Guest Post Written by Cabot Martin:


The North Spur stability issue is the single greatest Risk
to the Muskrat Falls Project.
Nalcor’s handling of this Risk has been neither sufficient nor

Based on informed expert opinion, it is apparent that (quite
apart from downstream safety issues), a North Spur collapse could lead to the
loss of the Province’s entire multi-billion investment in the Dams and
Generating Facilities presently being constructed at Muskrat Falls and the full
abandonment of the Muskrat Falls site.

On July 2, 2015, I wrote the Minister responsible for Dam Safety,
Hon. Dan Crummell on this issue; early last week I received an
answer from the Minister dated July 30th , 2015.

In the meantime, Nalcor posted a North Spur Dam Break analysis by Hatch Consultants dated June 26,2015 on its website. 

On August 7th, I replied to the Minister’s letter
as set out below.

It points out that he is using Dam Safety Guidelines
that are simply not applicable  to cases
like the North Spur.

Further that Nalcor has severely undermined the scope and
validity of the Hatch June 26th North Spur Dam Break Study.

The public deserves to know that this matter is being properly
handled. The Minister’s letter gave me no comfort in that regard. That is why
this letter was written.

7, 2015
The Honourable Dan Crummell
Minister of Environment and Conservation
4th Floor, West Block
Confederation Building
St. John’s, NL   A1B 4J6
Dear Mr. Minister:
Thank you for your letter of July 30,2015 in response to my
urgent letter of July 2,2015 concerning the North Spur stability problem at the
Muskrat Falls hydro project on the Lower Churchill River in Central Labrador.

Unfortunately I can draw no comfort from your reply as it is
based on a number of serious misconceptions.

(1) The Canadian
Dam Association (CDA) Dam Safety Guidelines you cite are not at all applicable to the geotechnical conditions at the North Spur.
Nor can they provide a proper basis for either Nalcor’s North Spur engineering
design or your Department’s safety review of Nalcor’s North Spur plans.

They are applicable to the North and South Concrete Dams on
the other side of Muskrat Falls but not
to the North Spur.

The CDA Dam Safety Guidelines have been developed and are applicable only to dam
structures where all materials used in construction of the dam in question, from
the foundations up, are known as to their physical strength, chemical
composition and load bearing characteristics and have been engineered and specified
by competent engineers in accordance with the Guidelines.

The North Spur is not like that at all – the North Spur is a
highly variable, heterogeneous natural accumulation of sand and clay which
contains unstable glacio-marine clays that 
have a tendency to create landslides. The North Spur also contains many
relatively thin sand lens mixed in with the glacio-marine clay – such sands can
act as a “trigger sand ” and play an important role in setting off a landslide.

It is not surprising then, that I am reliably informed by a very
experienced  hydro engineer that the CDA
Dam Safety Guidelines do not apply and are
not meant to apply
to situations like the North Spur.

There is no way the CDA can be held responsible for Nalcor’s
flawed North Spur plan.

Page 1 of 4

Consequently you should seriously review this matter with
your officials and develop a more appropriate basis for the execution of your
oversight and regulatory duties.
(2) The second
misconception is just as serious.

You have cited a June 26, 2015 study by Hatch entitled
“North Spur Dam Break Analysis”  as a
basis for your approval of Nalcor’s current activities on the North Spur.

I note that neither the Joint Review Panel in 2010 nor the
Minister and officials prior to their approval of Muskrat Falls river closing permits
in the spring of 2013 had the benefit of this (or any other) North Spur Dam
Break Study — which came over two and a half years after project sanction.

In any event, this new Hatch 2015 North Spur Dam Break Study
is very different in scope and in other aspects from the Muskrat Falls Dam
Break Studies prepared by Hatch back in 2010 for the two concrete dams at
Muskrat Falls (which were filed with the Joint Review Panel).

As noted below, I am preparing a detailed analysis of the
Hatch 2015 North Spur Dam Break Study and will forward it at an early date.

For now, I wish to focus on the interference by Nalcor in
the work of the consultant Hatch which is neatly summed up in a single sentence
in the Hatch report :

“The assumed breach bottom elevation for the analysis was specified by
NE-LCP to be 20.5 m,
which is the elevation of the top of the bentonite cutoff wall.”
(Hatch 2015 North Spur Dam Break Study page 2 Section 2.1).

“NE-LCP” stands, of course, for Nalcor Energy –Lower
Churchill Project.

The term “breach bottom elevation” is the lowest point to
which a North Spur slide and the resulting freed river will together cut the
North Spur down in the event of failure.
In other words , Nalcor
has “specified” (ie. imposed)  a very critical
 restriction on Hatch
, namely that
the down cutting will end when the river gets to the top of the bentonite
cutoff wall at +20.5 m above sea level from which it will flow in an “overtopping”
mode ( presumably as if the bentonite wall will act as a dam of some sort).
No engineering studies are offered in support of this idea.

This is obviously ludicrous as the bentonite cutoff wall on
the upstream side of the North Spur as proposed would be a relatively slender
structure, not seated in bedrock and designed only to prevent upstream seepage.

The bentonite cutoff wall cannot possibly withstand the
enormous forces associated with a North Spur failure and consequent river
release. It will be quickly swept away.
Page 2 of 4

I am informed by an experienced
hydro engineer that the consequences of a North Spur failure,
“from a financial perspective
would be unimaginably catastrophic”  due
to the very large
expenditure required for a
repair due to erosion of the Spur clay foundation down to below sea level. …”
He continued:
“The cost
would be so high, that a more economical alternative would likely be to abandon
the site and spend the repair moneys on a re-design and construction of the
Gull Island Dam, taking advantage of the lower tailwater level resulting from a
dam break in the North Spur to increase the capacity.”

In other
words, your position (seeking to refute mine) that “the river cutting a new
channel and by-passing Muskrat Falls is extremely unlikely” is simply not correct
based on the advice of a very experienced hydro engineer very familiar with Lower
Churchill Hydro projects.

Indeed that very
senior hydro engineer informs me that in the event of a North Spur failure, the
down cutting at the location of the North Spur (which will of course disappear)
will continue to a depth of      -10m to
-20m ie 10 to 20  meters below sea level.

That is 30 to 40 m
below Nalcor’s “specified” limit.

As the Hatch Report
itself repeatedly emphasises, the 
“breach bottom elevation” is probably the most critical variable in its
governing what it thinks will happen if the North Spur fails — governing
everything from Width of Breach to Peak Wave to Warning Time ( and thus to Loss
of Life downstream).

To impose a + 20.5 m
deepest cut restriction on Hatch in such a critical matter is simply wrong and
not in the public interest.

I am preparing, with the assistance of others, further
comments on a number of points in your letter of reply but you can understand
me when I say that getting clarity on the two points set out above is key to
completing that analysis.

Which brings me to my closing point.

Your letter refers to the work of the Joint Review Panel as
being somehow relevant to the problematic position we all now face. You should
be aware that while the Joint Review Panel had the benefit of a Dam Break Study
for the concrete dams at Muskrat Falls it
did not have a Dam Break Study for the North Spur which was only completed on
June 26,2015.

So I take no comfort there either.

Page 3 of 4

Indeed I find it passing strange that a proper full Dam Break Study for a North Spur collapse case was not
before the Joint Review Panel and has never been the subject of a public review
with all relevant geotechnical information being made public
especially where it deals with Quick Clay and landslide potential.

I urge you immediately change that.

And as Minister responsible for Dam Safety, I respectfully
suggest you engage the public via an open and transparent process on the North
Spur stability/Dam Break issue –  something it has never had.

If we, as a society, demand documentation and public review
to protect the environment, why not apply the same approach to Dam Safety, workplace
safety, human life downstream and the multi-billion dollar loss of our
investment in the Muskrat Falls generating facility currently under
construction ?
Cabot Martin
151 Waterfordbridge Road
St. John’s , NL
A1E 1C7

Cc Mr Jamie Chippett 
Deputy Minister Department of Environment and Conservation

Page 4 of 4

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Bill left public life shortly after the signing of the Atlantic Accord and became a member of the Court of Appeal until his retirement in 2003. During his time on the court he was involved in a number of successful appeals which overturned wrongful convictions, for which he was recognized by Innocence Canada. Bill had a special place in his heart for the underdog.

Churchill Falls Explainer (Coles Notes version)

If CFLCo is required to maximize its profit, then CFLCo should sell its electricity to the highest bidder(s) on the most advantageous terms available.


This is the most important set of negotiations we have engaged in since the Atlantic Accord and Hibernia. Despite being a small jurisdiction we proved to be smart and nimble enough to negotiate good deals on both. They have stood the test of time and have resulted in billions of dollars in royalties and created an industry which represents over a quarter of our economy. Will we prove to be smart and nimble enough to do the same with the Upper Churchill?


  1. The report references 20.5 meters, which is about 15 meters above the downstream water level, and about 65 meters above the deep pool located just downstream of Spirit Mountain. So in the dam break analysis they have been told to consider failure of the top half only?

    The Minister should direct Nalcor to release the report which recommends the 20.5 m elevation.

    Why is not all of this information public?

    What is there to hide?

    Why does our Government always just parrot what Nalcor state…

    What must be remembered is that there is no other example in the world where a geological feature like the North Spur is being used as a Natural Dam. Are the classical geotechnical empirical models still applicable?

  2. It is strange that Hatch did not include a sensitivity for a failure of the North Spur beyond the 20.5 meter cut off.

    The disclaimer from Hatch at the front of the document clearly states they have provided no comment on the suitability of the Client supplied data.

    What is the probability of failure of the North Spur?

  3. The North Spur is like the sword of Damocles. While the probability of collapse in any particular year may be low, it will eventually let go with no warning. An earth tremor, failure of the pumping system designed to keep water levels in the spur low, desalination of the clay caused by pumping out water that gets replaced with fresh rain water changes the chemistry of the clay allowing it to liquify, a few years of unusually heavy rains, or just plain back luck. Why would anyone sane person accept such catastrophic risks when there are so many alternatives to Muskrat Falls in the first place?