditions. Baseflow in the Blanco River is derived from springs and seeps that issue from the Trinity Aquifer. As those springs and seeps diminish, so does the river flow. In addition, the Blanco River is a source of recharge for the Edwards Aquifer. With less flow entering the recharge zone of the Edwards Aquifer, less recharge occurs.