Lower River Thame


Cuddesdon Mill

Cuddesdon Mill (doug-kennedy.com)

The lower section of the River Thame runs from the town of Thame to its confluence with the River Thames just south of Dorchester-on-Thames: a distance of about 52km. From Thame town, the river flows broadly west past the villages of Shabbington and Ickford to Waterstock. It then turns to the south passing under the M40 and A40 junction and services at Wheatley, past Cuddesdon Mill and Chiselhampton, (where it is joined by the Chalgrove) before continuing on to Dorchester.


The Thame at the confluence

The Thame at its confluence with the Thames (doug-kennedy.com)

The Thame Valley broadens out from Thame town and continues to widen, along the river, on its passage through the rural Oxfordshire countryside. The river skirts a number of attractive villages along its route, but it is bordered by fields over its entire length, apart from a few small copses or woods. There is a lot of vegetation cloaking the banks which often hides the water from view, but which gives plenty of cover for wildlife to hide in: the monthly wetland bird (WeBS) survey that we are carrying out has found over 40 species of birds in addition to the farmland terrestrial species!

Fish are present and there are facilities for anglers at several points on the lower Thame, but more work is needed to understand their exact status. At all but the highest flows, fish cannot migrate up the River Thame from the Thames because of the weir at Dorchester (at the top of the Hurst Water Meadow).

Stadhampton STW 2-001

Five sewage treatment works feed directly into the lower Thame and others feed into several of its tributaries.

In 2015 the Environment Agency classified the Lower Thame as “moderate”, meeting its 2015 target and improving on its 2009 classification of “poor”. This “moderate” classification is based on multiple factors including fish, macrophytes, and invertebrates. The lower Thame has only one factor listed as “moderate”, phosphate, with the remaining variables all classified as “good” or “high” (under Water Framework Directive). Currently there is no data listed for fish, but we are aware that there are surveys going on at the moment and we hope that these will provide us with a good picture of the river’s health. We expect that some problems will be uncovered though, as unfortunately fish-passage along the river is very difficult due to a number of mills and other blockages. There are no 2027 targets available at the moment, but with careful planning and work, this section of the Thame could reach “good” status.

You can find out more about the classification of rivers in our catchment by using the Environment Agency’s Catchment Data Explorer.


Small Waters

The river isn’t the only water that we are concerned with. There are multiple small waters including ponds, ditches and steams. All of which are highlighted on the map below.lower-thame-small-waters



This is the part of the river that we probably know most about. We have worked extensively in this section, carried out walkovers and completed a number of projects. The Environment Agency also monitor the main channel, fish surveys have been happening across its length this summer (2016).

Our summer intern, Ellen Robson, is also currently writing her dissertation project on the main River Thame, she surveyed 25 sites across August and we will be hearing what she learned at the end of this year.

Our volunteers also work hard to monitor the quality of the water across much of the rivers length, whilst the bird surveyors carry out monitoring once a month. We would love to increase the amount of data we receive so take a look at how you can get involved here.

Other Groups

Hurst Water Meadow Trust look after much of the river and its riparian land around Dorchester, holding regular work parties and allowing visits from schools and the general public. There is also other interest on the main river coming from anglers, local parish councils and schools.

If you have information on others who might be looking after the lower river Thame or would like to get involved in joining or starting a local group in your area, then please get in touch.

Thame at Dorchester. Credit: Alec Powell

Thame at Dorchester. Credit: Alec Powell

Thame at Cuddesdon. Credit: Andy Coates

Thame at Cuddesdon. Credit: Andy Coates

Thame at Cuddesdon. Credit: Andy Coates

Thame at Cuddesdon. Credit: Andy Coates

This selection of videos has come from a camera trap placed on Waterstock Mill by Henry Mainsty. These videos give us a great picture of the amazing wildlife that we are working hard to protect.