Chalk streams are rivers which arise from chalk reservoirs deep beneath the surface and flow thought chalk land.
They are almost, but not entirely, confined to England and the majority are in Hampshire, Wiltshire and Dorset. The Rivers Test and Itchen are possibly the most famous of the English chalk streams. Our Anton is a tributary of the Test.
Chalk is a very porous rock so rain falling on the chalk downlands filters down through the strata until it hits less permeable rock at which point it flows horizontally until it emerges into lower ground as springs. There may be many months before water falling on the hill emerges again from the ground. The Anton is born in an unassuming rivulet in an Andover housing estate and flows through the town gathering other streams as it goes. The water that emerges has fallen over the chalk hills to the north.
Because of its journey filtering through the chalk, the water of a chalk stream tends to be clear, pure and rich in minerals. It maintains a fairly constant temperature through the year. The chalk streams tend to be wide and shallow with a flint and gravel bed. The chalk stream environment is very favourable to the growth of abundant weed and the weed in turn supports a wide variety of insect life. The growth of weed tends to be carefully managed by river keepers who are skilled in cutting the weed when the growth is such as to clog the river course and cause flooding. Cutting river weed is hard work and involves wading in the stream and wielding a long scythe. By agreement weed cutting is restricted to certain weeks in the summer.
The clear pure water and abundant insect life provides an excellent setting for populations of brown trout and grayling. The grayling is a wild fish and so are many of the trout, but in order to satisfy the desires of fishermen most river owners introduce fresh stocks of brown trout during the fishing season to maintain the population.
The clear pure water and abundant insect life provides an excellent setting for populations of brown trout and grayling.
Over recent years the chalk stream environment has come under threat from a number of directions. The growing population of the upper Test valley means there is more water extraction which has reduced summer flows. There is also more waste that needs to be disposed of in rivers. Occasionally unthinking people dispose of poisonous chemicals into drains which lead directly into the river and kill animals and plants. There are also the diverse threats of climate change, air pollution and building. Some speak of the chalk streams as our equivalent of the rain forests. They are an important and vulnerable natural resource which we should fight hard to protect for the benefit of future generations.
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