Hydrology
Whilst chalk underlies much of the River Loddon's catchment area, it only appears at the surface at either end of the river, near Wargrave and Basingstoke. For the rest of its course the chalk lies beneath the Reading Beds and London Clay. The terrace gravels of the Loddon valley have been extracted in a number of places, including the lakes within Dinton Pastures Country Park.
The catchment area of the River Loddon encompasses urban populations in Basingstoke and eastern Reading, whilst the urban areas of Aldershot, Fleet, Camberley and Farnborough all lie within the catchment area of the tributary River Blackwater. As a consequence the Loddon receives treated sewage effluent at nine locations, one just downstream of Basingstoke, a second at Wargrave, and seven indirectly via the Blackwater.
Read more about this topic: River Loddon