Aspinall Operations Meet

January 19, 2023
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Introductions and Purpose of Meeting

Gunnison Basin Water Supply Outlook – Ashley NiAspinall Unit Operations – Erik Knight (ReclamatiSpecial Flow Requests and Discussion Reports of Agencies and Organizations – AllConclusions (Next meeting date – April 20th

)
Aspinall Operations Meeting

Water Supply Outlook

January 2023

Ashley Nielson

Senior Hydrologist

Colorado Basin River Forecast Center

National Weather Service/NOAA
Water Year 2023: Upper Colorado River Observed Precipitati

October November 

Above Blue Mesa Reservoir: 95%Gunnison River Basin: 100%

Above Blue Mesa Reservoir: 75%Gunnison River Basin: 75%

December

Above BluGunnison 

Observed precipitation is averaged by major contributing area within a basin. 
Water Year 2023: Upper Colorado River Temperature Depart

MAX 

October November December

MIN
Water Year 2023: January Precipitation and Temperature

January 1-18 

Above Blue Mesa Reservoir: 190%Gunnison River Basin: 220%
Water Year 2023: Water Year Precipitation to Date

Observed precipitation is averaged by CBRFC basin defined elevation zones of major contributing areas.
Drought Conditions: U.S Drought Monitor
Upper Colorado River: Fall 2022 Model Soil Moisture Conditions

The map shows the model soil moisture conditioin CBRFC’s hydrologic model. This zone represeterm (weeks-to-years streamflow).Modeled lower zone soil water content is a result conditions including but not limited to:

-previous year(s) runoff-summer/fall precipitation

Soil moisture content is adjusted every fall during irrigation season has ended and before winter. Ffollowing data to make adjustments:

-Early November streamflow observations (-Reservoir inflows-July-October precipitation

-Past season(s) runoff conditions

CBRFC model soil moisture conditions are across many of the major runoff producing 
Fall 2021 Fall 2022 % Change: 20

Fall Modeled Soil Moisture Conditions

Soil Moisture Impacts:

1. Water Supply Forecasts

● Below average conditions= lo● Above average conditions= h

2. Spring Runoff Efficiency

● Soil moisture deficit must be ● Degree of impact is uncertain ● Timing/magnitude of runoff is 

■ Spring Weather (precipit■ Snow Conditions■ Soil Moisture Conditions

Gunnison River Basin: Fall 2022 Model Soil Moisture Conditions

Soil moisture conditions are near to below normal over the Gunnison River Basin. Soil moisture deficits still exist.Conditions are similar to last fall with the exception of a few headwater basins that have improved conditions and some southern basins that have worse conditions than last year. 

Model soil moisture is averaged by major contributing area within a basin. 
Snow Conditions: SNOTELS and CBRFC Model Snow Water Eq

January 18, 2023

Model snow includes areas above and below SNOTEL sites.

● SNOTEL locations range from ~9,000-11,500’ ● Some modeled basins extend to over 14,000’
April-July Forecasts

Volume in 1000’s acre-feet / Percent of 1991-2020 average

January 2023 Water Supply Forecasts: Gunnison River Basin 

Forecast Range is 90-110% of average

Mid-January Model Guidance Forecast Range: 90-155% of ave

April-July Volumes (ka

Gunnison

Grand Junction

1300 / 98%

Ridgway

90 / 98%

Blue Mesa

605 / 95%

East 

Almont

166 / 94%

Paonia

85 / 105%

Tomichi 

Creek

60 / 90%
Blue shading: Daily Raw Model Guidance 90% - 10% exceedance range

Blue line: Daily Raw Model Guidance 50% exceedancePink line: Official forecast 90%, 70%, 50%, 30%, 10% exceedanceGreen solid: 1991-2020 average April-July volumeGreen dotted: 1991-2020 median April-July volumeBrown dotted: Average observed Blue Mesa Inflow Forecast Plot Link

Forecast Evolution: Blue Reservoir Inflow: 

90% chance of exceeding 460 KAF / 72% avg

Mid-Month Forecasts:

50% chance of exceeding 650 KAF / 102% avg50% chance of NOT exceeding 650 KAF / 102% avg

Jan 1 Forecast: 605 KAF / 95%

10% chance of exceeding 985 KAF / 155% avg

NOTE: 20% chance that the April-July runoff will fall outside of the forecast range.

Jan 2022 Fcst: 650 K2022 Runoff : 431 K
High pressure will temporari

area through Thursday followstorm system Friday-SaturdAn active weather pattern is continue into next week with possible early next week. Thdisagreement among weaththe exact track of the storm, generally good that another move through the region nex

Days 1-7

Future Weather: January 18-25 Forecast Precipitation
Future Weather: January 26 -February 1 
Climate Prediction Center: Seasonal (JFM) Outlook
Summary

• Soil moisture

• Conditions are below to near normal.• Soil moisture deficits still exist; must be overcome before runoff can occur.• Impact on runoff uncertain and will depend on spring weather and snow conditions.

• Snow

• Snow conditions have improved since early January due to a favorable weather pattern.• Above median conditions as of mid-January• Mid-January is a little less than halfway (~40-50%) through the snow accumulation season

■ Still early in the snow season

• January Water Supply Forecasts

• Forecasts range from:

■ Early-January: 90-110% of average■ Mid-January: 90-155% of average

• Forecast guidance has increased since early January.• Expect an increase in February forecasts.

• Upcoming Weather

• Active weather pattern looks to continue through the end of the month.• Shift in pattern to colder storm systems with less moisture. 
Contact Info

Contact Information

• Ashley Nielson - Gunnison River Forecaster

• ashley.nielson@noaa.gov• 801-524-5130 x333 

• Operational Hydrologist: in office

• 801-524-4004• cbrfc.operations@noaa.gov

CBRFC We

https://www.cbrf

CBRFC Water Supp

https://www.cbrfc.noaa.go

Contact Info:
Introductions and Purpose of Meeting

Gunnison Basin Water Supply Outlook – Ashley NiAspinall Unit Operations – Erik Knight (ReclamatiSpecial Flow Requests and Discussion Reports of Agencies and Organizations – AllConclusions (Next meeting date – April 20th

)
RESERVOIR AND RIVER ST

Blue Mesa Reservoir ended 2022 at an elevation of 7446.5 ft, 4

the winter target elevation of 7490 ft

Blue Mesa Reservoir content is currently at 293,000 acre

‐feet a

of 7447 feet.Crystal Dam is releasing 350 cfs and flows in the Gunnison Rive

Black Canyon are 350 cfs

Releases/river flows will likely remain unchanged until the star

Flows in the lower Gunnison River at the Whitewater gage are 

be above the baseflow target of 750 cfs



SNOW CONDITIONS

Snow accumulation in the Upper Gunnison Basin:

Oct

= 90% of average

Nov

= 67% of average

Dec

= 115% of average

Jan

= 200% of average (so far)

January snow accumulation has already exceeded normal accu

the entire month
Jan SWE

To date

Avg Jan SWE

To Date

Avg T

Jan S

Butte 4.9” 1.8” 2.9Schofield 9.7” 3.8” 6.7

Porphyry 3.2” 1.8” 3.4

Slumgullion 2.4” 1.2” 2.4Park Cone 2.9” 1.3” 2.1

Independence 2.7” 1.7” 3.0

January Snowpack Conditions




SPRING RUNOFF 

FORECASTS AND TARGE

Early season runoff forecasts for major rivers in the Gunnison Ba

90

‐105% of average range

The Jan 15th runoff forecast for Blue Mesa Reservoir puts 2023 in

Dry hydrologic category

The ROD targets in the Average Dry category call for

a peak flow 

Whitewater. This is the half bankfull flow and the duration at thi

10 days.

The Black Canyon water right peak flow target is ~3720 cfs.

Shoulder flow targets in the Black Canyon are 420 cfs for May

1 – 


Spring Peak & Duration Targets

Based on Hydrologic Year Type

Most Prob

605,000

Max Prob

985,000

Min Prob

460,000

4570 cfs * .815 = 3723 cfs

Jan 1 Forecast

605 KAF

Drought Recovery Provision 1. Avg Dry/Mod Dry/Dry year follo

2. BM content < 550 Kaf on Dec 31
Baseflow Targets


Projected Operations WY 

• Drought Response Operations Plan (DROA) – releases from In

Lake Powell

• No decisions have been made yet regarding releases

• Meetings and discussions are ongoing regarding any potentia

releases, accounting and recovery

• Will have more information by the April meeting
Questions...??
Introductions and Purpose of Meeting

Gunnison Basin Water Supply Outlook – Ashley NiAspinall Unit Operations – Erik Knight (ReclamatiSpecial Flow Requests and Discussion Reports of Agencies and Organizations – AllConclusions (Next meeting date – April 20th

)