Monday, 15 December 2008

The River Kennet from source to confluence

Catchment

The River Kennet rises in the prehistoric landscape of rural Wiltshire, and flows for around 70km (44 miles) east into Berkshire until it joins the Thames in Reading. Drawing from a catchment area of nearly 1200km2 (which incorporates its own tributaries the Og, Dun (and the Shalbourne), Lambourn, Enbourne, and the Foudry Brook) the Kennet is said to contribute up to half the flow of the Thames during some summer periods. The River Kennet also supports a 10km secondary channel called the Holy Brook which flows from Arrowhead, near Theale, into Reading.

The reaches of the River Kennet


The River Kennet is divided into three reaches by the Environment Agency [1], which are defined as follows.

- The upper reach from the source to Eddington Bridge in Hungerford

- The middle reach from Eddington Bridge to the A34 Newbury bypass

- The lower reach from the A34 bypass to the confluence with the Thames in Reading.


These distinctions have been made on the basis of the types of fishing that predominate in each section, but, when slightly amended, they serve to conveniently divide the river according to its paddling potential. An overview of each reach is provided in separate posts.

Environmental characteristics

Although the River Kennet is classified as a 'chalk stream' river [2], which is what makes it so ideal for trout and potentially interesting to salmon, it faces a number of environmental issues of concern including over-abstraction by water companies, raised levels of turbidity (particularly in its lower reach where its route is substantially canalised leading to a high level of motorised river traffic, as well as the influence of the urban environments of Marlborough, Hungerford, Newbury, and Reading), and the introduction of non-native species of flora and fauna.

Between Marlborough and Woolhampton the River Kennet is a notified Site of Special Scientific Interest (SSSI) [3].

In an attempt to help reintroduce salmon to the full length of the Kennet a series of fish ladders have been installed at 16 mills, sluices and weirs on the lower and middle reaches of the river [4]. Unfortunately, the spending on these projects (for which success now appears to hang in the balance [5]) wasn't matched by funding to provide similar access for paddlers at these bars on the river.


Trout in a Kennet tributary (the Dun in Hungerford in this instance).

Maps

In driving to and walking along the River Kennet I've used the following printed map resources.

- Ordnance Survey Explorer 157, Marlborough & Savernake Forest - covers from the highest upstream sources to just past Ramsbury.

- Ordnance Survey Landranger 174, Newbury and Wantage - Mildenhall to Woolhampton.

- Geo Projects Kennet and Avon Canal, 5th Edition - clearly distinguishes the sections of the Kennet that have been canalised below Newbury.

For online ease the Ordnance Survey Get-a-map service provided quick confirmation of the standardised six digit location references used in this blog.

For greater detail the following council web sites provide excellent mapping information.

- Kennet District Council's online map online map has been incorporated into the Wiltshire CC site, and covers from the sources down to Kintbury.

- West Berkshire Council's online map includes Hungerford to the edge of Reading i.e. all the sensible bits for paddling.

[1] Taken from the Environment Agency's Fisheries Action Plan for the Kennet and Pang, which, although removed from their website, was updated in 2008, and is now available on request.
[2] See the Wikipedia article at http://en.wikipedia.org/wiki/Chalk_stream. See also http://publications.environment-agency.gov.uk/pdf/GETH0404BHXH-e-e.pdf?lang=_e
[3] English Nature's citation for this SSSI can be found at http://www.english-nature.org.uk/citation/citation_photo/2000164.pdf
[4] See http://www.millennium.gov.uk/cgi-site/awards.cgi?action=detail&id=135&t=2
[5] See http://residents-association.com/tdt40/upstream_struggle.php