Indicator Relationships for Regression CalculationsPresented by David Hoekema

Surface Water Methodology Technical Working Group

Date: February 19, 2015

Settlement Document Subject to I.R.E. 408

How well to Box Canyon Springs and Spring Creek represent water supply conditions for the TFCC?

Settlement Document Subject to I.R.E. 408

1912

1915

1918

1921

1924

1927

1930

1933

1936

1939

1942

1945

1948

1951

1954

1957

1960

1963

1966

1969

1972

1975

1978

1981

1984

1987

1990

1993

1996

1999

2002

2005

2008

2011

0

2,000,000

4,000,000

6,000,000

8,000,000

10,000,000

12,000,000

14,000,000

16,000,000

18,000,000

20,000,000

Cumulative Change in Volume of Water Stored Within ESPA

Water Budget Volume Change Annual

Cu

mu

lati

ve S

tora

ge

Ch

ang

e (a

cre-

feet

)

1952 – 2013 ≈ 11,230,000 AF total removed from storage1952 – 2013 ≈ 184,000 AF/yr average removed from storage

Settlement Document Subject to I.R.E. 408

1951

1953

1955

1957

1959

1961

1963

1965

1967

1969

1971

1973

1975

1977

1979

1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

2003

2005

2007

2009

2011

2013

0

2,000,000

4,000,000

6,000,000

8,000,000

10,000,000

12,000,000

14,000,000

16,000,000

18,000,000

20,000,000

250

270

290

310

330

350

370

390

410

430

Box Canyon and Aquifer Storage ChangeComparison (1951-2013) r² = 0.91

Cumulative Change in Aquifer Storage Box Canyon Average Annual Discharge

Cu

mu

lati

ve A

qu

ifer

Vo

lum

e C

han

ge

[ac-

ft]

Ave

rag

e D

isch

arg

e B

ox

Can

yon

[cf

s]

Box Canyon Correlates Well to Change in ESPA Storage

Settlement Document Subject to I.R.E. 408

Spring Creek Correlates Well Reach Gains

1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 20130

500

1000

1500

2000

2500

3000

3500

4000

4500

0

50

100

150

200

250

300

350

400

450

Spring Creek and Reach Gains (r² = 0.713)

Reach Gain Spring Creek

Rea

ch G

ain

s [c

fs]

Sp

rin

g C

reek

[cf

s]

Spring Creek Correlates better with ESPA Storage Change for 1991-2014 Period

Settlement Document Subject to I.R.E. 408

r = 0.77

Settlement Document Subject to I.R.E. 408

Jan-

11

Mar

-11

May

-11

Jul-1

1

Sep-1

1

Nov-1

1

Jan-

12

Mar

-12

May

-12

Jul-1

2

Sep-1

2

Nov-1

2

Jan-

13

Mar

-13

May

-13

Jul-1

3

Sep-1

3

Nov-1

3

Jan-

14

Mar

-14

May

-14

Jul-1

4

Sep-1

40

50

100

150

200

250

300

350

4305

4307

4309

4311

4313

4315

4317

4319

Monthly Average Spring Flow and Groundwater Depth

Spring Creek Wells

Sp

rin

g C

reek

Flo

w [

cfs]

Gro

un

dw

ater

Ele

vati

on

[ft

]

Settlement Document Subject to I.R.E. 408