Appendix VIII. Completed regulated flow times series

Transcription

1 Appendix VIII. Completed regulated flow times series To develop regulated flow-frequency curves, the unregulated volume-duration-frequency curves are transformed through the unregulated-regulated flow transform process. The transform process captures the system s response to large, varied events, and is created using both the unregulated and regulated flow time series. To develop the regulated flow time series we took selected historical events from the unregulated flow time series and simulated those in the regulated system. In addition, scaled historical events were used to represent events larger than those seen in the historical record for definition of the flow transforms. We then compiled the maximum unregulated and regulated flows for various durations to develop the event maxima datasets needed for developing transforms. Top of Levee Modification for HEC-RAS for Existing Conditions The development of the original CVHS HEC-RAS models is described in Appendix II. The system HEC-RAS models described in Appendix II for the Sacramento and San Joaquin River basins were modified in the latter half of calendar year 2012 with a new top of levee profile that matched the new CVFED HEC-RAS models. This work was accomplished at the request of DWR and top of levee data was provided by CVFED. The modification of the HEC-RAS models was performed by a USACE contractor, David Ford Consulting Engineers. The modified HEC-RAS models were utilized by CVHS to develop regulated flow frequency curves for existing conditions. HEC-ResSim boundary conditions We used the HEC-ResSim models to simulate reservoir releases and hydrologically route flows throughout the system. HEC-ResSim boundary conditions are listed in Table 1 and 2 below. They can also be found in Appendix II. The development of the HEC-ResSim models is described in Appendix II. It should be noted that starting storages/elevations for the reservoirs were set to be consistent with those from the Sacramento and San Joaquin river basins comprehensive study (Comp Study), except for Lake Berryessa (Montecito Dam) where starting storage was modified (increased) to better match historic releases. Large releases can only be made from Lake Berryessa when the water surface reaches the invert of the ungated spillway (glory hole). As such, starting storage was modified for this dam. 1 HEC-RAS boundary conditions We used the HEC-ResSim models to simulate reservoir releases and hydrologically route flows throughout the system. Results from the HEC-ResSim models, as well as local flows, were then used to construct the regulated-condition HEC-RAS boundary condition files. To do this, we: 1. Configured the regulated flow time series from HEC-ResSim in the regulated-condition HEC-RAS models at the appropriate locations. Several of the regulated flow time series were developed upstream of the HEC-RAS model extents. For these, we used HEC- ResSim to hydrologically route the upstream hydrographs to an HEC-RAS handoff point. 2. Configured the unregulated local flows in the regulated-condition HEC-RAS boundary condition file.

2 The Sacramento River regulated-condition HEC-RAS model required upstream boundary conditions at 11 locations contained within CVHS local flow areas. To assign boundary condition flows to these locations, we distributed the total local flow for each area to the HEC-RAS upstream boundaries based on contributing areas. This eliminated the need to configure placeholder hydrographs to serve as the upstream boundary conditions. Local flows were distributed to these river reaches according to Table Configured placeholder hydrographs at the upstream boundaries of river reaches where no regulated time series or local flow time series were available to serve as the upstream boundary. The placeholder hydrographs were configured as flow hydrographs with a constant flow of 25 cfs. As stated above, the locations in the Sacramento River basin regulated HEC-RAS model where local flows were used as upstream boundary conditions are listed in Table 3. Table 44 and Table 5 list the flow boundary conditions for the Sacramento and San Joaquin river basin HEC-RAS models, respectively. In column 4 of Table 44 and Table 5, we list the source of each boundary condition, with comments describing selected boundary conditions in column 6. In column 5 of Table 44 and Table 5, we list the minimum flows for each reach that are required to run the model. Minimum flows have the potential to add volume to the system when flow in a reach is low and do add volume to the system where placeholder hydrographs are configured. Steps for Developing the Regulated Time Series This appendix describes the completion of the regulated times for CVHS. The regulated time series plays a key role in developing the unregulated to regulated transforms as described in the technical procedure portion of the main report. The transform describes the relationship between a specific unregulated flow volume and peak regulated flow, thus indicating how the system of reservoirs, levees, bypasses and other infrastructure impact and regulate natural floods. The transforms and unregulated flow frequency curves will be linked together to create regulated flow frequency curves. The steps needed to create the regulated flow times series include: 1. Selecting historic floods to scale and route through the regulated models. 2. Scaling the unregulated hydrographs 3. Routing the scaled hydrographs through the HEC-ResSim model 4. Routing HEC-ResSim output hydrographs and local flow hydrographs through HEC- RAS and collecting the output in DSS format files. 2 STEP 1 (Select historic floods to scale and route through the regulated models). Rare floods are of the greatest interest for CVHS and less is known about these events due to the limited period of time man has been recording these events. In the field of hydrology, it is commonly thought that historically rare floods are the best indicators of the characteristics of future rare floods not yet seen. Initially, USACE chose to use the 19 largest system-wide floods to occur in the Central Valley of California as the pattern floods to use for scaling and routing to develop the regulated time series. These floods are documented in the Historic Flood Event Matrices of the Sacramento and San Joaquin Comprehensive Study (Technical Studies Documentation, Appendix B, Attachment B.3, USACE 2002). Use of all these pattern floods was first attempted on the Calaveras River at

3 Bellota index point. The Bellota gage is downstream control point for New Hogan Dam. The unregulated hydrographs consisted of two parts: a) the unregulated inflow hydrograph to New Hogan Dam and b) the uncontrolled local flow hydrograph that emanates from the drainage area between the dam and the Bellota streamgage. The two original hydrograph pairs were scaled by various ratios and routed through an HEC-ResSim model for both unregulated and regulated conditions (reservoir turned off and reservoir turned on). We then compiled the maximum unregulated and regulated flows for various durations to develop the event maxima datasets needed for developing a transform. Critical duration was identified as 1-day for this index point. Plotting the data pairs (maximum 24-hour regulated flow versus peak flow for each scale factor and pattern, resulted in an unacceptable wide range of peak regulated flow versus 24-hour volume. The figure below shows an example of a regulated flow frequency curve derived using 8 pattern floods at Bellota. The 1-day day unregulated flow frequency curve was used along with the transform to develop the regulated flow frequency curve shown below. The variability in the plotted data pairs in the figure below was partially found to be a function of the local flow runoff between New Hogan Dam and Bellota. Further research showed that for the three rarest floods in this watershed for which local flow could be measured, the local flow hydrograph peak ranged from 4% to 9% of the total unregulated hydrograph (local flow peak divided by unregulated hydrograph peak). However, for much more common events, the local flow component ranged as high as 40%. It was realized that local flow characteristics vary as a function of the frequency and type of storm. 3 As the New Hogan Dam Water Control Manual directs the water manager to maintain a total combined flow (reservoir outflow plus local flow) of 12,500 cfs or less at the Bellota gage, the amount of local flow significantly impacted the reservoir s level of protection that it

4 could provide. Development of unregulated to regulated transforms based on too many historic pattern floods showed poor results. The above observation is believed largely due to the nature of atmospheric rivers which is a wide stream of moisture flowing eastward from the Pacific Ocean that combines with a cold front moving south from the northern latitudes. As the moving stream of moisture moves up and over the mountain ranges, the air is cooled causing condensation and high amounts of precipitation. Topographic induced precipitation is a phenomenon related to what meteorologist call orographic lift. Meteorologists state that the largest system-wide floods in this region are caused by atmospheric river events with significant orographic lift which increases the precipitation contribution at the higher elevations of the watershed, compared to the lower valley floor. Looking at a mean annual precipitation map shows the magnitude of variability between the mountains and the valley floor of the Central Valley. As such, a decision was made that CVHS would focus on a smaller handful of historic floods with the belief that these more accurately reflected the characteristics of extreme floods. This decision was consistent with a recent floodplain mapping study conducted by USACE on the Upper Mississippi River that used a similar procedure to CVHS. In that study, only three of the rarest observed floods recorded in that region were used as pattern floods upon which to develop the regulated time series. Dr. David Goldman (senior hydrologist at HEC) was involved in the development of the Mississippi River study procedure. Below is a discussion of the pattern floods adopted for CVHS for development of system-wide regulated flow frequency curves. Patterns chosen: For the Sacramento River, 4 historical event patterns were chosen: 1956, 1965, 1986, and For the San Joaquin River basin, 5 historical events were chosen: 1951, 1956, 1982, 1986, and While the 1982 event was run through the HEC-ResSim and HEC-RAS models, it ultimately was not used for the development of transforms. This was a late spring flood which occurred when the reservoir rule curves at the dams allow a reduction in the required flood control space due to the decreasing threat of significant storms as summer approaches. It was realized that a family of seasonal unregulated flow frequency curves would be required at every index location in the San Joaquin River basin in order to appropriately assign frequencies to the scaled floods using the 1982 pattern. As such, this pattern was not utilized in the final analysis. The 1951 event pattern was utilized on some of the tributaries in this watershed, but not for the mainstem river index locations, as it was a significantly more common flood within the basin as a whole. STEP 2: Scaling the unregulated hydrographs Appendix IX provides details on the scaling factors applied to the various model runs for each watershed. STEP 3: Routing the scaled hydrographs through the HEC-ResSim model 1. We configured the upstream and local flow hydrographs in the HEC-ResSim boundary condition file for both the Sacramento and San Joaquin river basin models as shown in the tables 1 and We configured the event simulation times for the floods of record events in the HEC-ResSim models. We configured 43 events for the Sacramento River basin and 37 events for the San Joaquin River basin. The events and simulation times for both basins are presented in Appendix IX.

5 3. We executed the HEC-ResSim models for each of the simulations and reviewed the results. The HEC-ResSim model had already undergone the Corps agency technical review (ATR) process. During this ATR process, the model configuration and reservoir simulation rules were reviewed. Thus, here we completed a limited review of the simulation results focusing instead on model execution and model stability. Details of this review are available upon request. STEP 4: Routing HEC-ResSim output hydrographs and local flow hydrographs through HEC-RAS and collecting the output in DSS format files. In order to run the HEC-RAS models, we performed the following: 1. Configured the HEC-ResSim results (reservoir releases) and local flows in the regulated HEC-RAS boundary condition files. Details of the boundary condition file configurations are included in Table 4 and Table 5. Note: It should be noted that we used the CVHS unregulated-condition HEC-RAS models to complete the unregulated flow time series. During the unregulated simulations, we modified the models, as needed, to improve model stability over a wide range of flows. The same modifications made to the unregulated models to facilitate model stability there were also made to the regulated models here. 2. Configured the event simulation times for the floods of record events in the regulated HEC-RAS models. 3. Specified model output locations in each simulation plan that correspond to analysis point locations. The locations can be found in Appendix II or in an Excel spreadsheet (AnalysisPointLocations.xlsx) relating HEC-RAS model cross sections to analysis points. 4. Configured constant stage hydrographs at the downstream boundaries of the HEC-RAS models. The chosen boundary conditions are shown in Table Executed the HEC-RAS models for each of the simulations and reviewed the results. For this, we again completed a review focusing on model exaction and model stability. We verified that each simulation ran to completion and that each maximum water surface profile computed was reasonable and without erratic changes in stage due to model instabilities. 6. Extracted the regulated flow time series from the regulated HEC-RAS and HEC-ResSim simulation results files for modeling nodes corresponding to CVHS analysis point locations. For this, we used the AnalysisPointLocations.xlsx spreadsheet. 7. Compiled the final sets of regulated flow time series using a combination of results from HEC-RAS and HEC-ResSim model simulations. For analysis points located outside of the HEC-RAS model extents, HEC-ResSim results are used to represent the regulated flow at the analysis points. 5

6 Table 1. HEC-ResSim unregulated boundary conditions for the Sacramento River basin Node name HEC-ResSim internal flow variable HEC-DSS B-part 1,2 Shasta_IN Sac SHASTA FLOW LOC Capay Local flow_2b 2_B Indian Valley_IN Inflow_NF Cache Indian Valley Dam NF_CACHE_CR@INDIAN_VALLEY_DAM Berryessa_IN BERRYESSA INFLOW PUTAH_CR@MONTICELLO_DAM Yolo Bypass KRC 0 Local flow A 1_A Black Butte_IN NF Stony BLB INFL Flow Loc STONY_CR@BLACK_BUTTE_DAM_55PCT_0HR_BLACK_BUTTE Stony Gorge_IN STONY GORGE FLOW LOC STONY_CR@BLACK_BUTTE_DAM_30PCT_4HR_STONY_GORGE East Park_IN EAST PARK FLOW RES IN STONY_CR@BLACK_BUTTE_DAM_15PCT_6HR_EAST_PARK Los Molinos NR LOS MOLINOS FLOW LOC MILL_CR_NR_LOS_MOLINOS Paskenta_Elder Cr Elder Creek near Paskenta ELDER_CR_NR_PASKENTA Vina Bridge NR VINA FLOW LOC DEER CR DEER_CR_NR_VINA Coleman Fish Hatchery BLW COLE FH FLOW LOC BATTLECR BATTLE_CR_BL_COLEMAN_FISH_HATCHERY_NR_COTTONWOOD Cottonwood NR COTTONWOOD FLOW LOC COTTONWOOD_CR_NR_COTTONWOOD Millville NR MELLVILLE FLOW LOC COW CR COW_CR_NR_MILLVILLE McCloud_IN MCCLOUD FLOW RES IN SACRAMENTO_R@SHASTA_DAM_13PCT_3HR_MCCLOUD Pit 7_IN PIT 7 FLOW LOC SACRAMENTO_R@SHASTA_DAM_05PCT_1HR_PIT_NO_7 Pit 6_IN PIT 6 FLOW LOC SACRAMENTO_R@SHASTA_DAM_10PCT_2HR_PIT_NO_6 Britton_IN BRITTON FLOW RES IN SACRAMENTO_R@SHASTA_DAM_42PCT_6HR_LAKE_BRITTON Chico BUTTE NR CHICO FLOW LOC BUTTE_CR_NR_CHICO Butt Valley_IN BUTT VALLEY FLOW RES IN FEATHER_R@OROVILLE_DAM_02PCT_4HR_BUTT_VALLEY Almanor_IN NF Fea R ALMANOR FLOW LOC FEATHER_R@OROVILLE_DAM_08PCT_4HR_LAKE_ALMANOR 6

7 Node name HEC-ResSim internal flow variable MOUNTAIN MEADOWS FLOW RES IN HEC-DSS B-part 1,2 Mountain Meadows_IN Antelope_IN ANTELOPE INFLOW SF Tunnel_Lost Creek SLY CREEK INFLOW Deer Cr Nr Smartsville DEER NR YUBA FLOW LOC DEER_CR_NR_SMARTVILLE_70PCT_0HR_SMARTVILLE New Bullards Bar_IN NEW BULLARDS BAR FLOW RES IN Scotts Flat_IN SCOTTS FLAT FLOW RES IN DEER_CR_NR_SMARTVILLE_30PCT_2HR_SCOTTS_FLAT Jackson Meadows_IN JACKSON MEADOWS FLOW RES IN MF+SF_YUBA_R_05PCT_6HR_JACKSON_MEADOWS Bowman_IN BOWMAN FLOW RES IN MF+SF_YUBA_R_05PCT_5HR_BOWMAN_LAKE Spaulding_IN SF Yuba R SPAULDING FLOW RES IN MF+SF_YUBA_R_25PCT_5HR_SPAULDING_LAKE Fordyce_IN FORDYCE FLOW RES IN MF+SF_YUBA_R_05PCT_6HR_FORDYCE_CREEK Oroville_IN MF Fea R OROVILLE FLOW LOC FEATHER_R@OROVILLE_DAM_80PCT_0HR_OROVILLE Little Grass Valley_IN LITTLE GRASS VALLEY INFLOW FEATHER_R@OROVILLE_DAM_02PCT_2HR_LITTLE_GRASS_VALLEY Bucks_IN BUCKS LAKE INFLOW FEATHER_R@OROVILLE_DAM_02PCT_2HR_BUCKS_LAKE Davis_IN DAVIS INFLOW FEATHER_R@OROVILLE_DAM_01PCT_4HR_LAKE_DAVIS Frenchman_IN FRENCHMAN INFLOW FEATHER_R@OROVILLE_DAM_01PCT_6HR_FRENCHMAN_LAKE UNET Honcut FTH 44 Local flow A 27_A Camp Far West_IN CAMP FAR WEST INFLOW BEAR_R_NR_WHEATLAND_62PCT_2HR_CAMP_FAR_WEST Rollins_IN COMBINED ROLLINS INFLOW BEAR_R_NR_WHEATLAND_36PCT_7HR_ROLLINS Loon Lake_IN LOON LAKE INFLOW AMERICAN_R@FOLSOM_DAM_01PCT_(HIST_POST WY1921)_6HR_LOON_LAKE Hell Hole_IN HELL HOLE INFLOW AMERICAN_R@FOLSOM_DAM_04PCT_(HIST_POST WY1921)_6HR_HELL_HOLE French Meadows_IN FRENCH MEADOWS INFLOW AMERICAN_R@FOLSOM_DAM_03PCT_(HIST_POST WY1921)_5HR_FRENCH_MEADOW Ice House_IN ICE HOUSE INFLOW AMERICAN_R@FOLSOM_DAM_01PCT_(HIST_POST WY1921)_6HR_ICE_HOUSE 7

8 Node name HEC-ResSim internal flow variable HEC-DSS B-part 1,2 WY1921)_5HR_UNION_VALLEY Union Valley_IN UNION VALLEY INFLOW Bend Bridge Bend Bridge local 84_A Sac R + Mill Cr SAC 229 Local flow B 42_47_45_B UNET Vina Br SAC 218 Local flow C 42_47_45_C Above Westside Overflow_DIV Confluence Local flow A 40_41_A Dry Cr + Yuba R YUB 14 Local flow A 10_A Bear R + Feather R FTH 12 Local flow A 25_A Abv Feather R + Yuba R FTH 30 Local flow B 27_B Above Fremont Weir_DIV Sac R + American R Local 17_A 17_A Below Paskenta ELD 6 Local flow E 42_47_45_E Above SacR + Big Chico Cr SAC 199 Local flow D 42_47_45_D Below Westside Confluence local flow B 40_41_B Meridian SBY 1 Local flow A 29_A Below Meridian WDC 0 Local flow A 24_A Whiskeytown Keswick_IN WHISKEYTOWN FLOW RES IN CLEAR_CR_NR_IGO Folsom_IN NF Amer Folsom_IN SF Amer FOLSOM LOCAL INFLOW AMERICAN_R@FOLSOM_DAM_86PCT_(HIST_POST WY1921)_0HR_FOLSOM_LAKE Above Sac R + Elder Cr Local_42_47_45_A 42_47_45_A U_S Rumsey Local flow_2a 2_A 8

9 Node name HEC-ResSim internal flow variable Clear Lake to Grigsby Riffle Inflow into Clear Lake 1. Unregulated headwater flows are from the file _Reg_HW.dss provided by the Corps. 2. Local flows are from the file _Unreg_BC.dss provided by the Corps. HEC-DSS B-part 1,2 9

10 Table 2. HEC-ResSim boundary conditions for the San Joaquin River basin Node name HEC-ResSim internal flow variable HEC-DSS B-part 1,2 Sly Park_IN Sly Park Inflow Michigan Bar Michigan Bar Local Flow Lower Bear_IN Lower Bear Inflow Salt Springs_IN Salt Springs Inflow New Spicer Meadows_IN New Spicer Meadows Inflow Donnells_IN Donnells Inflow Beardsley_IN Beardsley Inflow Cherry Valley_IN Cherry Valley Inflow Eleanor_IN Eleanor Eleanor Inflow Eleanor Eleanor_IN Kibble Eleanor Inflow Kibble Hetch Hetchy_IN Hetch Hetchy Inflow Don Pedro_IN Don Pedro Inflow New Melones_IN New Melones Inflow New Hogan_IN New Hogan Inflow Pardee_IN Pardee Inflow Camanche_IN Camanche Inflow Farmington_IN Farmington Inflow Duck Ck nr Farmington Duck Ck nr Farmington Inflow DUCK_CR_NR_FARMINGTON Below Farmington Area 61 Local Flow A 61_A Owens_IN Owens Inflow OWENS_CR@OWENS_CR_DAM Ripon Area 67 Local Flow C 67_C Blw Orange Blossom Bridge Area 67 Local Flow B 67_B 10

11 Node name HEC-ResSim internal flow variable HEC-DSS B-part 1,2 Abv Orange Blossom Bridge Area 67 Local Flow A 67_A New Exchequer_IN New Exchequer Inflow MERCED_R@NEW_EXCHEQUER_DAM Burns_IN Burns Inflow BURNS_CR@BURNS_CR_DAM Bear_IN Bear Inflow BEAR_CR@BEAR_CR_DAM Mariposa_IN Mariposa Inflow MARIPOSA_CR@MARIPOSA_CR_DAM Buchanan_IN Buchanan Inflow CHOWCHILLA_R@BUCHANAN_DAM Bass_IN Bass Inflow SAN_JOAQUIN_R@FRIANT_DAM_03PCT_3HR_BASS Mammoth_IN Mammoth Inflow SAN_JOAQUIN_R@FRIANT_DAM_38PCT_3HR_MAMMOTH Florence_IN Florence Inflow SAN_JOAQUIN_R@FRIANT_DAM_07PCT_7HR_FLORENCE Thomas A. Edison_IN Thomas A. Edison Inflow SAN_JOAQUIN_R@FRIANT_DAM_03PCT_6HR_EDISON Huntington_IN Huntington Inflow SAN_JOAQUIN_R@FRIANT_DAM_05PCT_2HR_HUNTINGTON Shaver_IN Shaver Inflow SAN_JOAQUIN_R@FRIANT_DAM_03PCT_1HR_SHAVER Redinger_IN Redinger Inflow SAN_JOAQUIN_R@FRIANT_DAM_16PCT_1HR_REDINGER Courtright Wishon_IN Courtright Wishon Inflow KINGS_R@PINE_FLAT_DAM_10PCT_2HR_COURTIGHT_WISHON Friant_IN Friant Inflow SAN_JOAQUIN_R@FRIANT_DAM_25PCT_0HR_MILLERTON Big Dry Creek_IN Big Dry Creek Inflow BIG_DRY_CR@BIG_DRY_CR_DAM Hidden_IN Hidden Inflow FRESNO_R@HIDDEN_DAM Black Rascal Div Black Rascal Div Local Flow BLACK_RASCAL_DIV Cressey 71_73_74A 71_73_74_A Abv SJQ + Los Banos Area 86 Local Flow J 86_76_J Blw SJQ + Los Banos Area 86 Local Flow I 86_76_I Fremont Ford Bridge Area 76 Local Flow A 86_76_A Newman Area 86 Local Flow C 86_76_C Los Banos_IN Los Banos Inflow LOS_BANOS_CR@LOS_BANOS_DAM 11

12 Node name HEC-ResSim internal flow variable HEC-DSS B-part 1,2 Orestimba nr Newman Orestimba nr Newman Local Flow ORESTIMBA_CR_NR_NEWMAN SJQ + Orestimba Area 68 Local Flow A 68_A Del Puerto nr Patterson Del Puerto nr Patterson Local Flow DEL_PUERTO_CR_NR_PATTERSON Abv SJQ + Tuolumne 68_C 68_C Modesto Gage Area 90 Local Flow B 90_B Dry Ck nr Modesto Dry_Cr_at_Modesto DRY_CR@MODESTO Abv Dry Break Div Abv Dry Break Local Flow DRY CR ABV DRY BREAK DIV DUMMY Abv Bellota Area 59 Local Flow A 59_A Abv Berenda Div 86_76_G 86_76_G Pine Flat_IN Pine Flat Inflow KINGS_R@PINE_FLAT_DAM_90PCT_0HR_PINE_FLAT Mill Ck at Piedra 53_101_102_A 53_101_102_A Blw Bear Ck + Black Rascal 96_A 96_A Tuolumne handoff 90_A 90_A Littlejohn + Lone Tree Ck 58_A 58_A Abv Del Puerto 68_B 68_B Blw SJQ + James Bypass 86_76_L 86_76_L Cosumnes_DIV return Cosumnes_DIV return COSUMNES_DIV RETURN DUMMY Owens_DIV return Area 86 Local Flow E 86_76_E Crescent Weir_DIVreturn Crescent Weir_DIV return dummy CRESCENT WEIR_DIV RETURN DUMMY 1. Unregulated headwater flows are from the file _Reg_HW.dss provided by the Corps. 2. Local flows are from the file _Unreg_BC.dss provided by the Corps. 12

13 Table 3. Locations in the Sacramento River basin regulated HEC-RAS model where local flows were used as upstream boundary conditions Watershed where local flows were developed Local flow ID HEC-RAS boundary location Percent of total local flow distributed to reach 1 (4) Honcut Creek and Jack Slough 27_A SARobinsons _B Jack Slough 100 Bear River 25_A SA Reeds Cr 2 38 Best Slough 16 Dry Creek 31 SA Yankee 2 15 Pleasant Grove Creek, Steelhead 17_A SA Cross Canal 2 63 Creek, Dry Creek, and Arcade Creek NEMDC (at analysis point STL-12) 5 NEMDC (at analysis point STL-5) 3 22 NEMDC (at analysis point STL-2)3 10 Colusa Basin Drain 1_A KLRC Percentages are based on the contributing watershed area upstream and along the river reach. 2. Flow hydrographs are configured to flow into storage areas. Flow hydrographs were configured as lateral inflow hydrographs to the NEMDC reach. 13

14 Table 4. Regulated flows from HEC-ResSim and unregulated local flows used to construct the regulated HEC-RAS boundary condition file for the Sacramento River basin Stream name HEC-RAS boundary location River reach River station Source of inflow time series 1 (4) American River Reach 1 22 American River at Folsom Dam Minimum flow (cfs) 2 (5) 200 Comments (6) Bear River Upper Bear River near Wheatland 50 Best Slough Main 1.25 Local flow 25_A 25 16% of local flow 25_A was distributed to this reach. Butte Basin Main Placeholder 200 Butte Basin Main Butte Creek near Chico was hydrologically routed to analysis point BUT-27. Butte Basin Main 1.29 Local flow 29_A Cache Creek Main Cache Creek at Clear Lake, North Fork Cache Creek at Indian Valley Dam, Bear Creek near Rumsey, local flow 2_A, local flow 2_B 100 and unregulated local flow were hydrologically routed to the Cache Creek at Yolo gage. Cache Slough RM24.0 to US Placeholder 25 Dry Creek Main 7.59 Local flow 25_A 50 31% of local flow 25_A was distributed to this reach. Feather River Upper Feather River at Oroville 1,500 Dam Haas Slough Reach Placeholder 25 Jack Slough Reach Local flow 27_B 25 KLRC Reach Local flow 1_A

15 Stream name HEC-RAS boundary location River reach River station Source of inflow time series 1 (4) Minimum flow (cfs) 2 (5) Comments (6) Lindsey Slough Reach Placeholder 25 NEMDC Reach Local flow 17_A 175 5% of local flow 17_A was distributed to this reach. NEMDC Reach Local flow 17_A NEMDC Reach Local flow 17_A Putah Creek Upper Reach Putah Creek at Monticello Dam 22% of local flow 17_A was distributed to this reach. 10% of local flow 17_A was distributed to this reach. 100 Putah Creek near Davis gage. Sac Bypass Reach Placeholder 50 Sacramento Redding Sacramento River at Shasta Dam Sacramento Redding Clear Creek near Igo Sacramento Redding Cow Creek near Millville Sacramento Redding Cottonwood Creek near Cottonwood Sacramento Redding Battle Creek below Coleman Fish Hatchery near Cottonwood 2,000 Sacramento River. Sacramento River. Sacramento River. Sacramento River. Sacramento Redding Local flow 84_A Sacramento Redding Local flow 42_47_45_A 15

16 Stream name HEC-RAS boundary location River reach River station Source of inflow time series 1 (4) Sacramento Redding Elder Creek near Paskenta, local flow 42_47_45_E Minimum flow (cfs) 2 (5) Comments (6) and unregulated local flow were hydrologically routed to the Sacramento River. Sacramento Redding Local flow 42_47_45_B Sacramento Redding Mill Creek near Los Molinos Sacramento River. Sacramento Redding Dear Creek near Vina Sacramento River. Sacramento Redding Local flow 42_47_45_C Sacramento Redding Local flow 42_47_45_D Sacramento Redding Local flow 40_41_A Sacramento Redding Local flow 40_41_B Sacramento Redding 190 Stony Creek at Black Butte Dam Sacramento River. Sacramento DWSC Reach Placeholder 100 Sutter Bypass Colusa_to_Bu ttes Placeholder 200 Tisdale Bypass Tisdale 4.36 Placeholder 100 Wadsworth Canal Wadsworth 4.29 Local flow 24_A 25 Willow Slough Reach Placeholder 100 Yolo Bypass Reach Placeholder 500 Yuba OB Patrol 2.26 Placeholder 25 16

17 Stream name HEC-RAS boundary location River reach River station Source of inflow time series 1 (4) Minimum flow (cfs) 2 (5) Comments (6) Yuba OB Upper 4.87 Placeholder 25 Yuba OB Low spill 1.43 Placeholder 25 Yuba R Upper 22 Yuba River at Englebright Dam, Deer Creek near Smartville 50 Yuba River HEC-RAS handoff point. Yuba R Upper Local flow 10_A SA Cross Canal 3 Local flow 17_A 25 63% of local flow 17_A was distributed to this reach. SA Reeds Cr 3 Local flow 25_A 38% of local flow 25_A was 50 distributed to this reach. SA Yankee 3 Local flow 25_A 15% of local flow 25_A was 50 distributed to this reach. SaRobinsons 3 Local flow 27_A Placeholder hydrographs are required at the upstream cross section of reaches where no regulated time series or local flows are available. 2. Minimum flows are not required and were not specified where lateral inflows enter a river reach. Flows in bold are locations where placeholder hydrographs are configured. 3. Flow hydrographs are configured to flow into storage areas. 17

18 Table 5. Regulated flows from HEC-ResSim and unregulated local flows used to construct the regulated HEC-RAS boundary condition file for the San Joaquin River basin Stream name HEC-RAS upstream boundary River reach River station Source of inflow time series 1 (4) Ash Reach Chowchilla River at Buchanan Dam, local flow 86_76_G Berenda Reach Chowchilla River at Buchanan Dam, local flow 86_76_G Minimum flow (cfs) 2 (5) Comments (6) 25 and unregulated local flow were hydrologically routed to a diversion, where 60% of the flow goes to Ash Slough. Flow was then hydrologically routed to the Ash Slough HEC-RAS handoff point. 100 and unregulated local flow were hydrologically routed to a diversion, where 40% of the flow goes to Berenda Slough. Flow was then hydrologically routed to the Berenda Slough HEC-RAS handoff point. Dry Cr Reach Dry Creek at Modesto 25 FRERIV REACH Fresno River at Hidden Dam, local flow 86_76_H 100 and unregulated local flow were routed to the Fresno River HEC- RAS handoff point. 18

19 Stream name HEC-RAS upstream boundary River reach River station Source of inflow time series 1 (4) FRESL Reach Kings River at Pine Flat Dam, local flow 53_101_102 Minimum flow (cfs) 2 (5) Comments (6) 25 and unregulated local flow were hydrologically routed to the HEC- RAS handoff point in James Bypass. 50% of the flow is diverted to Tulare Lake Basin near the Army and Crescent weirs along the Kings River. FRESL Reach Local flow 86_76_L MAR BYP Reach Placeholder 50 Merced Reach Merced River at New Exchequer Dam, local flow 71_73_74_A 25 and unregulated local flow were hydrologically routed to the HEC- RAS handoff point on the Merced River. PARAD Reach Placeholder 50 SJR1 Reach San Joaquin River At Friant Dam SJR1 Reach Big Dry Creek Dam San Joaquin River. SJR1 Reach Local flow 86_76_N SJR1 Reach Local flow 86_76_O SJR1 Reach Local flow 86_76_M SJR18 Reach Los Banos Creek at Los Banos Dam 250 San Joaquin River. SJR18 Reach Local flow 86_76_J 19

20 Stream name HEC-RAS upstream boundary River reach River station Source of inflow time series 1 (4) Minimum flow (cfs) 2 (5) Comments (6) SJR18 Reach Local flow 86_76_I SJR18 Reach Local flow 86_76_A SJR18 Reach Local flow 86_76_C SJR20 Reach Local flow 68_A SJR20 Reach Local flow 68_B SJR20 Reach Del Puerto Creek near Patterson San Joaquin River. SJR3 Reach Local flow 86_76_K SJR3 Reach Local flow 86_76_P SJR30 Reach Duck Creek near Farmington, Littlejohns Creek at Farmington Dam, local flow 59_A, local flow 61_A San Joaquin River. SJR4 Reach Placeholder 50 Stanis Reach Stanislaus River at Melones Dam, local flow 67_A, local flow 67_B, local flow 67_C TUOLO1 Reach Tuolumne River at Don Pedro Dam 25 and unregulated local flow were hydrologically routed to the HEC- RAS handoff point on the Stanislaus River. 50 HEC-RAS handoff point on the Tuolumne River. TUOLO1 Reach Local flow 90_A TUOLO1 Reach Local flow 90_B 20

21 Stream name HEC-RAS upstream boundary River reach River station Source of inflow time series 1 (4) Minimum flow (cfs) 2 (5) Comments (6) TUOLO2 Reach Local flow 68_C UBYP5 Reach Placeholder 250 SA 3 3 Placeholder 50 SA 85 3 Bear Creek at Bear Creek Dam, Burns Creek at Burns Creek Dam, Black Rascal diversion, local flow 96_A, local flow 86_76_D SA 42 3 Owens Creek at Owens Creek Dam, Mariposa Creek at Mariposa Creek Dam, local flow 86_76_E SA 49 3 Orestimba Creek near Newman 50 and unregulated local flow were hydrologically routed to the storage area just upstream of the Bear River model reach. 50 and unregulated local flow were hydrologically routed to the storage area just upstream of the Owens River model reach. storage area along the San Joaquin River. 1. Placeholder hydrographs are required at the upstream cross section of reaches where no regulated time series or local flows are available. 2. Minimum flows are not required and were not specified where lateral inflows enter a river reach. Flows in bold are locations where placeholder hydrographs are configured. 3. Flow hydrographs are configured to flow into storage areas. 21

22 HEC-RAS downstream boundary conditions Both the Sacramento River and San Joaquin River regulated HEC-RAS models discharge into the Sacramento-San Joaquin Delta. With coordination and input from Corps staff and the CVHS project team, we used constant stage hydrographs to represent the downstream boundary conditions for this set of flow routing simulations. Boundary conditions were chosen to provide model stability for a wide range of flows and limit backwater in the system. The downstream boundary conditions for the Sacramento River basin model are listed in Table 3, and the downstream boundary conditions for the San Joaquin River basin model are listed in Table 4. [These boundary conidtion values are the same as those used for developing the unregulated flow time series.] These selected boundary conditions are not necessarily applicable for stagefrequency curve development in the lower reaches of the system. These stage-frequency curves, and the required simulations to do so, are part of a different task of CVHS. Table 3. Downstream boundary conditions for the Sacramento River basin regulated-condition HEC-RAS model Downstream boundary reach Sacramento River Georgiana Slough Three Mile Slough Downstream boundary condition 1 Stage = 1 ft Stage = 1 ft Stage = 1 ft 1. Stage is with respect to National Geodetic Vertical Datum of 1929 (NGVD 29). Table 4. Downstream boundary conditions for the San Joaquin River basin regulated-condition HEC-RAS model Downstream boundary San Joaquin River Middle River Grant Line Canal Old River Downstream boundary condition 1 Stage = 2 ft Stage = 0 ft Stage = 3 ft Stage = 2 ft 1. Stage is with respect to North American Vertical Datum of 1988 (NAVD 88). 22