Lahontan Basin Area Office Water Supply Outlook March 2019 - PowerPoint PPT Presentation

Lahontan Basin Area Office Water Supply Outlook March 2019 Presented by: Dan Lahde

Topics • Newlands Project Credit Water • Water Year 2019 Outlook • NRCS/RFC Forecasted Data • Current/Projected Reservoir Operations 2

Truckee and Carson River Basins and the Newlands Project WINNEMUCCA Pyramid Lake LAKE (dry) Indian Reservation PYRAMID MARBLE BLUFF LAKE Stillwater Nixon NWR Derby Fernley Dam TRUCKEE RIVER STAMPEDE TRUCKEE Fallon INDEPENDENCE CANAL Fallon Indian Reno/Sparks Newlands Reservation BOCA Project LAHONTAN PROSSER MARTIS DONNER Carson CARSON CARSON City LAKE RIVER Tahoe City LAKE TAHOE 3

Newlands Project Credit Water (NPCW) • NPCW establishment is provided for by the Truckee River Operating Agreement (TROA) (TROA §7.H) • Goal of NPCW under TROA: “…make maximum use of Carson River water for the Newlands Project and to minimize diversions of Truckee River water through the Truckee Canal…” (TROA §7.H) • “NPCW established pursuant to TROA 7.H.1 shall be managed by the United States…” 4

NPCW Establishment NPCW Can be Established by: • Exchange volume that would have been diverted at Derby with an equal amount of Fish Credit Water (§7.H.2(a)) • Floriston Rate Holdback - Retaining in storage an amount of Floriston Rate Water (§7.H.2(b)(1)) • Above Floriston Rate Holdback - Retaining in storage Truckee River flow in excess of Floriston Rates (§7.H.2(b)(2)) 5

NPCW Management 6

2018-2019 NPCW Operations 7

WY 2019 Outlook 8

Current WY Precipitation To Date 9

Current Snowpack 10

Historical & Forecasted Apr-Jul Runoff by Basin RFC Mar 10 Forecast 11

Historical & Forecasted A-J Runoff - Truckee RFC Mar 10 Forecast 12

Historical & Forecasted A-J Runoff - Carson RFC Mar 10 Forecast 13

WY 2019 Mar 10 Farad AJ Vol Carson AJ Vol Tahoe Gate Closed (KAF) (KAF) Rise (ft.) RFC Forecast - 30% (W) 563 330 2.6 50% (M) 487 275 2.1 Hydrograph 70% (D) 389 196 1.6 14

Average & Forecasted Farad Flow 15

Forecasted Ft. Churchill Inflows = 618 cfs Lahontan Inflows Lahontan Reservoir = 194,6100 AF 16

Average & Forecasted Ft. Churchill Flow 17

Current Reservoir Storage 18

Stampede Reservoir Storage Forecast 19

Lake Tahoe Storage Forecast 20

Lahontan Reservoir Storage Forecast 21

Boca Reservoir Storage Forecast 22

Lahontan Reservoir Storage Forecast - MRM 47 out of 59 Traces (79%) store on the boards 20 of 59 Traces (33%) stores to the top of the boards 23

Lahontan Forecasted Total Outflow (cfs) - MRM 26 of 59 (43%) Traces Require Precautionary Drawdown 24

CKM6 Current Lahontan Operations • The 30% and 50% RFC forecast exceedance runs show Lahontan Reservoir storing on the flashboards in 2019. • MRM Riverware run forecasts that 33% of traces will fill Lahontan and 43% of traces show a precautionary drawdown. • Based on the forecast, no additional NPCW will be established or released in 2019. 25

Slide 25 CKM6 Need to edit Clancey, Katherine Marie, 3/8/2019

End! End! Comments or Questions? Comments or Questions? 26