Yakima Basin WY 2019OWSA & River Operations Meeting, October 3, 2019

Yakima Airport Weather, Pendleton, National Weather Service

(114 % average, estimated)

NRCS SWE % AVG

USBR North South

1-NOV 0 0 trace

1-DEC 36 44 45

1-JAN 92 94 94

1-FEB 77 71 85

1-MAR 88 78 97

1-APR 75 69 92 (79)

1-MAY 59 62 85 (79)

1-JUN 2 5 49 (51)

1-JUL 0 0 0

Period Temperature Precipitation6-10 day (Oct 7-11) Below Norm Above Norm8-14 day (Oct 9-15) Below Norm Above Norm

Seasonal Outlook (date issued) Oct (Sep 19) Above Normal Above NormalFall (Sep 19) Above Normal Equal Chance Winter (Sep 19) Above Normal Equal ChanceSpring (Sep 19) Above Normal Equal Chance

“ENSO-neutral conditions are present. ENSO-neutral is favored during the Northern Hemisphere fall 2019 (~75% chance), continuing through spring 2020 (55-60% chance).” (12 September 2019) .

Climate Prediction Center

http://www.cpc.ncep.noaa.gov/products/predictions/610day/ http://www.cpc.ncep.noaa.gov/products/predictions/814day/https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdfhttp://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/enso.shtml http://www.nws.noaa.gov/climate/outlook.php?wfo=pdt&site=459465http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/http://www.cpc.ncep.noaa.gov/products/predictions//multi_season/13_seasonal_outlooks/color/churchill.php

Extended Range Forecasting 30-90 Day“La Normal…mode has given us some crazy weather at time, and some

of our most severe storm systems…the North Pac is already very active, so I believe the ensuing Winter will be active too. We might not be wet every day, or have multiple snow events but we will have snow and we will have plenty of rainfall! Temps will ride the Roller coaster going from rather cold to rather mild, shifting with the passage of each system! The key is the location of the Jet, sweet spot, under which falls the heaviest precip. Last year that was over NorCal and Oregon, while Washington, BC and Idaho were short-changed. This year the sweet spot will be over the PacNW, including BC, and that should bring impressive rain and Mtn snows back to the North.” Phil Volker, Sep 27, 2019.

Period Temperature Precipitation______

Oct HIGH: +1.7 TO -2.2 LOW: +0.9 TO -2.5 PREC: 105 TO 132%Nov HIGH: +1.4 TO -2.2 LOW: +1.6 TO -2.2 PREC: 118 TO 130%Dec HIGH: +1.6 TO -2.2 LOW: +1.9 TO -2.4 PREC: 118 TO 144%

very shifty and convoluted and variable

Yakima Subbasin forecastsRunoff, AF and % of Average

Recession estimate at this

point

For the Adopted we used composite except for July when we used

Recession Method

2019 TWSA Runoff forecast and prorationingJune 3 – Sep 30

RO FC ProrationMar 90%Apr 77%May 75%Jun 493 68% 74% (72%)Jul 389 53% 67% (67%)Aug 380 52% 69% (69%) Sep 400 55% 69%15Sep412 56% 72%Actual 415 57%

average 730

Parameter* +/-/= Low Adopted HighJune 3-Sep 30 Natural Flow at Parker est. + 391 412 445

Return Flow Estimate + 230 235 235June 3, Reservoir Content plus conservation used early + 863 863 863

Storage Adjustment for Conservation water released from storage before the start of Prorationing. 11 11 11

TWSA = 1495 1521 1554SEP 30 EST RESERVOIR CONTENT - 76 76 76

EST FLOW OVER SUNNYSIDE DAM - 105 106 1121/3 SVID purchased 0 10 10

TWSA FOR IRRIGATION = 1314 1330 1356NONPRORATABLE ENTITLEMENT Adj - 691 684 684

REMAINING TWSA = 623 645 672PRORATABLE ENTITLEMENT 900 897 897

% RATIO= REMAINING TWSA/PRORATABLE ENTITLEMENT 69% 72% 75%

TITLE 12 FLOW REQUIREMENTS, cfs September 300 300 300Flow available to Title 12, cfs *#* 105 140 142

Non-storeable Portion of added flow, cfs 39 39 39Storable portion of added flow, cfs 66 101 103

September 16 Update, 2019, TWSA ESTIMATE June 3 - September 30

*Values are in 1,000 ac-ft unless otherwise specified.*#* State & YRBWEP Trust, Acquisition, & Conservation additions to Title XII flow range from 0 to 0 cfs.

Parameter "+/-/=" Low Adopted HighOct 1 - Oct 20 Natural Flow at Parker est. + 42 66 170

Return Flow Estimate + 20 20 271st of Month Reservoir Content + 172 172 172

OWSA = 234 258 369YRBWEP TITLE 12 ACQUISITION + 2 2 2

TWSA Subtotal = 236 260 371Oct 20 EST RESERVOIR CONTENT - 73 83 192

FLOW OVER SUNNYSIDE DAM - 17 18 20TWSA FOR IRRIGATION = 147 159 159

NONPRORATABLE ENTITLEMENT - 115 115 115REMAINING TWSA = 32 44 44

PRORATABLE ENTITLEMENT 44 44 44% RATIO= REMAINING

TWSA/PRORATABLE ENTITLEMENT 72% 100% 100%TITLE 12 FLOW REQUIREMENTS October 300 300 300

Flow available to Title 12, cfs *#* 120 120 120Non-storeable Portion of added flow, cfs 9 9 9

Storable portion of added flow, cfs 111 111 111

OCTOBER 1, 2019 OWSA ESTIMATE Oct 1 - Oct 20

Reservoir RefillStorage Max, Date

• The Cle fish flume did not open for fish in 2019. • Cle: 359, June 7• Kee: 120, May 18• Kac: 218, June 17• Bum: 34, May 22• Rim: 165.7, Jul 2• System: 868, June 5 and held until June 7.

Yakima Basin Conservation Water2019

• Conservation water account for 2019.• Bucket started on June 3, when prorationing started.• Storage Control Date was Jun 7.• The proration rate varied from a high of 74% in June to a low of

67% in July before settling at 72% in mid-September.• Bucket calculations are based on a proration rate of 72% for the

entire period June 3 – September 30.• Storable conservation water total is 21,777 AF, Jun3-Sep30.• A pulse flow used 11,340AF, May 25-29.

• 10,437 AF remained in the conservation account on Sep 30.• 3,292 AF saved in October.• 13,729 AF Total Saved

Yakima Basin Minimum Flows

• El Nino neutral is expected in 2020.• Nov 1, carry-over will be low. (125 KAF, ranging from 76 to 250 KAF). • Nov-Dec precip. Will be used.• Targets will start at: Kee-80, Kac-30, Easw-190, Cle-180, Bum-130, Rim-50,

Ticw-75.

River Operations Summary• El Nino neutral continue in WY2020.• Reservoir Storage is 172 KAF, 57% of avg and 16% full. • Precip in September was 152%, wet. • Jun 3 – Sep 30 Prorationing settled at 72%.• Title XII flow is 300 cfs plus up to 120 cfs.• Parker target set to 309 cfs October (w/o storable water).• Prosser target 320 cfs in October(w/o storable water).