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Cat bag – Flooding of the IJzervlakte (Nieuwpoort, Belgium)

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General information about Kattesas - IJzervlakte flooding

This section is about the Kattesas and the flooding of the IJzervlakte. The Kattesas was also called the "Spanish lock"because the hydraulic engineering work dated from, or was reinforced during, the period of Spanish rule in the Southern Netherlands in the 16th and 17th centuries. Sometimes you will also see the name'Oud Veurnesas'. It was via this small spillway ( barely 5.6 meters wide) that attempts were made to flood the IJzervlakte during the First World War.

After trying this twice via the Kattesas (and finding that the flow rate there was too low), it was finally decided to also use the large locks at the lock complex of "the Ganzenpoot' lock complex, more specifically the Overlaat van de Noordvaart (Veurne-Ambacht). It was Karel Cogge, a supervisor at the Noordwatering Veurne (NWV), who came up with this idea. The military authorities first tried to use the Kattesas for safety reasons, but ultimately had to implement Cogge's plan. On October 29, 1914, the plain between the Yser on one side and the Nieuwpoort-Diksmuide railway line on the other was completely flooded. We are talking about a strip of land about 1 to 3 km wide and 15 km long, roughly 30 km². The water was 30 to 60 cm deep. This prevented the German invaders from advancing any further. Throughout World War I, the Nieuwpoort-Diksmuide line was held, partly thanks to this ingenious plan of flooding the area.

At theGanzenpootlock complex, more specifically between the Veurnesluis lock and the Overlaat van de Noordvaart, you can still see a monument commemorating this historic event.

Karel Cogge was supervisor of water management/Noordwatering in Veurne. His statue stands at the St. Walburga Church in Veurne (see photos below in the photo section).

Of course, he did not open all the sluices himself. The Belgian engineering troops did this under the command of reserve captain Robert Thys. This soldier was stationed in the Dumont district in De Panne (in Villa "Val d'Ante, " now called Villa "Zonneweelde" ). Some heroes from his company, namely Hendrik Geeraert, a ship's boy from Nieuwpoort, Frans Cop, and Kamiel Van Belle, were quartered in the villa right next door, Villa "La Roche." Both Cogge and Geeraert are still regarded as heroes today, one in Veurne, the other in Nieuwpoort. 😉

Chronological sequence:
October 21, 1914: Hendrik Geeraert opens the Sas van de Kreek lock in Nieuwendamme at night and high tide
October 26, 1914, 2:30 a.m.: Kattesas is opened (Cogge's "Plan B"), at 3:45 a.m. the lock gates close unexpectedly! Kattesas was chosen because the locks of the Ganzenpoot were within range of German artillery.
October 27, 1914: second attempt via Kattesas (lock gates were held open with chains)
October 28, 1914: Kattesas continues to be used (twice a day – at high tide). However, the IJzervlakte did not fill with water quickly enough.
October 29, 1914: Hendrik Geeraert finally opened the locks of Veurne-Ambacht (De Ganzenpoot lock complex) – this was Cogge's "Plan A." According to some sources, however, this alternative plan may have come from Geeraert. 😉 Anyway, the IJzervlakte was now filling up faster.
October 30, 1914: the IJzervlakte has already flooded about 4 to 5 km inland
November 1, 1914: the IJzervlakte is flooded.
The decisions about which sluice could be closed were always made by the military authorities. While Cogge was the originator of the plan, Geeraert was the executor (actually one of the executors).

In recognition of his efforts, Hendrik Geeraert was depicted on the 1,000 BEF banknotes after the war.

Did you know that... the technique of flooding land to keep the enemy at bay did not actually originate with Karel Cogge (nor with Hendrik Geeraert)? Flooding land is a centuries-old, tried-and-tested military tactic to hinder the enemy's advance. There are examples that date back several centuries: just think of the Old Dutch Waterline (17th century). It was used against France, among others (Calamitous Year 1672). Large parts of Holland were deliberately flooded at that time. At that time, the water level was controlled with an accuracy of a few centimeters. During the Eighty Years' War, the Dutch also breached the dikes to flood large areas of land. So 'flooding' as a tactic to keep the enemy at bay certainly did not originate with Karel Cogge. That is a misconception among the general population. He did, however, have the local knowledge to flood the IJzervlakte quickly and effectively.

Visitor tips Kattesas - IJzervlakte floodplain

General tips:
1) if you are looking for other nearby attractions, consult our Tourist map of Top.Vlaanderen.
2) You can consult our overview lists: by category ( e.g. timeline, size, ...) or by region
3) You can also always consult tourist services: see our overview of tourist services

Tip 1: There is the Cogge-Geeraert cycle route , which is about 41 km long and highlights the flooding of the Yser plain. There is also a 75 km long car route called "Ijzerfront. "

Tip 2: If you want to see the railway embankment that served as a dike, head to the reconstructed Belgian Fortification on the Frontzate.

Geographical information

Address: Handelskaai 21, Nieuwpoort, West Flanders, Belgium
Geographic coordinates:
Google Maps: Latitude = 51.1356077 – Longitude = 2.7440369
Open Street Maps: Latitude = 51.135541 – Longitude = 2.744162
Altitude h = 1 m
Indication of Kattesas - IJzervlakte flooding on:
Tourist map of Top.VlaanderenGoogle MapsOpenStreetMap.
Route to Kattesas - IJzervlakte flooding: Route via Google Maps

Meteo

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Nieuwpoort, BE
11:11 p.m., 07/03/2026
weather icon 7°C
Low: High:
dense fog
Sunrise 07:21
Sunset 18:39
Humidity 100 %
Pressure 1025 mb
Wind 13 Km/h NE
Wind Gust 0 Km/h
UV Index 0
Precipitation 0 mm
Clouds 100%
Rain Chance 0%
Visibility 0 km
Day Condition Temperature Precipitation Rain Chance Wind Humidity Pressure
Tomorrow 22:00
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7° | 8°°C 0 mm 0% 10 Km/h 97 % 1024 mb
Mon Mar 26 10:00 p.m.
weather icon light rain
8° | 17°°C 0.2 mm 20% 12 Km/h 90 % 1021 mb
Tue Mar 26 10:00 p.m.
weather icon light rain
8° | 13°°C 0.2 mm 20% 12 Km/h 93 % 1020 mb
Wed, Mar 26 10:00 p.m.
weather icon light rain
6° | 11°°C 1 mm 100% 34 Km/h 90 % 1019 mb
Thu Mar 26 10:00 p.m.
weather icon cloudy
5° | 12°°C 0 mm 0% 33 Km/h 92 % 1020 mb
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Hour Condition Temperature Precipitation Rain Chance Wind Humidity Pressure
Tomorrow 01:00
weather icon cloudy
8° | 8°°C 0 mm 0% 10 Km/h 97 % 1024 mb
Tomorrow 04:00
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7° | 8°°C 0 mm 0% 9 Km/h 96 % 1023 mb
Tomorrow 07:00
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6° | 6°°C 0 mm 0% 8 Km/h 93 % 1023 mb
Tomorrow 10:00
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9° | 9°°C 0 mm 0% 9 Km/h 71 % 1023 mb
Tomorrow 13:00
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16° | 16°°C 0 mm 0% 8 Km/h 51 % 1023 mb
Tomorrow 16:00
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17° | 17°°C 0 mm 0% 7 Km/h 50 % 1021 mb
Tomorrow 19:00
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13° | 13°°C 0 mm 0% 5 Km/h 68 % 1021 mb
Tomorrow 22:00
weather icon very light cloud cover
11° | 11°°C 0 mm 0% 7 Km/h 79 % 1021 mb
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Tide predictions

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    Internet information from and about Kattesas - Flooding of the IJzervlakte

    Wikipedia information on:
    - the Flooding of the IJssel plain (EN)
    - Inundation (EN - AND - THE)
    - the IJzer watercourse (EN - FR - AND)
    - the Battle of the Yser (EN - FR - AND)
    - the hero Karel Cogge (EN - FR)

    Nieuwpoort Tourist Office “Visit Nieuwpoort”:
    website - Facebook - Instagram
    Tourism “The Coast” (Westtoer)
    Website - Facebook - Instagram - YouTube

    Our photos about Kattesas - Flooding of the IJzervlakte

    Photos of the Cat House (February 3, 2026)

    Photos of the Overlaat van de Noordvaart / Veurne-Ambacht (February 3-4, 2026)

    This spillway is located at theGanzenpootlock complex, right next to the Veurnesluis lock. At the end of October 1914, it was possible to dam up a sufficient flow of water here in the direction of the Yser plain.

    Photos of Karel Cogge's statue in Veurne (February 2, 2026)

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