Here are two memos received from the Forest Service regarding flows
for
the Tuolumne River in California. The first is a seasonal advisory, and
the
second is an update with much better news, due to the recent heavy
storms
in the last couple of weeks. I will post updates as I receive them.
Here’s the first memo:
The following announcement is to inform boaters of the current
status
of expected flows on the Wild and Scenic Tuolumne River. Hetch Hetchy
Water and Power has informed the USFS that guaranteed flows between 950
to
1000 cfs at Lumsden launch will be available from July 2, 2001 through
August 11, 2001, monday through saturday (no sunday releases). Releases
will be made from 10:00 am to 1:30 pm, resulting in flows arriving at
Lumsden Launch at approximately noon.
Boatable flows will probably exist prior to this period, but cannot
be
guaranteed. At this date, April 4, Hetch Hetchy will release flows of
775
cfs between 8:00 a.m. and 11:00 a.m. through April 14th. These flows
are
augmented by natural inflow (currently approximately 250 to 300 cfs),
but
you should check river flows on the website
(http://s601dcascr.wr.usgs.gov/rt-cgi/gen_stn_pg?station=11283001) to
confirm total flow since natural inflow is weather dependent.
Based on current conditions, there is only a 50% probability of
boatable flows between April 14th and July 2. We will try to send
updates
regarding expected availability of flows every two weeks, as Hetch
Hetchy
updates their flow release schedule in response to effects of current
weather conditions. You can also call the USFS office at (209)
962-7825
for up to date flow information.
These unusual flow conditions are the result of:
1) a below normal snow pack (about 60%),
2) lower then usual upstream reservoir levels due to dam repairs last
year
3) projected energy needs due to the State power shortage
A second memo was just received:
BIG APRIL STORMS OPEN THE TUOLUMNE FOR BOATING 7 DAYS A WEEK
April 24 through Jun 3
The recent storms have dramatically changed flow forecasts on the
Tuolumne
River.
The last three storms have raised the average forecast of annual runoff
from 55% to 65% of normal. April is now at 215% of normal precipitation
and is credited with being the biggest month of this season for
precipitation.
Margaret Hannaford the Water Resource Manager at Hetch Hetchy Water &
Power
says this will greatly enhance the forecasted reservoir inflows enabling
significant additional power production at Kirkwood and Holm
Powerhouses.
Tuesday, 4/24 the Kirkwood powerhouse will begin to release 650 cfs into
the river around the clock well into June, and Cherry powerhouse will
begin
to operate at 50 to 60% capacity seven days a week at about 500 cfs.
The
minimum fish flows from upstream reservoirs will also be increased from
60
cfs to 125 cfs This new flow regime along with the South and Middle
Forks
of the Tuolumne (now at 350 cfs) should produce boatable flows at
Lumsden
from 1200 to 1800 cfs around the clock seven days a week, at least
through
June.
Sundays might be cut off after June 3, but flows will be available
Monday
through Saturday, through August 11.