U.S. Bureau of Reclamation Lahontan Basin Area Office Carson City, - PowerPoint PPT Presentation

U.S. Bureau of Reclamation Lahontan Basin Area Office Carson City, NV Water Supply Outlook January 19, 2016 Presented by: Nadira Kabir, Ph.D., P.E.

Outline • Current Conditions • NRCS/RFC Forecasted Data • Model for Forecasting Basin Outlook • 2016 Preliminary Outlook 2 1/19/2016

LOWER HUMBOLDT RYE PATCH REGION WINNEMUCCA Pyramid Lake RESERVOIR LAKE (dry) Indian Reservation HUMBOLDT RIVER PYRAMID LAKE TOULON LAKE PYRAMID MARBLE BLUFF LAKE Humboldt Wildlife Stillwater Nixon HUMBOLDT Management Area NWR LAKE Derby Fernley Dam TRUCKEE RIVER STAMPEDE TRUCKEE Fallon INDEPENDENCE CANAL Reno/Sparks Fallon Indian Newlands Reservation BOCA Project LAHONTAN PROSSER MARTIS DONNER Carson CARSON CARSON City LAKE RIVER Tahoe City Walker River Indian LAKE TAHOE Reservation WALKER Yerington RIVER Schurz TOPAZ LAKE WALKER LAKE 3 1/19/2016

Water Year 2015 Precipitation % of Normal 10/1/2014 – 3/17/2015 4 1/19/2016

Current WY Precipitation To Date 5 1/19/2016

Current Snowpack 6 1/19/2016

Lake Tahoe Snowpack Per Year 7 1/19/2016

Great Basin Snowpack January 2015 January 2016 8 1/19/2016

Historical & Forecasted Apr-Jul Runoff by Basin 9 1/19/2016

Historical & Forecasted A-J Runoff - Truckee 10 1/19/2016

Historical & Forecasted A-J Runoff - Carson 11 1/19/2016

12 1/19/2016

RiverWare Modeling for Water Management Truckee Carson River Model Development : 1.Ops Model: Day-to-day Operation 2.Planning Model – Long-term Reliability/Evaluation – Joint effort between Reclamation and TROA Implementation Office (Water Master’s Office) – for the Operations Model – Stakeholders Input Model Includes: • Supply (Inflows) • Demand (water rights, etc.) • Operating Criteria – Pre-TROA: Based on 1935 Truckee River Agreement (TRA) – Current: Truckee River Operating Agreement (TROA) 13 1/19/2016

Operation Criteria • General Electric Decree (1915) • Truckee River Agreement (1935) • Orr Ditch Decree (1944) • Donner Lake Agreement (1943) • Tahoe-Prosser Exchange (1959) • Interim Storage Agreement (1994) • Adjusted OCAP – Operating Criteria and Procedure (1997) 1/19/2016 14

Truckee River Operating Agreement: TROA • New Operating Policy: TROA – Negotiated pursuant to PL 101-618 (1990) – Partially implemented on December 1, 2015 – Full implementation – coming soon • TROA Builds on current Truckee River Agreement policy – Adds operational flexibility • Users may hold back their water as “credit water” • Allows for system of exchanges between reservoirs 15 1/19/2016

Reservoir Characteristics • Storage capacity • Max Min Pools • Outlet works • Spillway capacity • Storage Priority • Flood Control Operations • Evaporation • Precipitation • Power Prosser Reservoir 16 1/19/2016

RiverWare Model Development TROA Pre-TROA Operations Model Operations Model (15 months) (15 months) Planning Model Planning Model (100 year) (100 year) 17 1/19/2016

Ops Model for Water Management Operation – Day-to-day Operations and Look Ahead – Short-term Model – 15 months hydrology – Operational forecasts for stakeholders since 2004 – Inflow – Current Gage and Forecasted Model Use: – Water Master – Daily operations and TROA Scheduling Committee – Reclamation - Truckee Canal Diversion operations & Lahontan Flood operations 18 1/19/2016

RiverWare Framework • Node-based river system operations model • Physical characteristics • Uses rule-based simula tion - policy is coded in the rule set 19 1/19/2016

RiverWare Operations Model - Forecasted Inflow Methodology • NRCS/RFC April-July runoff volume forecasts for 3 basins: - Tahoe, Truckee, and Carson. • Forecasts are given as probability of exceedance: Lake Tahoe Gage - 10%, 30%, 50%, 70% , and 90% • Obtain inflow hydrograph patterns - volumes are matched to historically similar years • Disaggregate hydrographs to several basin locations • Model is run for each exceedance value 20 1/19/2016

LBAO Forecasting What forecasts we produce and why • OCAP Forecasts  Truckee Canal Operations – Lahontan Monthly Target Storages • Ft. Churchill Apr-Jul Volume • Carson Division Annual Demand – Truckee Canal Monthly Diversions • Truckee and Carson Division Monthly Demand • Truckee Canal Monthly Losses • Lahontan Reservoir Monthly Losses 21 1/19/2016

LBAO Forecasting What forecasts we produce and why • Forecasts  Truckee Basin Operations – Reservoir Filling/Flood Control Operations – Reservoir Operations to meet Floriston Rates – Tahoe-Prosser Exchange – Truckee Meadows Diversions and Demands – Fish and Wildlife Service Fish Releases – Truckee Canal Operations – Pyramid Lake Elevations • TROA Operational Forecasting Using RiverWare – TROA Administrator – Parties to submit a schedule - coordination process 22 1/19/2016

WY 2016 January 14 Forecast - Hydrograph Farad AJ Vol Carson AJ Vol Tahoe Gate (KAF) (KAF) Closed Rise (ft) 20% (W) 346 263 2.2 50% (M) 245 175 1.1 80% (D) 128 94 0.4 23 1/19/2016

Average & Forecasted Farad Flow 24 1/19/2016

Observed and Forecasted Reservoir Storage 25 1/19/2016

WY 2016 Storage Preliminary Projection - Tahoe 26 1/19/2016

WY 2016 Storage Preliminary Projection - Stampede 27 1/19/2016

WY 2016 Storage Preliminary Projection - Lahontan 28 1/19/2016

End! Comments? Questions?

Truckee River Agreement-1935 The TRA is the basis for pre-TROA operation of Lake Tahoe, Boca Reservoir, and the Truckee River. A slightly modified version of the original Floriston Rates Agreement was subsequently incorporated into the Truckee River Agreement. This included Reduced Floriston Rates. Lake Tahoe Elevations Oct. Nov.-Feb. March Apr.-Sept. Less than 6225.25 feet 400 300 300 500 6225.25 to 6226.00 feet 400 350 350 500 Over 6226.00 feet 400 400 500 500 Parties to the TRA include: TCID, SPPC (TMWA), and WCWCD 30 1/19/2016

WY 2015 Projection – Lake Tahoe Release Combined Forecast Lake Tahoe--Release 3/17/2015 30% Outflow 50% Outflow 70% Outflow 1.2 20 1.0 16 Mean Monthly Relaese (CFS) 0.8 13 Release (kAF) 0.6 10 0.4 7 0.2 3 0.0 0 Jan-15 Feb-15 Mar-15 Apr-15 May-15 Jun-15 Jul-15 Aug-15 Sep-15 Oct-15 Nov-15 Dec-15 31 1/19/2016

WY 2015 Projection – Farad Gage Flow Combined Forecast Truckee River at Farad--Gage Flow 3/17/2015 800 30% Flow 50% Flow 700 70% Flow 600 Floriston Rate_50% Mean Monthly Flow (cfs) "Floriston Rates_70% 500 "Floriston Rates_30% 400 300 200 100 0 Jan-15 Feb-15 Mar-15 Apr-15 May-15 Jun-15 Jul-15 Aug-15 Sep-15 Oct-15 Nov-15 Dec-15 32 1/19/2016

WY 2015 Projection – Nixon Gage Flow Combined Forecast Truckee River at Nixon--Gage Flow 3/17/2015 350 30% Flow 300 50% Flow 70% Flow Mean Monthly Flow (cfs) 250 200 150 100 50 0 Jan-15 Feb-15 Mar-15 Apr-15 May-15 Jun-15 Jul-15 Aug-15 Sep-15 Oct-15 Nov-15 Dec-15 33 1/19/2016

WY 2012-present Nixon Gage Flow 34 1/19/2016

WY 2015 Project – Prosser Storage Combined Forecast Prosser Reservoir--Storage 3/17/2015 14 30% Storage 13 50% Storage 12 70% Storage 11 Storage (kAF) 10 9 8 7 6 5 4 Jan-15 Jun-15 Oct-15 Feb-15 Mar-15 Apr-15 May-15 Jul-15 Aug-15 Sep-15 Nov-15 Dec-15 35 1/19/2016

Truckee River Basin Reservoirs Reservoir Construction Date Use Storage Volume (AF) Lake Tahoe 1874 / 1913 Floriston Rates 744,600 Independence Pre 1900 / 1939 POSW 3,000 / 17,500 Donner 1928 POSW 9,500 Boca 1938 Rates / FC / CS 40,870 Prosser 1963 TPX / Fish / FC 29,840 Stampede 1969 Fish / FC / CS 226,500 Martis 1971 Flood Control 20,400 36 1/19/2016

Lake Tahoe Facts Maximum Elevation: 6229.10 feet Elevation of Natural Rim: 6223.00 feet Vertical Storage: 6.10 feet Storage Capacity: 744,600 acre feet Total Capacity: 122,160,000 acre feet Historical Max. Elevation: 6231.26 feet (July 1907) Historical Min. Elevation: 6220.26 feet (Nov. 1992) 37 1/19/2016

Lake Tahoe Facts Average Annual Precipitation (Tahoe City): 32.33 inches +/- 3.8 feet (460,000 AF) Average Annual Evaporation: “Normal Year” Release: +/- 9.5 inches (95,000 AF) Tahoe’s annual surface evaporation is enough water to meet the Reno - Sparks area surface water demands for over five years! Surface Area: 85,000 acres in CA + 37,000 acres in NV = 122,000 acres 38 1/19/2016

RiverWare Development Process • Began in 2000 – Joint effort between Reclamation and TROA Implementation Office (Water Master’s Office) • 2009: Shift in Responsibility – TROA Implementation Office in lead role for Ops model – Reclamation support Ops model; lead planning modeling • 2010: Planning Model Development, Water Quality Modeling 39 1/19/2016