To mark World Rivers Day (22nd September) we are focussing on chalk streams (thanks in part to being inspired by a recent Instagram post from the Holkham estate ).
Chalk streams are rare and valuable habitats with a constant flow of water from underground chalk aquifers making them pure, clean, constant and a perfect source of clean water. According the WWF there are 200 worldwide and 85% of these streams are found in England, mainly in the southern regions.
They are a good source of water for drinking, agriculture and industries such as angling and are ideal locations for lots of wildlife. However, many are not in a healthy state and have been degraded due to drainage improvements for meadows, pond creation for landscaping, man-made embankments for water level control and more.
Restoring these waterways will be vital as chalk streams provide benefits to people’s well-being, and the environment by increasing biodiversity, providing clean and health drinking sources, and reducing flood risk by reconnecting to the floodplain.
The Hampshire Avon is the England’s most iconic and quintessential chalk stream. As part of a project led by DEFRA and the Environment Agency , restoration work to the river Avon and its tributaries has been underway over the last 20 years.
Many of the rivers were modified for mills and water meadows with flood defences, land drainage, agricultural intensification and urban development impacting the rivers since the 1940’s. River dredging for drainage had disconnected the river from its floodplain, trapping sediment and reducing water quality and migration routes for fish. This caused poor water quality and disconnected habitats and wetlands.
Bluesky’s aerial images taken of Norton Bavant between 2014 and 2023 perfectly illustrate the re-meandering of a straightened mill leat. A new 200m channel in a more natural area was created, bypassing the former mill and allowing a natural reconnection to the floodplain. This project was undertaken between 2011 – 2017. Old aerial images suggest the Norton Bavant channel was created after 2014. Other restoration including removing raised embankments, reprofiling banks, redistributing gravel, and new channel creation. By 2017 50km of chalk stream had been improved and over 10ha of wetland habitat created.
2014 - 2017: A new 200m channel in a more natural area is created
2017 - 2023: Wetlands and habitats created, water quality improved, flood risk reduced
2014 - 2023: 10 year progression
Bluesky International Ltd, 2024
+44 (0) 1530 518 518
