7172 they were primarily meant to break the ice and

[71][72]
They were
primarily meant to break the ice and prevent troops and heavy military equipment from crossing the Volga river and
Ivankovo Reservoir .
[73]
This began with the blowing up of the Istra
( ru )
waterworks reservoir dam on 24 November 1941.
On 28 November 1941, the water was drained into the Yakhroma and Sestra Rivers from six reservoirs ( Khimki
( ru )
,
Iksha
( ru )
, Pyalovskoye
( ru )
, Pestovskoye
( ru )
, Pirogovskoye
( ru )
, and Klyazma
( ru )
reservoirs), as well as from Ivankovo

The Soviet winter counter-offensive, 5 December 1941 – 7
May 1942
A Soviet machine gunner covers
attacking infantry near Tula, in
November 1941.
Reservoir using dams near Dubna .
[71]
This caused some 30-40 villages to become partially submerged even in the
severe winter weather conditions of the time.
[71][74]
Both were results of Soviet General Headquarters' Order 0428
dated 17 November 1941. Artificial floods were also used as unconventional weapon of direct impact.
[75]
Soviet counteroffensive
[ edit ]
Although the Wehrmacht's offensive had been stopped,
German intelligence estimated that Soviet forces had no
more reserves left and thus would be unable to stage a
counteroffensive. This estimate proved wrong, as Stalin
transferred over 18 divisions, 1,700 tanks, and over 1,500
aircraft from Siberia and the Far East.
[76]
The Red Army
had accumulated a 58-division reserve by early
December,
[42]
when the offensive proposed by Zhukov
and Vasilevsky was finally approved by Stalin.
[77]
Even
with these new reserves, Soviet forces committed to the
operation numbered only 1,100,000 men,
[67]
only slightly
outnumbering the Wehrmacht . Nevertheless, with careful
troop deployment, a ratio of two-to-one was reached at
some critical points.
[42]
On 5 December 1941, the counteroffensive for "removing
the immediate threat to Moscow" started on the Kalinin
Front. The South-Western Front and Western Fronts began their offensives the next day. After several days of little
progress, Soviet armies retook Solnechnogorsk on 12 December and Klin on 15 December. Guderian's army "beat a
hasty retreat towards Venev" and then Sukhinichi. "The threat overhanging Tula was removed."
[38] :44–46,48–51
On 8 December, Hitler had signed his directive No.39 , ordering the Wehrmacht to assume a defensive stance on the
whole front. German troops were unable to organize a solid defense at their present locations and were forced to pull
back to consolidate their lines. Guderian wrote that discussions with Hans Schmidt and Wolfram von Richthofen took
place the same day, and both commanders agreed that the current front line could not be held.
[78]
On 14 December,
Franz Halder and Günther von Kluge finally gave permission for a limited withdrawal to the west of the Oka river ,
without Hitler's approval.
[79]
On 20 December, during a meeting with German senior officers, Hitler cancelled the
withdrawal and ordered his soldiers to defend every patch of ground, "digging trenches with howitzer shells if
needed."
[80]
Guderian protested, pointing out that losses from cold were actually greater than combat losses and that
winter equipment was held by traffic ties in Poland.