Temperature Modeling for Restoration

California Water and Environmental Modeling Forum

Bill Smith, MWH

February 2010

1 San Joaquin River Restoration Project

2 Water Operations – Calsim II

Monthly Model of SWP/CVP water operations

Defines the over-all system operation boundaries for all Restoration Alternatives

1922 - 2003

3 Monthly to Daily Conversion

Purpose: Develop a set of daily Millerton operations suitable for use in San Joaqin River routing and temperature modeling.

5 Uses the Daily Millerton Average Monthly Release

Reservoir Model 4

Developed for USJRBSI 3

Release 2

Monthly boundary conditions 1 from CalSim interpolated to 0 convert to daily Oct 1st15th Nov Nov 15th1stDec Dec 15th1st Date Perform a simplified daily routing

4 Water Operations – Daily Millerton Reservoir Model How it works – Start with initial storage plus SJR Inflow – Madera and FKC diversion (CalSim) – SJR Minimum Release (CalSim) Delivery Delivery “” “Flood” – SJR Snowmelt Pre-release (CalSim) – Fill Conservation Storage – “Flood” release to Madera, FKC up to capacity limits – “Flood” release to SJR up Minimum Required to 8,000 CFS channel Snowmelt capacity “Flood” (8000cfs) Spill – Fill Flood Control Storage – “Flood” spill to SJR 5 Water Operations – Daily Millerton Reservoir Model Results Final results are a set of daily Millerton Reservoir operations San Joaquin River Release Routing Example 50 600

45 500 40 400 35 300 30

25 200

20 100 Daily Release (TAF) Release Daily

15 (TAF) Storage Millerton 0 10 -100 5

0 -200 Oct-82 Nov-82 Dec-82 Jan-83 Feb-83 Mar-83 Apr-83 May-83 Jun -83 Jul-83 Aug-83 Sep-83 Oct-83

SJR Min SJR Snow SJR Rain Millerton Inflow Routed SJR Release SJR Channel Capacity Flood Control Storage Limit Final Storage Millerton Minimum Storage 6 Daily – CalSim Millerton Reservoir Release Comparison

CALSIM Vs Disaggregated Millerton Storage

600

500 Annual operations 400 match well 300

Storage (TAF) Storage 200

100 Daily CALSIM 0 10/1/21 10/1/31 10/1/41 10/1/51 10/1/61 10/1/71 10/1/81 10/1/91 10/1/01

Daily Vs CALSIM SJR Release 25000

Daily CALSIM SJR Channel Capacity Magnitude different from 20000 monthly to daily 15000 boundary condition process. Higher peaks Flow (cfs) 10000 in daily release is 5000 expected. 0 1921 1926 1931 1936 1941 1946 1951 1956 1961 1966 1971 1976 1981 1986 1991 19967 2001 Water Year Daily – Historical Millerton Reservoir Release Comparison Not expected to match exactly. Timing of peaks matches very well.

Historic Vs Daily Millerton Reservoir Release to San Joaquin River

40,000 Final Daily Historic 35,000

30,000

25,000

20,000 Flow (cfs) 15,000

10,000

5,000

0 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 8 Temperature – Millerton Reservoir

Purpose: Simulate San Joaquin River Release Temperature

• 2-D Reservoir Temperature Model based on CE-QUAL-W2 • Developed in support of USJRBSI • Hourly time step from 1980 through 2003

Outlet Spill

9 Temperature – Millerton Reservoir

• How it works – Computes temperature profile at – Use profile to compute release temperatures

Thermocline Cold Water Pool Cold Water

10 Temperature – Millerton Reservoir Release Temperatures • High, short spikes in maximum temperatures due to spills • Seasonal increase in Oct-Dec due to reduction in Cold Water Pool 80 Existing-Median Settlement-Median Existing-Max Settlement-Max 75

70

65

60

Temperature (ºF) Temperature 55

50

45

40 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep 1-Oct 1-Nov 1-Dec

11 Temperature – San Joaquin River Millerton Reservoir to Merced River • Purpose –Route daily flows and simulate San Joaquin River water temperatures • 1-D River Temperature Model based on HEC5Q • Hourly time step • 1980 through 2003

12 Temperature – San Joaquin FlowTurlock

Hills Ferry Me 5 rc Routing ed Barrier R iv er 4B How it works Mariposa BP 1 B Los Banos P Atwater ea B

r C HEC-5 routes flow e r

d e

4B i 2 ek Merced Sand s through the system t Slough s a

E • Flow splits at 4A Sack – Chowchilla Bypass Dam

– Mendota Bypass (With P Chowchilla Firebaugh 3 B

Project Only) a l l Mendota i h – Sand Slough Dam c w Mendota o h – Mariposa Bypass 2B C S Madera an 2A J • HEC-5Q simulates oa qu in Friant R temperatures of the Bifurcation 1B iv Dam Structure er flows Gravelly Ford 1A 13 Fresno Temperature – Sensitivity Studies

• Several sets of sensitivity studies were performed to frame the system temperature response. – Millerton release temperature w/wo restoration – SJR temperatures at different flow rates – Potential effects of increased riparian vegetation and channel modification on SJR temperatures * No Mendota Bypass in sensitivity modeling

14 Temperature – Sensitivity Studies _Flow Rate Impact on Temperature

90 Gravelly Ford Gravelly Friant Chowchilla Bypass Chowchilla

85 T=55 Q=350 T=50 Q=350 80 T=45 Q=350 T=55 Q=2,000 75 T=50 Q=2,000 70 T=45 Q=2,000 T=55 Q=4,500 65 T=50 Q=4,500 T=45 Q=4,500 60

Mariposa Bypass Mariposa Key: 55

Mendota Pool Mendota T: Friant Dam Merced River Merced Sand SloughSand

Salt Slough Salt Release Bear River Bear 50 S aDa c m k Temperature (degrees F) 45 Q: Friant Dam Release (cfs) Mean Daily Temperature in May (degrees F) 40 270 250 230 210 190 170 150 130 110 River Location (Mile Post)

Median of simulated temperatures in San Joaquin River (May)

15 Temperature – Sensitivity Studies _Flow Rate Impact on Temperature

90 Friant Dam Friant

85 T=62 Q=350 T=55 Q=350 80 T=50 Q=350 T=62 Q=700 75 T=55 Q=700 T=50 Q=700 70

65 Key: 60 T: Friant Dam

Chowchilla Bypass Chowchilla Release Mariposa Bypass Mariposa Temperature 55

Mendota Pool Mendota (degrees F) Gravelly Ford Gravelly Merced River Merced Sand Slough Sand

Salt Slough Salt Q: Friant Dam Stevinson 50 Dam Sack Release (cfs)

45 Mean Daily Temperature in August (degrees F) 40 270 250 230 210 190 170 150 130 110 River Location (Mile Post)

Median of simulated temperatures in San Joaquin River (August) 16 Temperature – Riparian and Channel Modification Impacts Increased Riparian Channel Modification

Reduces peak summer temperatures 3 -5 degrees but still at or over 80 F

Maintains biologically better temperatures 2-5 weeks later in the year.

Plots at Gravelly Ford, approximately 40 miles downstream of Millerton Lake

17 Temperature – Major Conclusions

• Ambient conditions are a very important factor in water temperatures. (It gets hot there!) • Flow is more effective in maintaining cooler water temperatures than release temperature • Equilibrium temperature is relatively independent from the flow. • Equilibrium temperature is usually attained in Reach 5 in winter/spring, reach 2B in summer and Reach 2A in the fall. • Riparian shading and channel modifications have limited potential for significant cooling in the Restoration Area 18