The Environment Agency's National Incident Recording System (NIRS) show that there were 33 sewage related discharges into the Hampshire Avon and its tributaries in 2005 and 21 such discharges so far in 2006. The following table summarises these incidents by category and river catchment.
River Category 2005 20061 Hampshire Avon2 Category 1 0 0 Category 2 2 1 Category 3 or 4 13 9 River Nadder Category 1 0 0 Category 2 0 0 Category 3 or 4 4 2 River Ebble Category 1 0 0 Category 2 0 0 Category 3 or 4 1 0 River Wylye Category 1 0 0 Category 2 0 1 Category 3 or 4 12 3 River Bourne Category 1 0 0 Category 2 0 0 Category 3 or 4 1 5 Total Category 1 0 0 Category 2 2 2 Category 3 or 4 31 19 1 To 22 November 2006. 2 Source to Christchurch.
Each incident was investigated to establish the cause and to quantify the impact. For Category 1 and 2 incidents (those with the greatest impact) the Environment Agency also gather evidence which may be used to support subsequent enforcement action. In addition, the Environment Agency would ensure that visible evidence of sewage pollution is removed from the river and that the polluter takes action to prevent a reoccurrence of the incident.