Transcript Document

Aquifer Storage and Recovery
10-year Rolling Average
• The Aquifer Storage and Recovery (ASR) Program utilizes the SAWS ASR
facility for storage and delivery of Aquifer water leased by the EAA.
• The leases and options, to total 50,000 acre-feet per year, are used to
protect springflows during identified drought-of-record conditions.
• When triggers are reached SAWS will use water stored in the ASR facility
to serve as a base load supply in its service area nearest to the springs
July 16, 2015
Locations / Examples
Distribution link to Twin Oaks ASR Facilities
SAWS Primary Pump
Stations supporting Twin
Oaks ASR operations
Not to scale
Edwards Aquifer
Public Water Supply
Wells
Randolph
Flow Meter
Seale Flow
Meter #2
Seale Flow
Meter #1
Artesia Pump
Station
Seale Pump
Station
42” Steel Pipe;
1 mile
Edwards Aquifer
Public Water Supply
Wells
Randolph
Pump Station
42” Steel Pipe;
7 miles
(Connections to Distribution)
Artesia Flow Meter
Edwards Aquifer
Public Water Supply
Wells
The Twin Oaks ASR Facilities
42” Steel Pipe;
3 miles
70 MGD
pumps
Treatment &
clearwells
Storage
and Recovery
Wellfield
(29 wells)
Not to scale
Page 3
Implementing Forbearance & 2013 ASR Summary
ASR Triggers
EAHCP § 5.5.1 - index well J-17’s monthly average falls
below 630 feet below mean sea level (msl) within an
identified repeat of drought conditions, indicated by a
ten-year rolling average recharge of the Edwards Aquifer
is below 500,000 acre-feet, then pumping of selected
wells on the northeast side of SAWS water distribution
system will be reduced in an amount that equals the
amount of water returned from the ASR.
Total Estimated Recharge 1934 – 2013
Edwards Aquifer
3000
2500
Thousands of Acre-Feet
2000
1500
1000
500
0
1934
1939
1944
1949
1954
1959
1964
Total Estimated Recharge
1969
1974
Average
1979
Min
1984
Max
1989
DOR
1994
1999
2004
2009
• Historical Triggering of ASR
• 1946-1959 10 year AVG < 500k
• 1954-1957 J17 < 630
Year
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
10 Year AVG
486,760
488,950
463,560
474,420
463,560
392,480
364,250
353,700
313,820
280,240
229,000
301,000
454,290
472,520
J17 Annual Low
663.6
665.8
653.7
655.6
653.8
640.6
633.4
630.5
628.9
624.2
612.5
624.4
653.3
661.5
• Historical Triggering of ASR if 5yr AVG
• 1946-1957, 1964-1967, 2012-2013
5 year AVG < 500k
• 1954-1957 and 1967
J17 < 630
Year
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1964
1965
1966
1967
2012
2013
5 Year AVG
495.14
468.1
449.14
438.58
373.06
289.82
260.4
258.2
189.1
187.42
168.18
341.6
473.04
432.78
412.4
457.82
332.58
326.54
J17 Annual Low
663.6
665.8
653.7
655.6
653.8
640.6
633.4
630.5
628.9
624.2
612.5
624.4
632.8
645.6
642.7
624.9
637.6
631
• As of 2013
Year
Edwards Aquifer Annual Recharge
Recharge (acre-feet)
2004
2,176,100
2005
764,000
2006
201,600
2007
2,162,300
2008
212,900
2009
211,000
2010
813,500
2011
112,000
2012
313,500
2013
182,700
10 year AVG
714,960
• Projected 2014
• < 26,400 ACFT to trigger
Year
Edwards Aquifer Annual Recharge
Recharge (acre-feet)
2005
764,000
2006
201,600
2007
2,162,300
2008
212,900
2009
211,000
2010
813,500
2011
112,000
2012
313,500
2013
182,700
2014
26,400
10 year AVG
499,990
• Projected 2014-2015
• To Trigger
• < 790,000 ACFT total
• < 395,000 Annually
Year
Edwards Aquifer Annual Recharge
Recharge (acre-feet)
2006
201,600
2007
2,162,300
2008
212,900
2009
211,000
2010
813,500
2011
112,000
2012
313,500
2013
182,700
2014
395,000
2015
395,000
10 year AVG
499,950
• Projected 2014-2016
• To Trigger
• < 991,500 ACFT total
• < 330,500 Annually
Year
Edwards Aquifer Annual Recharge
Recharge (acre-feet)
2007
2,162,300
2008
212,900
2009
211,000
2010
813,500
2011
112,000
2012
313,500
2013
182,700
2014
330,500
2015
330,500
2016
330,500
10 year AVG
499,940
• Projected 2014-2017
• To Trigger
• < 3,150,000 ACFT total
• < 787,500 Annually
Year
Edwards Aquifer Annual Recharge
Recharge (acre-feet)
2008
212,900
2009
211,000
2010
813,500
2011
112,000
2012
313,500
2013
182,700
2014
787,500
2015
787,500
2016
787,500
2017
787,500
10 year AVG
499,560