Location 5: Koudhoornse Sluis

A house was built around 1879 for lock-keeper Gerrit Eimbert Westhof (1848–1930), who succeeded his father, next to the Koehoorn Lock, which was still made of wood at the time. The house is situated on a prominent rise in the landscape. In 1880, the lock was replaced by a brick-built structure, which was thereafter known as the Koudhoornse lock. 

During construction in 1880, a fire broke out at the nearby De Halve Maan paper mill (now Holland Colours). Thanks to the prompt action of the workers at the lock, who kept the factory wet, further damage was prevented. The damage was limited to two burnt-out houses adjoining the factory.  

Here at the Koudhoornse Sluis there is a row of six lime trees (there were originally seven). It seems that there used to be a row of seven lime trees at every lock along the Apeldoorn Canal, to provide protection against the sun, wind and lightning. The trees were probably planted shortly after the lock was renovated in 1881.

The Koudhoorn Lock is situated in the northern section of the Apeldoorn Canal in the municipality of Apeldoorn. The canal was constructed using private capital, including funds from King William I. Work on the canal and the construction of the locks and bridges began in 1825. On 13 April 1829, the canal was officially opened and given the name Grift Canal. The lock, which was originally made of wood and named the Koehoorn Lock, was 22 metres long and 4.30 metres wide at the time, with a sill depth at the lower head of KP -1.42 m.  

In 1873, work began on widening the Grift Canal – specifically the Apeldoorn–Hattem section, which had already been in existence for almost half a century. The locks were also renovated as part of this project. The canal had to be made accessible to vessels 30 metres long and 5.90 metres wide. The Koudhoorn lock was therefore replaced in 1880 by a masonry lock, which came into use in 1881. During construction, shipping had to continue, so the canal was temporarily diverted and re-excavated behind the new lock-keeper’s house.  

In February 2010, it was decided that the Koudhoorn lock would be restored. The renovated lock was reopened in 2011.

See also: Opening of the Apeldoorn Canal 

A paper mill had been situated on the canal, halfway between Apeldoorn and Vaassen, since 1857. In 1880, Klaas Schenk, an entrepreneur from North Holland, bought the factory and renamed it ‘De Halve Maan mechanical paper mill’, after the De Halve Maan windmill that stood on the site. 
In Apeldoorn, he relied entirely on steam power, and the windmill was demolished around 1900.  

The company specialised in wrapping paper and also ran a sack-making workshop for a number of years. When Schenk took over the business, there were around ten people from Apeldoorn working at the factory. They were generally locals, as there were hardly any means of transport. Business at the paper mill was thriving. Around 1900, there were twenty staff members, and by 1935 this number had risen to seventy. This progress was also evident from the fact that, in 1938, permission was granted to construct a loading and unloading bay on the banks of the canal. Schenk gained prestige and became a well-known name in Apeldoorn.

In 1976, the company went into liquidation and the employees were made redundant. Following a series of takeovers, the factory premises eventually came into the hands of the pigment manufacturer Holland Colours Apeldoorn in 1979.

See also: Memories of Apeldoorn on the Map

The pedunculate oak: a source of life 

The pedunculate oaks along the water’s edge look magnificent with their gnarled branches and fulfil many different functions within the ecosystem. Their broad crowns are teeming with life. Titmice, jays and woodpeckers find food, shelter and vantage points there. Insects buzz amongst the leaves, which in turn attract other animals. The oak is a living platform where countless species come together. 

On the ground beneath the tree lie acorns, which are picked up by squirrels, mice and jays. Some are eaten, whilst others are hidden away and forgotten. From those forgotten acorns, young trees grow, further strengthening the riverbank and creating new habitats for animals. 

Deeper underground, the pedunculate oak works in partnership with a network of fungi. Through these fungal hyphae, it exchanges nutrients and helps to keep the soil healthy. In this way, it supports not only itself, but also the plants around it. 

The pedunculate oak by the canal is no ordinary tree. It is an anchor in the landscape, a source of sustenance for wildlife and a silent guardian of the bank.  

The reed warbler: a small bird of great value 

The reed warbler lives in the reeds. It is a modest songbird, no bigger than a hand, but with a voice that can fill the whole reed bed. Every spring it returns from Africa after a long journey. As soon as it sees the reeds, it knows: this is its home. Among the stalks, it builds an intricate nest, suspended like a cradle, carefully woven into the reeds. There, the female lays her eggs, safely hidden from predators. The little reed warbler does not live alone. The reeds provide a habitat for frogs, dragonflies, fish and other reed birds.  

The reed warbler is well hidden amongst the reeds and finds plenty of food in the form of insects. If the reeds are cut too often, this beautiful species will disappear from the area. That is why the presence of the reed warbler is a good indicator for the management of reed beds.  

The numbers of reed warblers increased sharply in the 1970s, although this was not for a positive reason. The agricultural sector was using large quantities of fertilisers, which also ended up in surface waters. As a result, the reeds began to grow incredibly well. This made for a perfect habitat for this reed-dwelling bird. Although the reed warbler is common across large parts of the Netherlands, it is still an emerging species in Apeldoorn and the surrounding area.