Rising at Stourhead Lakes in South Wiltshire, the upper catchment of the Stour is dominated by farming and steep, clay valleys that create flashy streams that flood suddenly after rainfall. The river weaves through the Blackmore Vale, a scenic landscape at the foot of Dorset's chalk downland which marks the north of the Dorset Area of Outstanding Natural Beauty (AONB).
The Middle Stour then feeds through a porous chalk band which produces winterbournes, chalk streams that typically dry in the summer when the water table drops below their groundwater springs, such as the North Winterbourne and the Tarrant.
The river then flows down to newer clays, sands and gravels in the more populous, urbanised area towards the south coast. Passing through Wimborne and the wider Bournemouth area, the Stour is joined by the Allen and Moors tributaries before draining into Christchurch Harbour alongside the Hampshire Avon.
The Stour catchment has far fewer protected or designated sites than its neighbouring catchments, Poole Harbour and the Hampshire Avon, although all three are home to a significant portion of internationally rare chalk stream habitats. In the past, this has resulted in the Stour gaining something of a ‘Cinderella’ status - a lower priority, receiving less funding despite experiencing many of the same issues.
Stour Catchment Partnership works collaboratively to ensure that the Stour receives its fair share of resources to restore natural river functions throughout the catchment.