Water Year 2012: Review of Water Supply Forecasts in the Colorado River Basin CRFS November 14, 2012

Green River Basin Upper Green Duchesne Yampa Dry everywhere Extreme dry conditions in Yampa, Duchesne

Upper Green: Basin Conditions Precipitation% of Average October120 November115 December48 January130 February112 March48 April64 May43 June5 July104 Water Year71 103% 98% 83%

508 KAF 70% ESPSWSNRCSCOOR % Jan Feb Mar April May Jun FONTENELLE RESERVOIR 2012 MAE Jan : 42 KAF Feb: 177 KAF Mar: 222 KAF Apr: 157 KAF May: 30 KAF June: 20 KAF

570 KAF 58% ESPSWSNRCSCOOR % Jan Feb Mar April May Jun FLAMING GORGE 2012 MAE Jan : 190 KAF Feb: 310 KAF Mar: 375 KAF Apr: 240 KAF May: 64 KAF June: 11 KAF

FLAMING GORGE LOCAL: (Flaming Gorge Inflow-Fontenelle Inflow) Observed Local 62 KAF/24% 4 th Lowest ObsAverage% April % May % June % July % ESP local too high….

Yampa: Basin Conditions Precipitation 2012 % of Average 2002 % of Average October96110 November9487 December2865 January6256 February12651 March3184 April5557 May2419 June318 July11168 Water Year % 80% 52%

337 KAF 36% Yampa nr Maybell ESPSWSNRCSCOOR % Jan Feb Mar April May Jun #1 1977: 261 KAF #2 2002: 269 KAF #3 1934: 278 KAF #4 2012: 337 KAF 2012 MAE Jan : 363 KAF Feb: 298 KAF Mar: 378 KAF Apr: 163 KAF May: 61 KAF June: 31 KAF

April-July Volume (KAF)Historical Volume (KAF)% Average2012 L-HMin (KAF)Min Year Yampa abv Stagecoach3.5215%2/ Yampa at Steamboat Springs10540%4/ Elk near Milner17354%3/ Elkhead Creek abv Long Gulch20.328%2/ Yampa at Maybell33736%4/ Little Snake nr Slater7347%4/ Little Snake nr Savery9026%1/ Little Snake nr Lily11132%4/ White near Meeker11139%4/ White near Watson9835%4/ All April-July Volumes are in bottom five of historical records!

Duchesne: Basin Conditions 67 %53% 72% Precipitation% of Average October146 November84 December39 January72 February92 March62 April60 May16 June2 July174 Water Year76

31 KAF 42% 31KAF 47% Neola and Lake Fork -Over forecast issues (~20-30% over forecast in May) -Same pattern at all points on the south slope of the Uintas 2012 MAE Jan : 25 KAF Feb: 21 KAF Mar: 21 KAF Apr: 19 KAF May: 13 KAF June: 5 KAF

Upper Colorado Basin Mainstem Gunnison Dolores Extreme dry

Upper Colorado Mainstem Basin Conditions

April Forecast 900 KAF 38% Colorado - Cameo ESPSWS raw pref rtd NRCS raw pref rtd COOR %Jan p p % Feb p p % Mar p p % April p p % May p p % Jun p p 93039%

Upper Colorado 2012 Volumes April - July 2012Historical 2011 H-L Ranking Volume (kaf)% avg 2012 L-H RankingMin (kaf)Year Lake Granby11652%3 / Willow Creek Res2043%6 / Fraser - Winter Park8.2442%2 / Williams Fork Res3941%2 / Dillon Res6037%2 / Green Mountain Res11241%2 / Wolford Mountain Res2139%3 / Colorado - Kremmling35141%2 / Eagle - Gypsum13340%3 / Colorado - Dotsero55039%2 / Ruedi Res5641%3 / Roaring Fork - Glenwood26238%3 / Colorado -Glenwood85140%3 / Colorado - Cameo90038%3 / Platuea Ck - Cameo3024%3 / Colorado - Cisco150334%2 / Lake Powell206329%3 /

Gunnison Basin Conditions

2012: 206 KAF (31% of average) ESPSWS (route) NRCS Statics COOR % Jan Feb Mar April May Jun

2012: 120 KAF (41% of average) ESPSWS (Route) NRCS Statics COOR % Jan Feb Mar April May Jun

San Juan Basin Dry, but not quite as extreme as further north

San Juan Basin Conditions

2012: 230 KAF (55 % of average) ESPSWSNRCS Statics COOR % Jan Feb Mar April May Jun

Forecast Evolution Plot 2012: 107 KAF (55 % of average)

Lake Powell

Lake Powell Basin Conditions

% % % 2063 KAF 29% April Forecast Lake Powell ESPSWS raw pref rtd NRCS raw pref rtd COOR %Jan p p % Feb p p % Mar p p % April p p % May p p % Jun p %

2063 KAF / 29% (#3 / 49) 1128 KAF / 38% (#4 / 108) 375 KAF / 34% (#6 / 89) 1503 KAF / 34% (#2 / 32) 2002 Obs (kaf) % AvgRank (kaf) Green – Green River, UT81828%3310 Colorado – Cisco105724%1446 San Juan – Bluff00%1375 Lake Powell96413%11099

Lower Colorado Basin Virgin: Snowpack far behind average by mid January Snowpack melted out very early (order of weeks) April-June warmer than average and accelerated melt May and June very dry (finally saw precip in July) Salt-Verde: Generally dry for an extended period, particularly in Verde La Nina conditions – continued from last year Dry soil conditions entering the season Early season snowpack fizzled Weighted ESP was better guidance Phoenix dust storm Virgin

WY12 Official Forecasts Virgin (VIRU1) AMJJ Observed = 26.5 KAF (46% AVG) AMJJ Average = 58.1 KAF VIRU1Official Fcst (COORD)Error Jan Feb Mar Apr May Jun SUMMARY: Early months: overforecast (especially January). As season progressed: Precip dried out; fcsts dropped. Fcsts issued in Apr, May, June: were closest to the volume that was eventually observed. Least Erroneous Official WY12 Fcst : May

SALT – ROOSEVELT: 2012 CBRFC-NRCS COORDINATED FORECASTS Progressive Forecast Period (Forecast Issue Date through May) Volume in kAF

VERDE-HORSHOE: 2011 CBRFC-NRCS COORDINATED FORECASTS Progressive Forecast Period (Forecast Issue Date through May) Volume in kAF