Peter Hutchings from Hampshire and Isle of Wight Wildlife Trust tells us why the chalk streams of Hampshire are so important.

For many, the term chalk stream conjures idyllic images of the iconic River Itchen with crystal clear water flowing gently through grassy meadows, a patchwork riverbed of emerald green water weed and mottled dark gravels, a bankside fringed with spikes of purple loosestrife, lazy fluttering damselflies and an azure flash of a kingfisher.

Apart from the well know Rivers Test and Avon, there are several other chalk streams in Hampshire which are just as stunning, just as important, but frequently overlooked.

Often known as the “Cinderella rivers”, the Meon in the south, and the Loddon with its tributaries the Lyde, the Whitewater and the Hart in the north-east, are essential to the lives of thousands of people and a wealth of wildlife.

These rivers supply our water, take away our waste, offer places for recreation, and are home to a vast array of plants and animals, both aquatic and terrestrial.

The Loddon, Lyde and Whitewater are all recognised as Sites of Importance for Nature Conservation (SINCs), and the Meon, also a SINC, is the focus of a partnership project to conserve the river and its valley.

Over hundreds of years we have slowly changed our chalk streams for navigation, transport, agriculture and milling.

We have dredged, engineered and altered them for our benefit and as our towns have grown, we have taken ever more water.

Today, these rivers struggle against many threats.

In heavy rain, water gushes off roofs and roads and sewers cannot cope so water laden with town pollutants and raw sewage sweeps into the watercourses.

Modern farming practices mean fertilizers, organic manures and pesticides can all too easily run off into rivers, and heavy machinery can compact and damage the soil increasing the likelihood of it being eroded from fields and washed into watercourses.

Climate change scenarios predicate yet more problems for these chalk streams.

All these troubles are compounded by people taking too much water for household use, irrigation and manufacturing. Alien species, which are not native to the UK, are an increasing worry.

Himalyan balsam is spreading virtually unchecked along riverbanks growing rapidly, spreading easily and out-competing other vegetation.

When it dies back in winter, it leaves large areas of bare ground that erodes easily.

Wild American mink, descended from fur farm escapees, are a major cause in the continuing decline of water voles. Signal crayfish, introduced to the UK in the 1970s as a food delicacy, carry crayfish plague, which has decimated populations of our native white-clawed crayfish. However, these problems are not beyond our control.

The Hampshire and Isle of Wight Wildlife Trust is working with government agencies, the water companies, farmers, fishing clubs and landowners to ensure our rivers are able to meet our needs but are still healthy, vibrant places for wildlife and people.