Navajo Unit Operations

Coordination Meeting

January 19, 2021 1:00 PM

Microsoft Teams Virtual Meeting
• Review of operations to date WY 2021

• Current reservoir status

• Current soil and snowpack conditions

• WY 2021 weather and flow forecasts

• WY 2021 proposed operations

• Navajo Dam maintenance activities

• Reports from other entities

Agenda


Reclamation Hydro Data 

https://www.usbr.gov/uc/water/hydrodata/reservoir_data/site_map.html
Reclamation Teacup Diagrams

https://www.usbr.gov/uc/water/basin/index.html
Reclamation HydroData Basin Status

https://www.usbr.gov/uc/water/

hydrodata/status_maps/


Reclamation Snow to Flow Charts

https://www.usbr.gov/uc/water/hydrodata/stf/
Weather Outlook

January 2021

Aldis Strautins

National Weather Service

Grand Junction, CO

http://www.weather.gov/gjt
Weather Outlook

January 2021

• Since the first of the water year temperatures over southeastern 

Utah were cooler than normal and over southwestern Colorado 

warmer than normal. For Precipitation well below normal over 

the headwaters since the first of the year. 

• So far for the beginning of January colder than normal with 

precipitation well below normal. 

• The latest storm in late December brought some brief relief to 

southwestern Colorado but the first half of January has been dry.

• Exceptional drought remains entrenched over the head waters 

and Four Corners region. 

Discussion / Outline
Weather Outlook

January 2021

• ENSO-La Nina conditions are present and are expected to 

continue this winter and then transition toward neutral during 

the Spring. 

• A more progressive pattern is indicated for the second half of 

January which would allow more storms and increased 

precipitation chances.

• Spring into early summer higher chances of below normal 

precipitation. Higher chances of above normal temperatures 

• Drought is predicted to remain.

Discussion / Outline
The Past

January 2021

Water Year 2021

Temperature

Departure from normal

Precipitation

% of normal
The Past

January 2021

From January 1, 2021

Temperature

Departure from normal

Precipitation

% of normal
The Past

January 2021

From January 1, 2020 through December 31, 2020

Temperature

Departure from normal

Precipitation

% of normal
SNOTEL

January 2021

SNOTEL - Percent of Normal - Colorado

Water Year 2021

SWE Precipitation
Snow

January 2021

SNOTEL Snow Water Equivalent – NRCS

Southwestern Colorado
Snow

January 2021

SNOTEL Snow Water Equivalent – NRCS

Southwestern Colorado

SWE Pct of Normal

As of Jan 14

Dolores Basin: 65%

San Juan Basin: 82%

Animas Basin: 66%

Precip Pct of Normal

As of Jan 14

Dolores Basin: 53%

San Juan Basin: 66%

Animas Basin: 48%
Drought

January 2021

January 12, 2021 January 7, 2020

Drought – Monitor
Drought

January 2021

January 12, 2021 October 6, 2020

Drought – Monitor
Season La Niña Neutral El Niño

DJF 2021 100% 0% 0%

JFM 2021 96% 4% 0%

FMA 2021 78% 22% 0%

MAM 2021 57% 43% 0%

AMJ 2021 43% 55% 2%

MJJ 2021 35% 58% 7%

JJA 2021 37% 52% 11%

JAS 2021 42% 45% 13%

ASO 2021 44% 41% 14%

ENSO

January 2021

CPC/IRI Early-Month Consensus ENSO Forecast 

Probabilities

(using NWS CPC classification system)

ENSO – Outlook

La Nina remaining through winter
Weather Outlook

January 2021

Temperature Precipitation

Jan 21-25 – Outlook

updated Jan 15
Weather Outlook

January 2021

Temperature Precipitation

Jan 23-29 – Outlook

updated Jan 15
Weather Outlook

January 2021

Temperature Precipitation

Feb/Mar/Apr – Outlook 
Weather Outlook

January 2021

Temperature Precipitation

Apr/May/Jun – Outlook
Weather Outlook

January 2021

Seasonal

Drought– Outlook
CPC Seasonal Outlook (updated Jan 18, 2021)

La Niña is expected to continue through the Northern Hemisphere winter 2020-21 (~95% chance 

during January-March), with a potential transition to ENSO-neutral during the spring 2021 (55% 

chance during April-June).
CPC Seasonal Outlook (from 2018)

Weak La Niña
CPC Seasonal Outlook (from 2019)

Weak El Niño
Navajo Reservoir/San Juan Basin

Water Supply Outlook

January 2021

Ashley Nielson

Senior Hydrologist

Colorado Basin River Forecast Center

National Weather Service/NOAA
April-October 2020 Observed Monthly Precipitation Summary

• Anomalous ridging dominated the weather pattern from the late spring 

into the fall across the region.

• Very little monsoon activity; one event in July

• Record to near record dry Apr-Oct 

April May June July

August September October

9%

16%

21%

28%

55%

110%

99%

105%

17%

17%

65%

41%

50%

16%
April-October 2020 Observed SNOTEL Precipitation Statistics (NRCS)

• Near/record dry Apr-Oct precipitation across the region

• SNOTELS have a 35-40 year period of record.
Percent of normal 

soil moisture

San Juan River Basin

Soil moisture conditions entering the winter season

Fall 2019

Soil moisture conditions are below normal and generally in the bottom 3 of the 1981-2020 40-year period. 

Conditions are similar to last year in the eastern headwaters but worse over the rest of the basin. 

Fall Model Soil Moisture Conditions: 2019 vs. 2020

Fall 2020
A look back at streamflow 

JUL 2019

OCT 2019

Monsoon

Season

JUL 2020

OCT 2020

Monsoon

Season

Lowest Flows 

on Record 

In the San Juan, monsoon 

precipitation is needed to help 

recharge groundwater and keep 

baseflows elevated through the 

summer and fall. There has not 

been significant recharge since 

2019 runoff. 

Flows have been record or near 

record low since late summer on 

the Animas. This is another 

example of the low antecedent 

conditions and an indirect indicator 

of the large soil moisture deficit 

present.
Snow Conditions: CBRFC Model and SNOTEL (NRCS)

Snow conditions are below normal for mid January. 

The high elevation areas of the eastern headwaters 

above Navajo have the best snow conditions, between 

70-85% of normal, due to storms in November and 

late December. 

CBRFC Model Snow: January 17

78%

64%

Composite of NRCS 

SNOTEL site obs
January 1st Water Supply Forecasts: San Juan River Basin

April-July Forecasts

Volume in 1000’s acre-feet / Percent of 1981-2010 average

San Juan-Bluff

580 / 53%

Vallecito

110 / 57%

AnimasDurango

240 / 58%

Navajo

450 / 61%

San JuanFarmington

610 / 55%

San JuanPagosa

160 / 74%

Early season forecasts range from 45-80% normal with a median forecast of 55% in 

the San Juan river basin. 

Main forecast drivers:

• Dry antecedent soil moisture conditions

• Below normal snow conditions
Forecast Progression: Navajo Reservoir Inflow 

Wet in the future (590 KAF / 80%)

January 18 Forecast Guidance: 350 KAF/ 48%

Dry in the future (255 KAF / 35%)

Average Weather = Median of historical climatology

Historical Climatology = 1981-2015 historical temperature and precipitation

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

Blue line: Daily Raw Model Guidance 50% exceedance

Pink line: Official forecast 90%, 70%, 50%, 30%, 10% exceedance

Green solid: 1981-2010 average April-July volume

Green dotted: 1981-2010 median April-July volume

Brown dotted: Average observed

Average weather in the future

Future Weather (precipitation/temperature) = Historical Climatology Future Weather = 7 day Precipitation Forecast + Historical Climatology

Upcoming storms+ wet in the future (720 KAF / 98%)

January 18 Forecast Guidance: 430 KAF / 59%

Upcoming storms + dry in the future (325 KAF / 44%)

Upcoming storms + average weather

• The forecast has decreased since Jan 1 due to dry conditions.

• The forecast will continue to decrease if the upcoming storms do not 

verify.

• The forecast will likely stay similar to Jan 1 if the upcoming storms do 

verify. 

Navajo Inflow Forecast Plot Link
Early Season Forecast Uncertainty

January 1st Forecast:

What we know:

• ~40% of snowpack accumulation

• Fall soil moisture conditions

What we DON’T know:

• Jan-May weather (4 months)

• ~60% of snowpack accumulation

Average January Forecast Error: ~200 KAF

April 1st Forecast:

What we KNOW:

• ~98% of snowpack accumulation

• Dec-March weather

What we don’t know:

• April-May weather (2 months)

• Snowmelt pattern

January 1

April 1

Average April Forecast Error: ~100 KAF YEAR

JAN 1 FCST 

(KAF)

FCST % 

AVG

OBSERVED 

(KAF)

OBSERVED % 

AVG

2018 350 48% 154 21%

2019 370 50% 1163 158%

2013 440 60% 267 36%

2015 450 61% 619 84%

2021 450 61% ? ?

Historical Years with similar January 1 Forecasts
Upcoming Weather

January 18-25 Precipitation Outlook

8-14 Day Outlook (January 25-31)

Temperature Outlook

Precipitation Outlook
Summary

• Near/record dry April-December 2020 period across the San Juan River Basin

• Near/record low antecedent soil moisture conditions entering water year 2021 snow accumulation & runoff season

• Two consecutive years of poor Monsoon 

• Limited groundwater recharge since 2019 runoff

• Slow start to the snow season

• Current snowpack (SWE) conditions are below to well below normal across the majority of the basin

• Early January is a little less than halfway (~40-50%) through the snow accumulation season

• January water supply forecasts (% of normal):

• Range between 45-85% of average

• Best conditions are located in the eastern headwaters and deteriorate moving west towards the Animas.

• Trend in forecasts will depend on how storms over the next week materialize

• Weather pattern over the next 7-10 days looks more favorable for the San Juans

• Decent chances for widespread precipitation

• Could see more low/mid elevation snow than high elevation snow for first storm (Monday-Tuesday)

• Closed lows are notoriously difficult to forecast.

• Uncertainty remains for weekend and early next week storms

• Given the dry conditions, an above normal snowpack or a wet spring will be needed to see near average water supply volumes.

• Dry soils will most likely impact runoff efficiency
Contact Info/COVID-19 Updates

COVID-19 Staffing

• 1 person in the office per day

• Additional personnel in the office during:

• Water Supply Forecast Updates (1st week of Month)

• Hydrologic events (runoff/flooding)

• Maximum telework for the rest of the staff

• No changes in the foreseeable future

Contact Information

• Operational Hydrologist: in office

• 801-524-4004

• cbrfc.operations@noaa.gov

• Ashley Nielson - San Juan River Forecaster

• ashley.nielson@noaa.gov

• 801-524-5130 x333 Forwards to my cell phone

CBRFC Webpage

https://www.cbrfc.noaa.gov/

CBRFC Water Supply Presentations

https://www.cbrfc.noaa.gov/present/present.php
CBRFC Water Supply Forecasts

https://www.cbrfc.noaa.gov/

Water Supply 

Forecasts 

(April-July)

As of Jan, 2021
Water Supply 

Forecasts (April-July)

Navajo: 450 kaf (61% avg)

Vallecito: 110 kaf (57% avg)

Lemon: 31 kaf (57% avg)

Animas: 240 kaf (56% avg)

McPhee: 170 kaf (58% avg)

Powell: 3,800 kaf (53% avg) As of Jan, 2021
San Juan River Recovery Implementation Program Modified Decision 

Tree (2018)

PRELIMINARY AVAILABLE WATER CALCULATION FOR WY 2021

CBRFC Forecast Date: 1/11/2021

Forecast

Available 

Water over 

6050 (kaf)

Available Days 

at Peak (need 

min of 21 for 

SPR)

Proposed 

Release

Proposed 

Release 

Volume (kaf)

Available for Adaptive 

Management 

(Remaining water 

>6063 ft) (kaf)

Sept 30 Pool 

Elevation (ft) 

with proposed 

release

MIN -383 0 none 0 0 6011

MOST -76 0 none 0 0 6043

Current Forecast

MAX 146 3 none 0 0 6062
CBRFC Ensemble Streamflow Prediction 

(ESP) Traces




What does it mean?

Based on current storage levels and the ESP trace forecasts, 

• Less than 5% chance of SJRIP-prescribed spring peak release of at least 21 days at 

5,000 cfs. 

• 30% chance peak pool elevation will be 6050 ft or higher.

• 10% chance peak pool elevation will be 6060 ft or higher.

• 25% chance the Sept 30th pool elevation will be 6050 ft or higher.

• 5% chance the Sept 30th pool elevation will be 6060 ft or higher.

• Flows at Four Corners are unlikely to meet SJRIP Flow Targets under these 

forecasts.

• No runs result in a shortage for WY 2021, however, 6% chance of shortage in WY 

2022. 
• Snowpack is well-below average (65% above Navajo) and dry soils coming into the season further 

reduce the spring inflow forecasts.

• CPC outlook is showing a chance for drier than average conditions through the spring and a high 

chance for warmer than average.

• The April-July runoff most probable forecast for Navajo is 450kaf (61% of average).

• Based on current conditions (snowpack and reservoirs), and the range of forecast possibilities 

provided by CBRFC, a spring peak release in 2020 is very unlikely. BUT remember we have been in 

this situation in prior years (2019 for example). By spring there was enough for a large release. So 

do not count it out just yet!

• Expect low releases throughout the winter (300-500 cfs) as minimum releases to meet the target 

baseflows will be made.

• Currently no model runs result in a shortage for WY 2021.

Summary Next mtg April 20th – Virtual Format Likely
Reclamation Contacts:

Marc Miller – Water Management Group Chief

970-385-6541 mbmiller@usbr.gov

Susan Novak Behery – Hydrologic Engineer

970-385-6560 sbehery@usbr.gov

To be added to Navajo Dam notices email list, send an email to 

westcoloareaoffice@usbr.gov 

Useful Links

Reclamation: www.usbr.gov/uc

USGS: water.usgs.gov/nwis

CBRFC: cbrfc.noaa.gov