It has as its catchment area the Vale of White Horse, a low-lying and wide valley in south Oxfordshire, and flows into the River Thames, at Abingdon on the reach above Culham Lock.

[citation needed] From Little Coxwell, the Ock runs around Longcot and flows past Stanford in the Vale, where it is about 10 feet (3 m) wide.

Thence it runs past Charney Bassett, Lyford, Garford and Marcham Mill, before losing its identity and its waters to the Thames at Abingdon by the old Hygienic Laundry building.

[citation needed] The soils through which the River Ock flows are the Jurassic sedimentary series (Greensands, Gault, Kimmeridge Clay and corallian limestone), while some of its tributaries arise in chalk springs.

[citation needed] Although normally placid, the Ock can flood low-lying areas of south Abingdon after persistent heavy rainfall; this recently occurred in April 2023,[1] January 2024,[2] September 2024[3] and November 2024.