Navajo Unit Operations

Coordination Spring Meeting SlidesApril 21, 2020Reclamation Western Colorado Area Office
MEETING NOTICE

In response to the recommendations from the CDC, local authorities

Department of Interior guidance, the spring coordination meeting fo

of the Navajo Unit, scheduled for Tuesday, April 21st, at 1:00 pm, was 

These slides are being provided in lieu of the meeting, along with an 

summary document. Please contact Susan Behery (sbehery@usbr.go

6560) for any questions or comments you might have.

The next coordination meeting for the Navajo Unit is being schedule

A notice will be sent out when the date is finalized.
• Despite near-average snowpack, dry soils persist and are expecte

effect on runoff efficiency. Runoff forecasts throughout the basin average for this reason.

• Navajo Reservoir is expected to peak between 6060 and 6065 ft. 

are planned for this spring. Releases from Navajo Reservoir are eremain at or near the current level through spring runoff. 

• After runoff ends, Navajo releases will likely increase to accommo

season while maintaining the recommended target baseflow ranhabitat reach. Releases are expected to vary between 500 and 1,0

• Other Reclamation projects in the San Juan River Basin are not p

under the most recent runoff forecasts.

Summary


Current Reservoir Status
Current Snowpack Status

WY 2019 (last year) and WY 2011 shown similar SWE Peak) for comparison.
Weather Outlook

April 2020

Aldis Strautins

National Weather Service

Grand Junction, CO

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

April 2020

• Since the first of the year over southeastern Utah cool

normal and over southwestern Colorado warmer than 

For Precipitation well below normal over the headwat

the first of the year.

• So far for the beginning of April warmer than normal w

precipitation well below normal since the first of the m

• The latest storm last week and into the weekend broug

relief to northern Colorado but very little to southwest

Colorado. The melt did slow slightly but there were no 

in snowpack for the major southwestern river basins.

Discussion / Outline
Weather Outlook

April 2020

• Moderate drought remains entrenched over the head 

severe drought over the lower elevations of southeast

and southwestern Colorado.

• ENSO‐neutral conditions are present and are expected 

continue into the fall of 2020.

• Late spring into summer equal chance of either above

normal precipitation. Higher chances of above normal

temperatures

• Drought is predicted to remain.

Discussion / Outline
The Past

April 2020

Water Year 2020

Temperature

Departure from normal

Precipitati

% of norm
The Past

April 2020

From January 1, 2020

Temperature

Departure from normal

Precipitati

% of norm
The Past

April 2020

From April 1, 2020

Temperature

Departure from normal

Precipitati

% of norm
Snotel

April 2020

SNOTEL ‐ Percent of Normal ‐ Colorad

Water Year 2020

SWE Precipitation
Snotel

April 2020

SNOTEL ‐ Percent of Normal

Water Year 2020

SWE Precipitation
Snow

April 2020

SNOTEL Snow Water Equivalent – NR

Southwestern Colorado
Snow

April 2020

SNOTEL Snow Water Equivalent – NR

Southwestern Colorado

SWE Pct of Normal

As of Apr 20

Dolores Basin: 91%

San Juan Basin: 84%

Animas Basin: 94%
Drought

April 2020

January 14, 2020 April 14, 20

Drought – Monitor
Drought

April 2020

April 14, 2020 October 1, 2

Drought – Monitor
Season La Niña Neutral El Niño

MAM 2020 0% 59% 41%AMJ 2020 4% 66% 30%MJJ 2020 11% 64% 25%

JJA 2020 20% 58% 22%

JAS 2020 26% 52% 22%

ASO 2020 30% 48% 22%SON 2020 34% 45% 21%OND 2020 37% 41% 22%NDJ 2020 38% 39% 23%

ENSO

April 2020

CPC/IRI Early‐Month Consensus ENSO Forecast

Probabilities

(using NWS CPC classification system)

ENSO – Out

ENSO‐ Neutral remaining Neutral until w
Weather Outlook

April 2020

Temperature Precipitati

May – Outlook

updated Apr 16
Weather Outlook

April 2020

Temperature Precipitati

May/Jun/Jul – Outlook

updated Apr 16
Weather Outlook

April 2020

Temperature Precipitati

Jun/Jul/Aug – Outlook

updated Apr 16
Weather Outlook

April 2020

Seasonal

Drought– Outlook
Navajo Reservoir/San Juan Basin

Water Supply Outlook

April 2020

Ashley Nielson

Senior Hydrologist

Colorado Basin River Forecast Center

National Weather Service/NOAA
April 1st Water Supply Forecasts: San Juan Basin

April-July Forecasts

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

San Juan-Bluff

805 / 73%

Vallecito

160 / 82%

Animas-Durango

350 / 84%

Navajo

550 / 75%

San Juan- Farmington

820 / 75%

San JuanPagosa

170 / 79%

San Juan-Bluff

680 / 62%

Vallecito

151 / 78%

Animas-Durango

310 / 75%

Navajo

440 / 60%

San Juan

Farmington

675 / 61%
Water Supply Forecast Evolution: Navajo Inflow Forecast

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

Orange shading: Observed volume to date

Brown dotted: Average observed

Wet in the future (78%)

April 15 Forecast: 380 KAF/52%

Dry in the future (36)%

Observed: 36KAF
Navajo Inflow forecast trend since January

Forecast Date Forecast 

(KAF) 

% of Avg

(1981-2010)

January 1st 550 75%

Mid-January 520 71%

February 1st 500 68%

Mid-February 475 65%

March 1st 440 60%

Mid-March 440 60%

April 1st 440 60%

Mid-April 380 52%

Overall, the Navajo inflow forecast has been decreasing since January due to 

below normal precipitation. The forecast did not change between March and 

April due to near normal precipitation in March.

Monthly Precipitation % of Average: San Juan Basin

January February

March April 1-20
Snow Conditions: SNOTEL Snow Water Equivalent

April 20, 2020

% Median SWE 

San Juan Basin: 89%

San Juan abv Navajo: 85%

Animas River Basin: 97%

2020: 380 KAF

2016: 567 KAF

1994: 716 KAF

2011: 576 KAF

SWE vs. runoff is not a 1-to-1 relationship; 

spring weather will play a role in the final 

outcome of observed volume.
What is driving the forecast: CBRFC Model Snow Conditions

Some SNOTEL locations have near normal conditions. However, upper elevation 

snow (>11,000’) in the CBRFC model is below normal due to a dry October which 

resulted in a slow start to the high elevation snow accumulation season. 

November 1st modeled snow was anywhere from 2-4 inch below normal. This has 

resulted in lower forecasts throughout the basin. 

Model SWE Median

2020 Model SWE 

Upper Model SWE (11,000’-13,000’+)

4/20 SWE:

85% Median
Percent of 

normal soil 

moisture

What is driving the forecast: CBRFC Model Soil Moisture Conditions

San Juan River Basin

Soil moisture conditions entering the winter season

Depending on spring weather and snow melt evolution, it is possible 

a portion of the runoff will be lost to the dry soils. The forecasts are 

accounting for this possibility.
Water Supply 

Forecasts (April-July)Navajo: 380 kaf (52% avg)Vallecito: 133 kaf (69% avg)Lemon: 37 kaf (67% avg)Animas: 270 kaf (65% avg)McPhee: 167 kaf (57% avg)Powell: 5300 kaf (74% avg) Most Probable forecasts

as of April 21st, 2020
With no spring peak release planned, releases are expect

between 500 and 1,000 cfs throughout the summer to maSJRIP recommended target baseflow in the critical habitaLatest Available Water Calculation


• Despite near-average snowpack, dry soils persist and are expecte

effect on runoff efficiency. Runoff forecasts throughout the basin average for this reason.

• Navajo Reservoir is expected to peak between 6060 and 6065 ft. 

are planned for this spring. Releases from Navajo Reservoir are eremain at or near the current level through spring runoff. 

• After runoff ends, Navajo releases will likely increase to accommo

season while maintaining the recommended target baseflow ranhabitat reach. Releases are expected to vary between 500 and 1,0

• Other Reclamation projects in the San Juan River Basin are not p

under the most recent runoff forecasts.

Summary
Reclamation Contacts:

Marc Miller970-385-6541 mbmiller@usbr.govSusan Novak Behery970-385-6560 sbehery@usbr.gov Ruth Swickard970-385-6523 rswickard@usbr.govReclamation Contacts:Marc Miller970-385-6541 mbmiller@usbr.govSusan Novak Behery970-385-6560 sbehery@usbr.gov Ruth Swickard970-385-6523 rswickard@usbr.gov

Useful LinksReclamation: www.usbr.gov/ucUSGS: water.usgs.gov/nwisCBRFC: cbrfc.noaa.gov