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Fontenelle Dam Releases & Green River Flow Updates

1966 Telephone Island 2-512x219We will post upcoming flow changes as they become available, with the link to Fontenelle Dam daily release information.  Large boulders, rock sills and structures in the river bed pose a constant risk to boaters on this stretch of the Green.  High water has the potential to drastically alter instream characteristics, such as locations of gravel bars, riffles and holes.  Float times during high water can also be expected to decrease.  Low flows will reveal more obstacles for boats and longer float times.  Visitors should be aware of changing flows and the associated risks.  

March 21, 2017

Greetings,
Increasing forecasts of runoff for the remainder of March and possibly April will require further increases in releases from Fontenelle Dam. Releases will be increased according to the following schedule:

 March21_2017-FlowUpdate

Please note:
The current release schedule is subject to observed hydrology and is subject to change.
This notification supersedes all previously issued notifications and is current until a new one is issued. All times identified in this notification are Mountain Daylight Time and are not hour ending. 

Regards,
Jed Parker

 

 March 15, 2017

 

To:         Roger Williams, Glen Canyon Control Room,

 Steve Johnson, CRSP Management and Marketing Office     

           

From:     Jed Parker                       

 

Subject:  Fontenelle Operations

 

The forecasted inflow for Fontenelle Reservoir between the months of April and July is anticipated to be 1,738,000 acre-feet which is nearly 240 percent of normal. In addition, low-level elevation snow melt is flowing into the reservoir causing the pool elevation to increase nearly two feet over the last week. As the downstream threat from ice jams has passed, the dam releases are planned to increase from the dam in anticipation of large inflows this spring.

 

Therefore, dam releases will be steadily increased beginning Wednesday, March 15, 2017 and ending Thursday, March 30, 2017 according to the following table:

 

Date

Time (MDT)

Initial Release (cfs)

Change (cfs)

Final Release (cfs)

3/15/2017

10:00

1025

75

1100

3/15/2017

14:00

1100

100

1200

3/16/2017

10:00

1200

100

1300

3/16/2017

14:00

1300

100

1400

3/20/2017

10:00

1400

100

1500

3/20/2017

14:00

1500

100

1600

3/21/2017

10:00

1600

100

1700

3/21/2017

14:00

1700

100

1800

3/22/2017

10:00

1800

100

1900

3/22/2017

14:00

1900

100

2000

3/23/2017

10:00

2000

100

2100

3/23/2017

14:00

2100

100

2200

3/27/2017

10:00

2200

100

2300

3/27/2017

14:00

2300

100

2400

3/28/2017

10:00

2400

100

2500

3/28/2017

14:00

2500

100

2600

3/29/2017

10:00

2600

100

2700

3/29/2017

14:00

2700

100

2800

3/30/2017

10:00

2800

100

2900

3/30/2017

14:00

2900

100

3000

 

 

Please note: 

 

This directive supersedes all previously issued directives and is current until a new directive is issued.  All times identified in this directive are local time (Mountain Standard Time) and not hour ending

 

If there are any concerns or questions in regards to these operations, I can be reached at 801-524-3816.  Your cooperation is greatly appreciated.

 

Please note: 

 

This directive supersedes all previously issued directives and is current until a new directive is issued.  All times identified in this directive are local time (Mountain Standard Time) and not hour ending

 

If there are any concerns or questions in regards to these operations, I can be reached at 801-524-3816.  Your cooperation is greatly appreciated.


Regards,
Jed Parker

 

--------------------------------------------------------------------------------------------------------------

 

 

 

 

February 22, 2017

 

Greetings Fontenelle Stakeholders,

 

The following is an update on hydrology affecting the basin above Fontenelle Reservoir as well as anticipated operations at the dam.

 

 

As of February 22, 2017, the to-date snow pack in the basin above Fontenelle was at 192% of median for a total of 145% of the seasonal median, historically wedged between two other high snow pack years of 2011 and 1986. The following graph demonstrates the snow water equivalent (inches of water present in snowpack) as those years progressed through the season along with the median (average between the years 1981-2010) and the current year’s snowpack. 

 

Inline image 1

 

The following graph is a recounting of releases from Fontenelle in the years 2011 and 2016 (last year’s runoff) between the months of February and September. This graph is provided to demonstrate a high snowpack year (2011) compared to a roughly average snowpack year (2016). 

 

Inline image 2

 

Fontenelle is currently releasing 1,025 cfs (cubic feet per second) which is expected to continue until the threat from downstream icing has passed. At which time releases will be increased to near power plant capacity (around 1,300 cfs). Going forward and depending upon further accumulation of snowpack, releases as early as mid-April may reach 4,000 cfs with early June releases reaching between 8,000 and 11,000 cfs.

 

While a variety of snowpack situations may play out over the coming months it is important for Reclamation to convey to stakeholders that the Colorado Basin River Forecast Center is now predicting a near 50% probability that the snow pack this year may be greater than the highest year on record for the basin above Fontenelle (1986). The facilities and procedures in place at Fontenelle Dam are sufficient to handle even the highest flows currently forecasted.

 

We look forward to working with stakeholders as we continue to analyze snowpack and reservoir operations and encourage anyone with concerns to contact us directly. A Fontenelle working group meeting will be held at Seedskadee National Wildlife Refuge in Green River, Wyoming on April 19, 2017, at 10:00 a.m.

 

Regards,

 

 

Jed Parker

 

-- 

Jed Parker, P.E.

Engineer | UC Water Resources Group

 

Last Updated: Mar 22, 2017
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