Temperature Modeling for San Joaquin River 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 Reservoir 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” “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 dam – Use profile to compute release temperatures Thermocline ColdPool 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 5 Me Routing rc 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 Friant Dam Chowchilla Bypass 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 Key: 55 Mendota Pool T: Friant Dam Merced River Sand Sand Slough Salt Slough Release Bear River 50 Dam Sack 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 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 Release Mariposa Bypass 55 Temperature Mendota Pool Gravelly Ford Merced River (degrees F) Sand Slough Salt Slough Q: Friant Dam Stevinson Sack Dam 50 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.