Where does the water go?

 I read today's Nature eAlert, Nature Geoscience Contents: Volume 16 Number 11

and was struck by a review which I could only partially see and the article:

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Locally surprising megafloods in Europe can be anticipated from
continent-wide observations.
Nat. Geosci. 16, 942–943 (2023).
https://doi.org/10.1038/s41561-023-01301-4

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Megafloods are rare and hence difficult to predict.
However, using a collation of historical flood observations across Europe,
it is now shown that recent megafloods could have been anticipated — local surprises
are in fact not surprising at the continental scale.

Megafloods in Europe can be anticipated from observations in hydrologically similar catchments
Miriam Bertola, Günter Blöschl, Milon Bohac, Marco Borga, Attilio Castellarin et al.
06 November 2023 Nature Geoscience 16 | doi:10.1038/s41561-023-01300-5
Megafloods that far exceed previously observed records
often take citizens and experts by surprise,
resulting in extremely severe damage and loss of life.
Existing methods based on local and regional information
rarely go beyond national borders and cannot predict these floods well
because of limited data on megafloods,
and because flood generation processes of extremes
differ from those of smaller, more frequently observed events.
Here we analyse river discharge observations
from over 8,000 gauging stations across Europe and show
that recent megafloods could have been anticipated
from those previously observed in other places in Europe.
Almost all observed megafloods (95.5%) fall within the envelope values
estimated from previous floods in other similar places on the continent,
implying that local surprises are not surprising at the continental scale.
This holds also for older events, indicating that megafloods
have not changed much in time relative to their spatial variability.
The underlying concept of the study is that catchments with similar
flood generation processes produce similar outliers.
It is thus essential to transcend national boundaries
and learn from other places across the continent to avoid surprises and save lives.

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Our son has a canoe-touring company in Germany and uses some of these gauges
to estimate the safety factor on the streams his groups paddle. He does
sometimes access the gauges near where I paddle here in Ontario.

For example:
Parks Canada water levels affecting the Severn canal system:
https://www.pc.gc.ca/apps/WaterLevels/?siteId=100419&lat=44.71941044950733&lng=-78.7716293334961&z=9
https://parks.canada.ca/lhn-nhs/on/trentsevern/info/infonet/rabattement-drawdown-forecast

Also https://wateroffice.ec.gc.ca/search/real_time_results_e.html?search_type=province&province=ON
for values for currently 532 stations

I chose one on the Black River:

Real-time data - subject to revision
Copyright Environment Canada(2023)

"Real-Time Hydrometric Data for BLACK RIVER NEAR VANKOUGHNET (02EC019) [ON]"

02EC019    "BLACK RIVER NEAR VANKOUGHNET"
Description of parameters:
6    "Discharge (daily mean values)"    m³/s

Date (EST)    Parameter     Value(m³/s)
2023-11-01 00:00:00    6    3.73
2023-11-02 00:00:00    6    3.74
2023-11-03 00:00:00    6    3.76
2023-11-04 00:00:00    6    5.04
2023-11-05 00:00:00    6    4.53
2023-11-06 00:00:00    6    4.06
2023-11-07 00:00:00    6    5.26
2023-11-08 00:00:00    6    5.90

And I also chose one relevant to Hurricane Hazel -

Real-time data - subject to revision
Copyright Environment Canada(2023)

"Real-Time Hydrometric Data for HOLLAND RIVER EAST BRANCH AT HOLLAND LANDING (02EC009) [ON]"

02EC009    "HOLLAND RIVER EAST BRANCH AT HOLLAND LANDING"
Description of parameters:
6    "Discharge (daily mean values)"    m³/s

Date (EST)    Parameter     Value(m³/s)
2023-11-01 00:00:00    6    0.552
2023-11-02 00:00:00    6    0.520
2023-11-03 00:00:00    6    0.490
2023-11-04 00:00:00    6    0.470
2023-11-05 00:00:00    6    0.459
2023-11-06 00:00:00    6    0.491
2023-11-07 00:00:00    6    0.530
2023-11-08 00:00:00    6    0.514

The Holland River discharge is a factor 10 times lower than that of the
Black River.

And we "know" what happen here in October 1954.
Hurricane Hazel was Toronto’s perfect storm
So the data is in. No acts of "god" or even "God". We now know the certainty of an uncertain future rest in our hands - mine aren't webbed so I must depend on conservation measures - to get by with a little help from my friends, as it were. I wonder if there is some webbing between my toes?

WOB