The Freshwater Habitats Trust (FHT) was appointed as the catchment host for the Ock in 2013 and is leading the development of the catchment partnership with the support of the Environment Agency.
The Ock rises in Little Coxwell (SU 280935) and flows eastward for 38km to join the Thames at Abindgon (SU496967). The Ock catchment is characterised by clay, but is bordered to the north by limestone and sandstone which form a small escarpment, and to the south by chalk which forms an upland ridge (the Ridgeway) which rises to a maximum of 240m at White Horse Hill. Spread across the catchment are a range of springs, headwaters, ponds, small lakes, and the larger streams and rivers. The catchment is also well-known for its fens, and wet meadows, all of which are affected by the quality and quantity of the water in the environment.
The Ock receives contributions from a number of spring fed tributaries including the Letcombe and Ginge brooks. Other major tributaries of the Ock are: Childrey, Cherbury, Frilford, Marcham, Sandford, Land, Stutfield and Cow Common brooks.
In addition to the defined catchment of the Ock itself, the Ock Catchment Partnership also encompasses the section of the Thames running through Oxford and Abingdon from the Evenlode confluence to the Thame confluence. The major tributaries contributing directly to the Thames in this section are the Ginge and Mill brooks (Drayton), the Moor and Ladygrove Ditch (Didcot) and the Northfield Brook (Oxford).
The 2013 water quality data from the Environment Agency suggests that water quality across the different streams and brooks is generally “Moderate” or “Poor”.
Factors influencing the water environment in the Ock catchment are likely to be rural and urban diffuse pollution, waste water discharges, road run-off, loss of habitat and biodiversity and invasive non-native species. Flood management is both currently in the spotlight and also a longer-term issue that needs careful deliberation and planning.