PACLIM Workshop
How is the CA Water Supply Outlook Shaping Up?
March 2015
Pacific Grove, CA
By Maurice Roos
CA Dep’t of Water Resources
CA 2012 LEVEL WATER SUPPLY AND USE (Million Acre-Feet)
79.6
Colorado River 4.4
Ground Water Overdraft 1.5
Land Use Changes 1.5
Inflow from Oregon 1.4
Depletion
35.0
79.6
Urban
7.2
Agriculture
25.6
Possible Development 3.0
Natural
Runoff
70.8
Managed Wetlands 1.0
Development Improbable 6.0
Other North Coast
7.5
Remaining
in Streams
44.6
In-stream Fishery 2.1
North Coast
Wild and
Scenic Rivers
17.8
Req'd Delta Outflow
7.0
Water Supply
Evaporation 1.2
Water Use
Outflow to Nevada 1.2
California Net Water Supply in Water Year 2000
Local Surface
32
29
Ground Water
Environmental
In-stream
12
1
Recycled
SWP
12
6
8
Colorado River
CVP and Other Federal
Northern Sierra Precipitation
2012-13
2013-14
2014-15
Monthly Average
20
18
Precipitation in Inches
16
14
12
10
8.4
9.0
8
8.0
6.9
6.3
6
4
3.0
3.6
2.1
2
1.0
0
October
November Decemeber January
February
March
April
May
June
2015 Water Year
Mid-Sierra Snowpack Buildup
April 1 Snow-Water Content
13 Northern Sierra Nevada Snow Courses
70
60
50
inches
40
30
20
10
0
y = -0.070x + 30.855
R² = 0.012
April 1 Snow Water Content
12 Northern Sierra Snow Courses
(Original 13 less Lake Spaulding)
70
60
inches
50
40
30
20
10
0
y = -0.0613x + 31.15
R² = 0.0091
April 1 Snow-Water Content
13 Southern Sierra Nevada Snow Courses
70
60
50
inches
40
30
20
10
0
y = 0.0268x + 26.212
R² = 0.0013
Sacramento River (SBB+FTO+YRS+AMF Combined)
April - July Runoff in percent of Water Year Runoff
70%
70%
Linear regression (least suqares) line showing historical trend
65%
60%
60%
3-year running average
55%
y = -0.0008x + 0.4312
R² = 0.0938
Percent of Water Year Runoff
50%
50%
45%
40%
40%
35%
30%
30%
25%
20%
20%
15%
10%
10%
5%
0%
0%
1906
1916
1926
1936
1946
1956
1966
1976
Water Year (October 1 - September 30)
1986
1996
2006
Water Year
2014
2012
2010
2008
Dry
2006
2004
Below Normal
2002
2000
1998
1996
1994
Above Normal
1992
1990
1988
1986
1984
Wet
1982
1980
1978
1976
1974
1972
1970
Unimpaired Runoff (maf)
Sacramento River Unimpaired Runoff Since 1970
Critical
40
35
30
25
20
15
10
10
90
5
0
Storage in 154 Major In-State Reservoirs on March 1
Amount in MAF
40
Capacity = 38.0 MAF
35
29.2
30
27.5
Average = 24.9 MAF
25.9
25
21.6
20
25.1
21.9
18.2
16.2
16
15
12.9
17.7
12
10
5
0
1977
1983
1991
1992
2008
2009
2010
2011
2012
2013
2014
2015
120
SWP Water Allocations
100
Percent
80
60
40
*
20
0
* Preliminary
Year
COMPARISON WITH PREVIOUS DROUGHTS
Average Annual Drought Period Runoff in Million Acre-Feet
20
18.6
15
12.0
10
8.7*
13.1
11.2
12.4
10.0
9.8
11.2
10.4
6.7
5
0
WY
Average
1578-1580 1918-1920 1924-1926 1929-1934 1947-1950 1959-1961 1976-1977 1987-1992 2007-2009 2012-2014
SACRAMENTO FOUR RIVER RUNOFF
* From tree rings
COMPARISON WITH PREVIOUS DROUGHTS
Average Annual Drought Period Runoff in Million Acre-Feet
6
6.0
4.3
4
3.5
2.3*
2
4.0
3.7
3.3
2.7
2.7
2.5
1.5
0
WY
Average
1653-1655 1918-1920 1924-1926 1929-1934 1947-1950 1959-1961 1976-1977 1987-1992 2007-2009 2012-2014
SAN JOAQUIN FOUR RIVER RUNOFF
* From tree rings
1920
1923
1926
1929
1932
1935
1938
1941
1944
1947
1950
1953
1956
1959
1962
1965
1968
1971
1974
1977
1980
1983
1986
1989
1992
1995
1998
2001
2004
2007
2010
2013
Monthly Precipitation (mm)
Northern Sierra 8-Station Precipitation for January
from 1920-2015
900
800
700
600
500
400
y = 0.1122x + 210.84
R² = 0.0005
300
200
100
50
0
Year
Global SST Departures (°C) During the Last
Four Weeks
From CPC, NOAA
Ararat Cloud Cap