France 1: 25,000, GSGS 4347, Terrain Study Map showing inundated areas.
1.
AREA UNDER CONSIDERATION: The area
under consideration is bounded on the South by the line CARENTAN-PERIERS-LESSAY;
on the West by the line LESSAY-LA HAYE DU PUITS-ST. SAUVEUR LE VICOMTE-VALOGNES;
on the North by the low east-west ridge extending from VALOGNES to QUINEVILLE;
and on the East by the English Channel and the CARENTAN Channel.
2.
GENERAL TOPOGRAPHY OF THE AREA:
DRAINAGE SYSTEM:
The area under consideration is drained primarily by the DOUVE River
and its tributaries. The average depth of the river valley is 1½
to 2 miles and the slope of the river bed is very gantle. The current
does not exceed 2 mph. The DOUVE River is 20' to 80' wide and at least
3' 3" deep as far up as ST. SAUVEUR LE VICOMTE and there is barge
traffic between CARENTAN and ST. SAUVEUR LE VICOMTE. The banks of the
DOUVE vary from 4' to 8' high. The CARENTAN Channel is 100' to 200'
wide with flood banks of 6' to 8'. If these flood banks were destroyed,
the lowlands on either side would be flooded at high tide.
The inundations shown on the attached map are artificial. The inundated
area in the river valleys is controlled by locks and sluices at LA BARQUETTE
(398969). The depth of the flooding varies from 60" at 3786 to
only soft ground on other places. If the locks were destroyed, the River
DOUVE would be tidal as far up as the confluence of the MERDERET; but
the flooding would be erratic and even unlikely in summer. If the locks
were properly controlled, it would take an estimated 7 days for the
inundated areas to drain but the ground would still be saturated and
soft and an obstacle to vehicles of all kinds.
The inundated area back of the beach is likewise artificial, being normally
drained by a complex network of field drains. The larger drains have
been blocked from 50-150 yards back of the beach (see map) to obtain
this inundation. Were these drains cleared it is estimated it would
take 10 days to drain this area and even then it would be very soft
and unsuitable for vehicles of all types. Even infantry would find it
difficult to deploy, though some passageways could be found.
RIDGE SYSTEM.
There are two clearly defined ridges in the area. One runs east-west
from VALOGNES to QUINEVILLE, the other generally east-west from the
vicinity of ETIENVILLE to mouth of River AY. There are no other clearly
defined ridges in the area, the terrain being gently rolling, and of
no definite pattern. The two ridges excepted, maximum elevation in the
area seldom exceeds 40 meters. There is high ground near MONTEBOURG
(110 meters) and south of the DOUVE there are two high hills at 165885
and 185875 of 120 and 130 meters elevation respectively.
ROUTES:
The main routes in the area are as follows:
(1) The CARENTAN-VALOGNES highway. (North-South).
(2) The VALOGNES-ST. SAUVEUR LE VICOMTE-LA HAYE DU PUITS-LESSAY highway.
(North-South).
(3) The VALOGNES-ETIENVILLE-PERIERS road. (North-South).
(4) The ST. SAUVEUR LE VICOMTE-STE. MERE EGLISE road. (East-West).
(5) The CARENTAN-LA HAYE DU PUITS road. (East-West).
The first two are military roads and are in good repair. The latter
are all weather roads, 16' - 18' wide, but probably have not been maintained
since 1940. There is an adequate network of minor roads throughout the
area. The width of roads and the ditches and hedges along the roads
are indicated on the map. There is a double-track railroad from CARENTAN
to VALOGNES in the area and a single-track railroad from CARENTAN to
LA HAYE DU PUITS.
General Nature of the Terrain:
The area north of CARENTAN and east of the DOUVE as far north as VALOGNES
is a low marshy coastal plain. The ground is flat to gently rolling.
The streams are sluggish and meandering, flowing through broad valleys.
Land that is not under water or marshy is in pastures, cultivated fields,
and orchards. Hedges and lines of trees are common between fields and
there are many drainage ditches, particularly near the inundated areas
and alongside of roads.
South of the DOUVE, the PRAIRIES MARECAGEUSES and the PRAIRIES MARECAGEUSES
DE GORGES are of a marshy nature drying to some extent in the summer.
The PRAIRIES MARECAGEUSES DE GORGES is very near the source of the River
AY northwest of PERIERS and thus is formed an almost continuous link
of low ground across the neck of the COTENTIN Peninsula. Between PERIERS
and the DOUVE the high ground is in woods and pastures.
3.
MILITARY ASPECTS OF THE TERRAIN:
AVENUES OF APPROACH AND LINES OF COMMUNICATIONS:
There are only 5 roads and one railway from the South. The roads cross
the DOUVE River at LE MOULIN, CARENTAN, BEUZEVILLE LA
BASTILLE, PONT L'ABBE (ETIENVILLE), and ST. SAUVEUR LE VICOMTE.
The first, second and last are on military roads, class 50 or better.
The railroad crosses on 3 successive bridges northwest of CARENTAN.
Approaches from the West include the 5 crossings of the DOUVE at ST.
SAUVEUR LE VICOMTE, STE. COLOMBE, RUE DU PART, L'ETANG BERTRAND , and
NEGREVILLE. There is the approach through LA HAYE DU PUITS which does
not cross the DOUVE until well within the area under consideration.
There are also numerous avenues of approach from the North, the primary
ones being the CHERBOURG-CARENTAN Highway, the ST. PIERRE EGLISE-VALOGNES
road, and the QUETTEHOU-VALOGNES road, all running south through VALOGNES.
There is an extensive network of minor roads throughout the area and
communications are good in any direction except across the inundated
area back of the beach. Construction and/or maintenance of communications
here is a major engineering project. Every effort should be made
to seize crossings over this inundation trior to their destruction by
the enemy.
Crossing of the CARENTAN estuary from LA BARQUETTE to the sea is difficult
due to the treacherous soil conditions. Vehicles cannot cross the estuary
except by bridges and ferry at LE MOULIN. Other suitable crossings
may exist for infantry, but these would be hazardous until reconnoitered
and marked.
OBSTACLES:
The chief obstacles in the area are the inundated areas. If these are
to be maintained, LA BARQUETTE locks must be captured intact. The soil
under inundation is generally clay and gives very poor bearing when
wet. These areas are effective obstacles against wheeled and tracked
vehicles. Road blocks and mines are known to exist in the areas adjoining
the beaches. The ditches and embankments along the roads defile them,
preventing vehicles from deploying across country in many places. This
render motor columns vulnerable. The many tree lines, orchards, hedgerows,
ditches and defiled roads constitute somewhat of an obstacle to glider
landings.
CONCEALMENT AND COVER:
Cover and concealment are only fair in the area north of the Douve River,
since the terrain is only gently undulating. There is concealment from
ground observation but not from aerial observation. South of the DOUVE,
in the bocage type country, cover and concealment are satisfactory.
Due to the amount of vegetation, camouflage should be comparatively
easy. Vegetation is predominantly light green in color. Camouflage nets
should be pre-garnished accordingly.
OBSERVATION:
Ground observation is relatively poor due to the undulating nature of
the country and the numerous hedge rows, orchards and lines of trees.
South of the DOUVE, the wooded areas and the broken, rocky nature of
the country makes observation difficult. There is a notable absence
of commanding terrain. Observation from the VALOGNES, QUINEVILLE ridge
permits interdiction fire by enemy artillery on roads ans intersections
from ST. MERE EGLISE to MONTEBOURG.
FIELDS OF FIRE:
Within the area, fields of fire necessarily suffer from lack of observation.
However, short fields of fire across individual fields are excellent.
4.
CRITICAL TERRAIN FEATURES:
The inundated valleys of the DOUVE and its tributaries.
The inundated area back of the beaches.
The locks at LA BARQUETTE.
The lock at 448927.
The crossings of the DOUVE and its tributaries.
The center of communications VALOGNES and the many avenues of approach
from the North.
The east-west ridge from VALOGNES to QUINEVILLE.
The east-west ridge extending from north of the River AY to PONT L'ABBE
(ETIENVILLE).
The high ground back of the beach.
The communications bottleneck at CARENTAN.
5.
TACTICAL EFFECT OF THE TERRAIN:
The inundated areas offer excellent protection from the South and
the West once the crossings have been seized or destroyed. Destruction
of the crossings from the South will augment the defense characteristics
offered by the inundated areas.
The most favorable lines of defense across the base of the COTENTIN
Peninsula would be:
(1) Valley of the DOUVE River, PRAIRIES MARECAGEUSES, to nearest west
coast or via valley of River OLLARDE.
(2) Valley of the DOUVE River, PRAIRIES MARECAGEUSES DE GORGES, to nearest
west coast via the valley of the River AY.
In general the road net is adequate but will require some reconstruction
and maintenance.
The seizure of the exits from the beaches and high ground back
of them is mandatory for the successful and early deployment of beach
landing troops.
The seizure of the crossings of the River DOUVE is mandatory,
to prevent the enemy from crossing the inundated area from the South.
The many approaches from the North make for easy access to the area
from the communications center at VALOGNES.