Human occupation has influenced the river over the centuries. Major settlements now associated with the river valley are Fakenham, Lenwade, Taverham, Drayton, Costessey, Hellesdon and Norwich. Dereham and Reepham are within the wider catchment area. There is also a string of small villages lying along the edge of the valley floor. These are virtually all associated with convenient crossing points of the river. Apart from the growth in size of Fakenham, the outer parishes west of Norwich and the villages of Hempton and Lyng, this pattern of settlement has changed little since the 19th century.

Early human influences.

During the early post-glacial period temperatures rose and the Wensum would, typically, have been a slow-flowing river fringed by reed swamp. The slopes and plateau would have been covered by woodland. Deposits of charcoal and Mesolithic flints have been found at Spong Hill on the Whitewater, near North Elmham. These indicate that tree clearance may have begun from the Mesolithic period.

By the late Iron Age intensively-farmed landscapes would have been established in some areas. During the Roman occupation large areas of forest were cleared and inroads were made into the boulder clay region of central Norfolk. At this time the Wensum was crossed by four main routes at Hempton, South Raynham, an area west of Norwich and, the most significant, at Billingford, where there was a large Roman settlement and a fort south of the crossing.

Woodland clearance continued through later centuries with substantial Saxon settlements found at Spong Hill in North Elmham and at Norwich. During the Medieval period, cultivation continued along the valley sides and plateau lands and the valley floor was used for grazing and pasture.

In the 17^th, 18^th and 19^th centuries, substantial areas of parkland were laid out. The largest and most notable of these were South Raynham in the upper Wensum and Costessey Park (no longer extant) on the Tud. These designed landscapes had a considerable impact on the river as it may have been dammed for aesthetic reasons. For example, at Costessey on the Tud, the 'Longwater' was formed through Costessey Park, presumably to provide a more impressive vista and perhaps to provide boating facilities.

There is also evidence of considerable industrial activity during this time, which made use of the abundant water supply. 19^th century maps show that the river was managed in a much greater way than it is today. Indeed, there were plans to make the Wensum navigable upstream of Norwich as far as Dereham and Fakenham. However, this work was never carried out, probably because the Great Eastern Railway and the Midland & Great Northern Railway were built in the 1880s. The lines of these railways followed much of the course of the Rivers Wensum and Whitewater.

Norwich was originally a centre for the tanning industry but the pollution of streams and the stench of the tan pits made this an unpopular activity in towns and it was forced into more rural areas. The two main essentials for tanning were a supply of bark, usually oak, and fresh water for washing the hides. The pollution map of 1850, produced for an enquiry into the sanitary conditions of Norwich, showed seven fellmongers (tanners and dealers in animal skins) on the river in Heigham upstream of Norwich, where they had relocated on open meadowland out of the City. Another major tanning works was located at Whitwell, which did not shut down until the end of the 19th century.