1 2 3 4 Santa Cruz a B D C G
Selected USGS Stream San Lorenzo River watershed Gaging Stations A. Pescadero Ck SLVWD diversion watershed B. San Lorenzo R. Waterman Switch C. Boulder Ck 40 Isohyetal (in/yr)* D. Zayante Ck Precipitation station used E. Bean Ck F. San Vicente Ck in mapping. G. San Lorenzo R. at Big Trees Selected precip. stations: 1. Lockheed 2. SLVWD Office A 3. Ben Lomond 4 B 4. Santa Cruz
1 C 2Boulder Creek
Quail Hollow D Ben 3 Lomond Olympia
E Scotts F Valley
Felton Pasa- tiempo G
P ac if ic O ce an 4 *Contours generalized for estimating 1937-96 average watershed Santa precipitation; adopted from larger map by Geomatrix, 1999. Cruz
012miles SLVWD Water Supply Master Plan NM Johnson Figure 3-1. Isohyetal Map of San Lorenzo Valley Tropical moisture entrained in jet stream.
a. Cold Cyclonic Storm b. Warm Advective Storm
Figure 3-2 Satellite Images of Typical Pacific Storms Imagery source: www.goes.noaa.gov/
SLVWD Water Supply Master Plan NM Johnson Santa Clara Valley
Figure 3-3 Radar Image Showing Influence of Ben Lomond Mountain on Rainfall Distributon
Southwest Northeast Average Annual Precipitation (in/yr)
<30" 50" 60+" 50" <45" 50+" 30" 25" 15" r
Santa Clara Valley Bonny Doon Summit South San Lorenzo Valley Castle Rock San Ben Lomond Mtn. Mt. Bielawski Los San Francisco Gatos
Coast Rive San Lorenzo Scotts Jose Bay Valley Santa Cruz Mountains Davenport SLVWD Boulder Ck Santa Cruz Watersheds Ben Lomond Felton Figure 3-4 Schematic Coast-to-South Bay Profile Illustrating Orographic Influence on Rainfall Distribution (adopted from Geomatrix, 1999; see Fig. 3-3 for approximate line of profile)
ppt-xsec4.xls Fig 6/7/2007 4:18 AM NM Johnson 25%
Ben Lomond 4, WY's 1973-2007 20% Santa Cruz, WY's 1931-2006 Lockheed, WY's 1959-2006
15% nnual Rainfall
10% Percent of Average A Average of Percent 5%
0% Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep a. Comparison of Three Rainfall Stations
25%
Average of 3 Rainfall Stations (Table 3-4) Average of 6 Gaged Streams (Table 3-9) 20%
15% nnual Rainfall and Streamflow 10%
5% Percent of Average A Average of Percent
0% Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep b. Rainfall versus Streamflow
Figure 3-5 Monthly Average Rainfall and Streamflow, Selected Stations
Ppt-SC-LH4.xls Fig-MthAvg 6/7/2007 4:00 AM NM Johnson Percent of Time Rainfall is Less Than 100% 90% 80% 70% 60% 50%40% 30% 20% 100
Max. Rainfall* 10 (inches) Date(s) 1-day 11.5 1/4/82 2-day 16.1 1/4-5/82 3-day 16.1 1/3-5/82 7-day 20.4 2/12-18/86 14-day 22.8 12/18-31/05 21-day 27.2 1/30-2/19/86 30-day 32.7 1/26-2/24/98 1 *Based on daily readings Cumulative Rainfall (inches) Rainfall Cumulative
0.1 1-DAY 2-DAY 3-DAY 7-DAY 14-DAY 21-DAY 30-DAY
0.01 0% 10% 20% 30% 40% 50% 60% 70% 80% Source: http://hurricane.ncdc.noaa.gov/dly/DLY Percent of Time Rainfall is Greater Than Figure 3-6 Frequency of Cumulative Daily to Monthly Rainfall at Ben Lomond, 1973-2006
BL4-Daily-Hist2.xls Fig 6/7/2007 4:19 AM NM Johnson 200% Santa Cruz
150%
100%
50% Annual Rainfall (% f avg) f (% Rainfall Annual
0% 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Water Years
200% Lockheed Facility
150%
100%
50% Annual Rainfall (% f avg) f (% Rainfall Annual
0% 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Water Years 200% Ben Lomond 4 Years with ≤75% average rainfall Years with 76-90% average rainfall 150% Apparent Santa Cruz upward trend partially explained by likely change(s) in station location pre-1950, as indicated by double mass curve analysis (Geomatrix, 1999). Since 1950, Santa Cruz upward trend continues while Lockheed trend becomes flat. 100% Significance of Ben Lomond upward trend uncertain due to short record length.
Source: see Tables 3-1 through 3-4. 50% Annual Rainfall (% f avg) f (% Rainfall Annual
0% Figure 3-7 1970 1980 1990 2000 2010 Water-Year Rainfall at Santa Cruz, Lockheed, and Ben Lomond Staions Water Years
Ppt-SC-LH6.xls Fig-WYs 5/18/2009 6:16 AM NM Johnson 225%
Santa Cruz
200% Lockheed Ben Lomond 4
175%
Maximum for Period 150%
125%
100%
Minimum
Moving-Average Rainfall (percent of average) for Period 75%
50%
25% 0 5 10 15 20 Length of Moving Average Period (yrs)
Moving-Average Minimums* Moving-Average Maximums* Yrs Santa Cruz Lockheed Santa Cruz Lockheed 1 35% 1924 37% 1924 213% 1941 226% 1890 2 52% 1976-77 48% 1976-77 182% 1940-41 189% 1982-83 3 62% 1869-71 53% 1929-31 171% 1940-42 159% 1982-84 *Color-coded by 4 66% 1928-31 59% 1928-31 162% 1940-43 145% 1995-98 common 5 67% 1987-91 62% 1927-31 149% 1940-44 140% 1982-86 overlapping periods. 6 71% 1987-92 63% 1926-31 145% 1938-43 139% 1995-00 7 73% 1869-75 65% 1924-30 141% 1937-43 130% 1995-01 8 74% 1924-31 62% 1924-31 138% 1936-43 127% 1995-02 9 74% 1869-77 65% 1923-31 133% 1937-45 123% 1978-86 10 77% 1868-77 66% 1922-31 131% 1936-45 123% 1965-74 12 78% 1869-80 69% 1921-31 126% 1995-06 122% 1995-06 Figure 3-8 14 79% 1918-31 67% 1920-31 123% 1993-06 118% 1993-06 Minimum and Maximum Moving- 16 80% 1916-31 69% 1919-21 122% 1937-52 116% 1969-84 20 80% 1869-88 72% 1916-35 117% 1937-56 116% 1967-86 Average Rainfall
Ppt-SC-LH4.xls FigMvAvg 6/7/2007 4:01 AM NM Johnson 200%
100%
1917-37 Drought 0% 1987-94 1975-77 Drought Drought -100%
Pre-1890 Drought -200% Average (% of average) Average (%
-300%
-400%
-500% Cumulative Departure from Departure Cumulative
Lockheed (entire record) Drought = downward segments -600% Santa Cruz (since 1889) Average period = flat segments Santa Cruz (entire record) Wet period = upward segments
-700% 1860 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Water Years Figure 3-9 Water-Year Rainfall Cumulative Departure from Average
Ppt-SC-LH6.xls FigCumDepAvg 5/18/2009 6:17 AM NM Johnson 8
3 8
Source: http://wwwcimis.water.ca.gov/cimis/info.jsp
6 Monthly CIMIS Reference Evapotranspiration for Santa Cruz County Zones ) Zone 1 -- Coastal Fog Belt Zone 2 --Coastal Mixed Fog 5 Zone 3 -- Coastal Valleys
4
3
2
1 Reference Evapotranspiration (ETo, inches 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Figure 3-10 CIMIS Reference Evapotranspiration for Central Coast Region
CIMIS Map2.xls CentralCoast 6/7/2007 4:20 AM 1 Pilarcitos Ck at Half Moon Bay 17 Carbonera Ck at Scotts Valley 2 Purisima Ck near Half Moon Bay 18 Branciforte Ck at Santa Cruz 3 San Gregorio Ck at San Gregorio 19 West Br. Soquel Ck near Soquel Palo 4 Pescadero Ck near Pescadero 20 Soquel Ck near Soquel 5 Butano Ck near Pescadero 21 Soquel Ck at Soquel Alto 6a Scott Ck above Little Ck 22 Aptos Ck near Aptos 6b Scott Ck near Davenport 23 Aptos Ck at Aptos 7 San Vicente Ck near Davenport 24 Corralitos Ck near Corralitos 8 Laguna Ck near Davenport 25 Corralitos Ck at Freedom 9 Majors Ck near Santa Cruz 26 San Francisquito Ck at Stanford University 10 San Lorenzo R at Waterman Switch 27 Saratoga Ck at Saratoga 11 Boulder Ck at Boulder Creek 28 Los Gatos Ck at Los Gatos 12 Bear Ck at Boulder Creek 29 Guadalupe Ck at Guadalupe 13 Newell Ck at Ben Lomond 30 Uvas Ck above Uvas Res near Morgan Hill 14 Zayante Ck at Zayante 31 Bodfish Ck near Gilroy 15 Bean Ck near Scotts Valley 32 Pescadero Ck near Chittenden 16 San Lorenzo River at Big Trees (See Table 3-8 for summary of gaged records)
Los Gatos
Morgan P a c Hill ifi c O c e a n SLVWD Diversions
Davenport
Figure 3-11 USGS Gaged Watersheds in Santa the Santa Cruz Mountains Region Cruz (adopted from Geomatrix, 1999) 30 Ben Lomond Mtn Adjusted to 1937-1996 average (Table 3-8) SLVWD diversion watershed estimate* Quail Hollow 25 Zaynte Soils Soil-Water Budget Estimates (Table 3-6)
Laguna
Carbonera Ben Lomond Boulder 20 Scott above Little San Vicente Bean Uvas SLRBT WB SoquelMajors Scott Soquel at SqLos Gatos Saratoga 15 Branciforte Bear Zayante Butano Corralitos at Cor Newell Soquel SLR at Waterman Switch Apots near Aptos near Sq Guadalupe Pescadero
San Gregorio Purisima 10 Aptos at Aptos San Francisquito Santa Cruz Corralitos at Fdm Pilarcitos
Watershed Average Unit Streamflow (in/yr) Unit Streamflow Watershed Average Bodfish 5 Pescadero
0 25 30 35 40 45 50 55 60 *Adopted from Geomatrix, 1999. Watershed Average Rainfall (in/yr) See Figure 3-11 for map of gaged watersheds. Figure 3-12 Correlation Between Estimated Mean Annual Rainfall and Unit Streamflow for USGS Gaged Streams in the Santa Cruz Mountains Region
ppt-q-4.xls Fig 6/7/2007 4:12 AM NM Johnson 300% San Lorenzo River at Big Trees* 250%
200%
150%
100%
Annual Streamflow (% f avg) 50%
0% 1930 1940 1950 1960 1970 1980 1990 2000 2010 *Adjusted (Table 3-9) Water Years 400% Pescadero Creek 350%
300%
250%
200%
150%
Annual Streamflow (% f avg) 100%
50%
0% 1950 1960 1970 1980 1990 2000 2010 Water Years Years with ≤50% average streamflow Years with 50-90% average streamflow Figure 3-13 Water-Year Streamflow of San Lorenzo River and Pescadero Creek Source: see Table 3-10.
Sec3 USGS-Gaged-Records2.xls Fig-WY 5/18/2009 6:34 AM NM Johnson 50 Pescadero Creek near Pescadero 40
30
20
10
0 25 Boulder Creek at Boulder Creek 20
15
10
5
0 15 San Lorenzo River at Waterman Switch
10
5
Mean Daily Streamflow (cfs) Streamflow Daily Mean 0 15 Zayante Creek at Zayante
10
5
0 150 San Lorenzo River at Big Trees
100
50
0 15 Bean Creek near Scotts Valley Oct-74 Oct-75 Oct-76 Oct-77 Oct-78 Oct-79 Oct-80 Oct-81 Oct-82 Oct-83 Oct-84 Oct-85 Oct-86 Oct-87 Oct-88 Oct-89 Oct-90 Oct-91 Oct-92 Oct-93 Oct-94
Plots show 1975-77 and 1987-94 droughts. 10 Note effect of October 1989 Loma Prieta earthquake.
Source: http://nwis.waterdata.usgs.gov/ca/nwis/sw 5
Figure 3-14 0 Mean Daily Streamflow, Selected Streams, WY's 1975-1995 Oct-88 Oct-89 Oct-90 Oct-91 Oct-92 Oct-93 Oct-94
Drought-HGs.xls Sheet1 6/7/2007 4:23 AM NM Johnson 300% '83 San Lorenzo River flow* vs Ben Lomond rainfall (WY's 1974-2006; dated) San Lorenzo River flow* vs Lockheed rainfall (WY's 1937-2006) 250% Boulder Creek flow vs Ben Lomond rainfall '82 (WY's 1977-1992) San Lorenzo River vs Lockheed wet- & dry- period averages (WY's 1937-2006) '06 '98 200% Gaged watershed averages (as % of average for all watersheds; Table 3-8, Fig. 3-12) '95 '86 Soil-water budget estimates (as % of average for all cases; Table 3-6) '78 150% '97 '74 '80
'96 '05
'00 '93 100% '04 '99 '84 '75 Water-Year Streamflow (% of average) '03 '02 '01 '79 50% '81 '92 '85 '87 '90 '91'94 '89 '76 '77 '88 0% 25% 50% 75% 100% 125% 150% 175% 200% Water-Year Rainfall (% of average) Figure 3-15 *At Big Trees gage; approx. adjustment for major diversions. Correlation Between Annual Rainfall and Unit Streamflow See Tables 3-8 & -10 for sources. Selected Periods of Gaged Record
USGS-Gaged-Records2.xls Fig-WY-Ppt-Q 6/7/2007 4:16 AM NM Johnson 175 40
Pescadero Creek, San Vicente Creek, 150 35 WY's 1952-2006 WY's 1970-1985 30 125
25 100 20 75 15 Stormflow Mean Daily Flow (cfs) Flow Daily Mean
Mean Daily Flow (cfs) Flow Daily Mean Stormflow 50 Baseflow 10 Baseflow
25 5
0 0 1-Oct 1-Nov 1-Dec 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep
30 80
San Lorenzo River 70 Boulder Creek, at Waterman Switch, 25 WY's 1977-1992 WY's 1969-1992 60
20 50
15 40
30 10 Mean Daily Flow (cfs) Flow Daily Mean Mean Daily Flow (cfs) Flow Daily Mean Stormflow Stormflow 20 Baseflow Baseflow 5 10
0 0 1-Oct 1-Nov 1-Dec 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep
45 40
40 Zayante Creek, 35 Bean Creek, WY's 1958-1992 35 WY's 1990-2006 30
30 25 25 20 20 15 15 Stormflow Mean Daily Flow (cfs) Flow Daily Mean Stormflow (cfs) Flow Daily Mean Baseflow Baseflow 10 10
5 5
0 0 1-Oct 1-Nov 1-Dec 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 400 Unit Streamflow* 350 San Lorenzo River Water- at Big Trees, Drain- shed Total Storm WY's 1937-2006 age Rain- * Baseflow Run- ET 300 Area fall (% of off Stream (mi2) (in/yr) Total) (in/yr) 250
200 Pescadero Ck 45.9 39.9 13.0 4.8 37% 8.2 27.0 150 San Vicente Ck 5.9 50.9 20.5 10.0 49% 10.5 30.4 Stormflow SLR at Waterman Switch 6.2 44.6 14.7 6.1 41% 8.6 29.9 Mean Daily Flow (cfs) Flow Daily Mean Baseflow 100 Boulder Ck 11.4 52.8 21.8 8.4 38% 13.4 30.9 Zayante Ck 11.1 43.8 14.9 5.2 35% 9.7 29.0 50 Bean Ck 9.0 43.7 18.1 6.8 38% 11.2 25.7 SLR at Big Trees 106.6 46.0 17.3 7.1 41% 10.2 28.7 0 *Normalized to 1937-2006; thus, values of total streamflow differ slightly from Table 3-8. 1-Oct 1-Nov 1-Dec 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep
Hydrographs are of average mean daily flow for indicated periods of record. Source: http://nwis.waterdata.usgs.gov/ca/nwis/sw Figure 3-16 Estimated Avearge Stormflow-Baseflow Hydrograph Separation, Selected Gaged Streams
Qb-summary2.xls Sheet1 6/7/2007 4:24 AM NM Johnson 75 ) 70
65 Santa Cruz y = -0.0168x + 69.006 60
55 y = 0.0369x + 55.841 50
45 Annual Average Temperature (oF y = 0.0907x + 42.677 40 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005
80 ) 75
70 y = 0.0175x + 73.479 Ben Lomond 4 65
60
55 y = 0.0071x + 58.552
50 y = -0.0033x + 43.623
Annual Average Temperature (oF 45
40 1970 1975 1980 1985 1990 1995 2000 2005
70 y = 0.0008x + 64.447 ) 65
60 San Gregorio 2SE y = 0.0075x + 54.278 55
50
y = 0.014x + 44.117 45 Annual Average Temperature (oF
40 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005
80 ) 75
70 y = -0.0112x + 72.561 65 Los Gatos 60
y = 0.0126x + 58.77 55
50
Annual Average Temperature (oF 45 y = 0.0366x + 44.972 40 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005
Source: www.wrcc.dri.edu/summary/climsmnca.html Figure 3-17 Annual Mean Temperature, Selected Stations, 1945-2005
Temp-SC.xls Sheet7 6/7/2007 4:25 AM NM Johnson From: CDWR, July 2006
0.55 Santa Cruz y = 0.001x + 0.2557 0.50 Lockheed y = 0.0013x + 0.2337
0.45
0.40
0.35
0.30
Coefficient of Variability 0.25
0.20 Source: see Table 3-4 0.15 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Water Years Figure 3-18 Coefficient of Variation for Moving 10-Year Periods of Annual Precipitaion, Study Area and Statewide, 1880's to Present
Ppt-SC-LH4.xls Fig-CoefVar 6/7/2007 4:04 AM NM Johnson