Baldon Brook


The Baldon Brook rises in Garsington and flows southwest under the B480 before turning sharply south east to join the River Thame downstream of Chiselhampton. The land-use is mainly arable with some pasture near its source.

In 2015, the Environment Agency classified the Baldon Brook as “moderate”. This classification is based on multiple factors, but the main drivers of the moderate status are phosphate and macrophytes, all other measured factors are currently ranked as “high” or “good”. It is not surprising that phosphate is not good in this catchment due to the intensity of agricultural land around the brook. Previously, in 2014, this catchment area was defined as good status, but at the time both phosphates and macrophytes had not been surveyed in the catchment, therefore their status was not incorporated into the 2014 ranking. The 2027 objective for the Baldon Brook is “good”, including phosphate levels. We hope to work with our partners to reach this objective.

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.baldon-brook-small-waters



Baseline surveys in 2013 showed that phosphate and nitrate levels in this catchment were incredibly high, this was a one off survey and we are keen to repeat this to see how the situation may have changed.

We currently have no volunteers regularly monitoring in this area. You can find out more about our volunteer monitoring and how you could get involved in monitoring yourself here.

Other Groups

There are currently no groups that are working specifically on the Baldon Brook. If you would like to get involved by starting a local group in your area, then please get in touch.