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Nov 6
2007:
Who stopped the discharge? Will remedial repairs have
to wait 'til Spring?
Oct 13
2007:
The Lake has dropped 20mm/day, 2cm/day or 0.8inch/day
since the re-crest on Aug 20th and will be down two full
metres on Nov 13th based on target date analysis by
TrendLines Research;
and down 3 full metres by December 17th 2007; The 2008
freshet will commence on May 10 2008. As of Oct 8, YTG Officials
presently estimate
that the waters will not recede 2m
until February and YTG has not offered an estimate on the 3m
threshold. Their best efforts forecast is the
black line
on our chart below.
Oct 9
2007:
At 1am this morning, the water level was down exactly 1
metre from the Aug 20 re-crest of the 2007 freshet (2.988m
on chart). Pretty good, eh!
Oct 3
2007:
The Lake has dropped 19mm/day, 1.9cm/day or 0.75inch/day
since the re-crest on Aug 20th and will be down one full
metre near Oct 11th based on target date analysis by
TrendLines Research;
and down 2 full metres by December 1st 2007; and down 3
metres from the 2007 crest by January 15th 2008. The 2008
freshet will commence on May 10 2008. As of Oct 8, YTG Officials
presently estimate
that the waters will not recede
two metres until
February and they have no estimate for stakeholders wrt the
3-metre threshold.
This profile
can be altered dramatically by YTG's tampering with outflows
downstream of Marsh Lake. By our analysis of
temperatures and precipitation in 1981, it certainly appears
that the record levels in 1981 were caused by such actions.
Below is TrendLines
baseline study of the 2007 recession profile. Similar to the
3-stage baselines of the cresting advance, there will
be a series of baselines on the downslope as well.
Note by the Oct 4th comparative graph that the threshold
dates have been advanced with the change in recession rate
from 16mm/day in Aug & early Sept to a more aggressive
24mm/day:
Monday Sept 24th 5am:
Water Level is down 15mm (1.5cm) over last 24hrs; and down
48mm (4.8cm) over the last 48hrs.
Present Level is lower by a total 579mm (5.79cm/23.1") to
3.409m on the Chart over 35 days. During the course of
this analysis, our updates have transitioned from three
times per day to daily. With receding waters in
pattern, our future updates will henceforth be issued
weekly...
~~~ The Lake has dropped 17mm/day, 1.7cm/day or 0.6inch/day
since the re-crest on Aug 20th and will be down one full
metre on Oct 14th based on target date analysis by
TrendLines Research;
and down 2 full metres by December 13 2007; and down 3
metres from the 2007 crest by February 6 2008. The 2008
freshet will commence on May 10 2008. YTG Officials
presently estimate that the waters will not recede a full
metre until Nov 6th. Below is TrendLines
baseline study of the 2007 recession. Similar to the
3-stage baselines of the cresting advance, there will likely
be a series of baselines on the downslope as well:
Sept 23 2007 ~ The Lake has dropped 17mm/day, 1.7cm/day or
0.6inch/day since the re-crest on Aug 20th and will be down
one full metre on Oct 19th based on target date analysis by
TrendLines Research;
and down 2 full metres by December 21 2007; and down 3
metres from 2007 crest by February 21 2008 ~
Sept 21 2007 ~ The Lake has dropped 16mm/day, 1.6cm/day or 0.6inch/day
since the re-crest on Aug 20th and will be down one full
metre on Oct 21st based on target date analysis by
TrendLines Research;
and down 2 full metres by February 21 2008; and down 3
metres from 2007 crest by March 21 2008. The 2008
freshet will commence on May 10 2008 ~
Sept 18 2007 ~ The Lake has dropped 15mm/day, 1.5cm/day or
0.6inch/day since the re-crest on Aug 20th and will be down one full
metre on Oct 22nd based on analysis by
TrendLines Research.
Our target date for remedial work requiring water levels to
be down two full metres is initiated today as March 21st
2008.
YTG's long term
outlook set yesterday forecasts levels to be down 1.3m from
the crest by Jan 3rd 2008.
Remedial work requiring water levels 3 metres lower than the
2007 crest must wait until April 20 2008, but caution is
required as the waters will most probably recommence rising
21 days later on May 10th 2008 ~
Sept 17 2007 ~ The Lake has dropped 15mm/day, 1.5cm/day or
0.6inch/day since the re-crest on Aug 20th and will be down one full
metre on Oct 22nd based on analysis by
TrendLines Research.
BREAKING NEWS: YTG released a
new graph today further postponing their target date
for this threshold from Oct 20 (set Sept 11) to Nov
6th.
Sept 15 2007 ~ The Lake has dropped 15mm/day, 1.5cm/day or
0.6inch/day since the re-crest on Aug 20th and will be down one full
metre on Oct 22nd based on analysis by
TrendLines Research ~
Sept 14 2007 ~ The Lake has dropped 15mm/day, 1.5cm/day or
0.6inch/day since the re-crest on Aug 20th and will be down one full
metre on Oct 23rd based on analysis by
TrendLines Research.
A major storm will hit SW Yukon over the weekend dumping as
much as 2" (50mm) rain. Most of this is beyond
the Marsh Lake watershed but cumulative precip will
likely produce a significant anomaly in the recession
advance before returning to the chart's baseline in about seven
days ~
Sept 12 2007 ~ The Lake is dropping 16mm/day, 1.6cm/day or
0.6inch/day and will be down one full metre on Oct 22nd ~
Sept 11 2007 ~ The Lake is dropping 15mm/day, 1.5cm/day or
0.6inch/day and will be down one full metre on Oct 23rd ...
not YTG's
Oct 1st
estimate ~
BREAKING NEWS:
YTG has broken with its stubborn estimate (set Aug 16)
that the lake will be down one metre by
Oct 1st.
A new YTG graph released today moves this critical date to
Oct 20th. This concurs with TrendLines Research
steadfast position over the past two weeks that the waters
would not recede to this threshold before Oct 21st.
This update chart should show that receding waters are on course
for that date vicinity:
Use
Internet Explorer 7's new Zoom tool at the bottom
right of your browser screen or <Control +> to
magnify & <Control -> to reduce.
~~~ Latest
Marsh Lake water level RECORD: 2007/Aug 14th -
Tuesday 1pm & tied Aug 19th - Sunday 10pm &
again Aug 20th - Monday 10pm:
2007: Aug14/19/20: 653.357 base + 3.988 = 657.345 metres GSCD
(35.3cm/14" over '81)
1981
Sep15: 653.357 base
+ 3.635 = 656.992 metres GSCD
2004 Aug28:
653.357 base + 3.432 = 656.789 metres GSCD
Marsh Lake rose 1metre
from June 30th to Aug14th. On Aug 20th, the
waters began to recede. YTG originally
predicted that the dikes would have relief on Aug
2nd. Will YTG be similarly wrong about how
long 'til the waters are down a full metre to begin
remedial work on septic/holding tanks, weeping beds,
water systems, docks & foundations?
YTG has been
consistent since mid August that Marsh Lake will
recede one metre (3cm/day) from its freshet re-crest by
Oct 1st. However,
with waters receding at only the rate of 1.7cm/day
due to increased rainfall in 2007,
TrendLines Research
has been forecasting since Aug 31st that remedial work requiring the
waters to be down by one metre will not be able to proceed 'til
at least Oct 21st:
The 1981 freshet crest
set a subsequent (and Record) high on Sept15th.
Did YTG and/or Yukon Energy manipulation of
discharge flows reverse the receding waters?
How did the crest miraculously rise 10" (24cm) w/o
assistance from rain, high temp's or regional forest
fires?
 |
The latest six-decade Record High Water Level was
marked at 1pm Tuesday August 14th
2007, retouched Aug 19th & again Aug 20th. Marsh Lake
surpassed the previous 1981 Mark by 14 inches/35cm & the
2004 Mark by 22in/56cm.
At this
latter stage of the freshet, the daily weather
blog has been discontinued ...
About Crests
of Freshets
-
Consider that the recent near record 2004 crest was not set
until August 28th. Back in 1981 the waters set a
then Record
High Crest Aug 15th, fell 12cm (5") over the next three
weeks and came back with a vengeful 24cm (10") to
set an all-time Record Peak High on Sept
16th of that year. Over six decades of record
keeping, the freshet crest is usually Aug 23rd.
During
August the 2007 crest has advanced along a baseline
of 3mm/day.
This is a lesser rate than the normal post surge
Crest Creep rate of 7mm/day. Applying historic median
activity to this year's freshet would have indicated a
target crest of 4.09m (657.450m) on Aug
27th 2007. But a more likely scenario, using
the similar 1981 crest advance and according to the current
trendline ... is a crest of 3.990m
(657.347m) if the Crest Creep lasts the normal 35
day length.
The Chart above shows that the original 1981 baseline was breached
about Aug 27th but the freshet still came back to
successfully challenge its false crest. In the
end, the Phase2 baseline for 1981 was a
horizontal baseline that is best represented by the
3.4m x-axis line.
Or ... was
the freshet permanently receding in September ...
until interference with Discharge Flows caused a
re-advance of the Crest?
Web-based weather data
for mid-Sept 1981 reveals no rain anomalies
(7mm is max on Sept14) or
extreme high temp (max 16C on Sept7) anomalies. The 10" or 24cm
surge in Sept would have required sustained
watershed temps in the 30's or in excess of 200mm of
rain. No such record events are recorded.
Similarly, there is no forest fire related acitivity.
It is more plausible to speculate that normal
Discharge rates were impeded at the Locks or Hydro
Dam.
The 2007 freshet has
breached three baselines and is now receding as
shown in the first chart above. This type of baseline analysis allows
study and separation of the underlying glacial meltwater from
forcing by occasional showers or high temp episodes. The gap area
above the baselines represents rainfall (eg Aug7 &
Aug19)
and bonus glacier melt (eg Aug 18) on the hot days.
The full effect of rainshowers takes seven days to
diminish. Marsh Lake waters rose 60mm or
6cm/day during Phase 1. Please Zoom in on
the chart for higher resolution.
Wind Piling: Altho
locals deny it, my gauge observations confirm that Marsh Lake is susceptible to
the phenom of "piling" whereby consistent strong winds can
push waters higher at the leeward shore and temporarily reduce
levels at the windward end. Eventually, when the wind
subsides, the water "sloshes" back from whence it came.
This was most
evident in the course of events witnessed Aug 4/5. Saturday's
brisk NW winds pushed the waters
eastward away from the measuring station at the Purple
Caboose; and the level receded 1.5cm. With light winds
and in the absence of watershed rainfall on Sunday, the
chart shows that the water all came right back.
And Sunday's showers will surely cause levels to surpass Friday's record high of 3.977m.
BTW, this process can pile water up several feet at the
leeward end of the Great Lakes with the correct conditions,
particularly Lake Erie with WNW winds.
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"Are we
there yet?" -
The dysfunctional YTG
calls for the elusive Peak stem from their lack of comprehension of the post surge
crest creep factor. Historically it lasts "35 days"
after the initial freshet's robust surge and adds 24cm to
rising levels. While this would normally
reflect a Peak on Aug 23rd, this year's Crest Creep
commenced four days later than usual and thus
indicated a
target Crest on Aug 27 of 4.09m (657.45m).
YTG
Officials have had a litany of miscalls because they
declared their first Peak on only the "9th day"
after the initial freshet surge. Their
"umpteenth" others incl the Aug 15th
Declaration were similarly misguided as the last one was
made on only Day 23 of the 35-day Crest Creep period.
When YTG Officials
declared that Marsh Lake
was peaking at 3.9m on
Aug 1st, they exposed themselves as not being students of history, geography, hydrology or
meteorology! The waters have since risen 8.3cm
above the 3.9m level they committed to as seen in the chart above.
Seldom have their plethora of prediction
efforts survived even 24 hours. Sometimes
their forecast peaks are breached before their
comments reach the YTG website. Now that's
really embarrassing, eh! |
The ramifications of
faulty projections by YTG involve issues including
premature winding down of sandbagging, dike water-saturation and likely breaches and overtopping with
robust wave action September thru Thanksgiving.
A final concern is the
misconception YTG is giving stakeholders of the extent
of remedial work that can be undertaken before freeze-up.
Just as YTG Officials miscalculated the crest level
& crest timing, they are presently overly optimistic
with their forecasts of the rate whereby waters will recede. There
is reasonable potential for Autumn levels to be 16"
higher than shown on the YTG graphs ... from Labour Day
to Christmas.
This would
indicate that today's levels will drop only 18" to
31" by freeze-up ... leaving slim hope for
repairs to septic tanks, weeping beds, holding
tanks, foundations and water systems. (rev
2007/9/6) |
|
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1981
Profile & Tracking of Historic Freshet Medians
Chart #3 ~ This is a profile of
the previous 1981 Record Year (red) amid the channel of low/high
Records. Note that a false record crest of
3.514m occurs on Aug 15th; the waters receded 12cm (5") over
the next 3 weeks and advanced impressively 24cm (10")
to set on Sept 16th what was to become the all time High
Water Mark for
26 years (3.635m & 656.992 metres GSCD).
The gold line represents
the median of all freshets. It is clear
that in a six decade
perspective, crests occur after mid August.
Using the six-decade median
(gold line),
the Marsh Lake freshet robust surge starts May 10th followed by 35
days of Crest Creep from July 20 to a Cresting on Aug 23rd.
Prior to July 20, the surge advances at an avg rate of
3cm/day. When accompanied by heavy snow packs and
lotsa precipitation (as in 2007), the surge can generate
10cm/day bursts. During the Crest Creep period, the
crest advances at approx 7mm or 0.7cm/day.
After the crest peaks, waters
recede an avg 4mm/day, 3cm/week, 12cm/month until year-end and a
brisker 13mm/day, 9cm/wk, 40cm/month pace from January to
May 9th. But these rates reflect only the median 2.3
metre or 7 foot drop. During record years, the waters
decline almost 4 metres (13 feet). |
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