The document summarizes operations and forecasts for Hungry Horse and Como reservoirs in 2012 and 2013. In 2012, Hungry Horse inflows were much higher than forecasted due to record high June precipitation, exceeding flood stage on the Flathead River. The 2013 outlook projects near-average inflows at Hungry Horse and below-average inflows at Como based on initial forecasts. Both reservoirs began 2013 at near-average elevations.

1. 2012 Operations and 2013 Outlook
for Hungry Horse and Como

2. Hungry Horse Forecasted and Actual Inflow
for 2012
Forecast Month Forecast Volume Forecast Volume
Jan-Jul May-Sep
(% of average) (% of average)
Jan 92 92
Feb 96 97
Mar 93 95
Apr 102 104
May 105 94
June 107 94
Actual 124 114
June-July runoff forecast was 880 kaf (92%). Actual June-
July runoff was 1263 kaf (131%)

3. NWRFC ESP forecasts
• June 4, 2012 – June-July volume of 784 kaf
(82%)
• June 15, 2012 – June-July volume of 951 kaf
(99%)
• June 25, 2012 – June-July volume of 1040 kaf
(108%)
• June 29, 2012 – June-July volume of 1173 kaf
(122%)
• Actual - June-July volume of 1263 kaf (131%)

5. June 2012 Precipitation (% of average)
Flathead Basin

6. Precipitation
• Expected future precipitation used in runoff
forecasts can vary dramatically from what
actually happens
• June 2012 precipitation was over 200% of
average (highest June total on record and 4 th
highest month ever on record). 8 inches
recorded at Hungry Horse Dam
• The result was much higher runoff in June than
was forecasted

7. Hungry Horse Operations, 2012
3565.00 60.0
Reservoir surcharged 0.5
ft to limit discharge
3560.00
50.0
3555.00
3550.00 40.0
Forebay (ft.)
3545.00
)
Discharge (kcfs)
30.0
Inflow (kcfs)
3540.00
w
o
k
F
c
s
f
(
l
CFMM (kcfs)
o
n
b
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a
E
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y
F
r
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f
)
(
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3535.00 20.0
3530.00
10.0
3525.00
3520.00 0.0
1-Mar-12 1-Apr-12 1-May-12 1-Jun-12 1-Jul-12 1-Aug-12 1-Sep-12

8. Local Flood Control
• Hungry Horse is operated to help keep the
Flathead River at Columbia Falls below 14 ft
if possible.
• Flows can be reduced down to a minimum of
300 cfs if there is room in the reservoir to
store
• The Flathead River at Columbia Falls can
often exceed flood stage even with reduced
flows depending on flow in the Middle and
North Forks

9. Flathead River at Columbia Falls
• There were 12 days in 2012 when the
daily average natural flow at Columbia
Falls exceeded the flood flow of 51,800 cfs
• The actual regulated flow at Columbia
Falls exceeded flood flow once for 13 hrs
on June 27 with a peak stage of 14.18 ft or
2 inches above flood stage

10. Hungry Horse 2013 Outlook
• As of Oct 15, 2012, Hungry Horse was at
elevation 3547.3 ft which is above average
for this time of year but typical for years
with the 10 ft. draft on September 30
• Currently releasing minimum flows
• Will continue to release minimum flows
until flood control requires higher releases

11. Hungry Horse 2013 Outlook (cont.)
• NWRFC ESP water supply forecast
(issued Oct 12) is around 90% of average
for April-July inflow volume into Hungry
Horse
• The first official operating forecast will be
released in January 2013

12. Como Operations (WY 2012)
2010 Forebay (ft) 2009 Forebay (ft) 2011 Forebay (ft) 2012 Forebay (ft)
4250.00
4240.00
4230.00
4220.00
4210.00
R
o
n
e
a
E
v
s
r
t
f
)
(
l
i
4200.00
4190.00
4180.00
1-Oct 1-Nov 1-Dec 1-Jan 1-Feb 1-Mar 1-Apr 1-May 1-Jun 1-Jul 1-Aug 1-Sep

13. Como 2013 Outlook
• As of Oct 15, 2012, Como is at elevation
4200.8 ft which is average for this time of
year
• NWRFC ESP water supply forecast (issued
Oct 18) for the Bitterroot near Darby is
around 70% of average for April-July runoff
volume
• Como nearly always fills even in drier years.
2001 was the last year it did not fill but within
3 ft of full