The uppermost reaches of the Thame trace the northern edge of Aylesbury from Watermead Lake to Quarrendon, where the river picks up water from its first main tributary, Hardwick Brook. The brook is often mistaken for the source of the Thame, but that is, in fact, close to Marsworth, northwest of Aylesbury. Hardwick Brook is the most northerly waterway in the Thame catchment running from Stewkley, past Cublington and Hardwick to the confluence. On the way, it is fed by two small brooks from Creslow and Dunton and also by output from the Stewkley sewage treatment works.
The land it flows through is mostly flat farmland, both arable and livestock, although new housing developments such as at Berryfields are encroaching on the southern part. The stream is slow-flowing at most times, although it can flood, and there are warning signs. The stream bed has a lot of reeds and other vegetation growing in it such that the water can hardly be seen during dry summer spells (such as in the photograph above).
Further survey work needs to be done in order to fully understand the state of the stream and how land-use may impact the river.
In 2015, the Environment Agency classified the Brook as “moderate”, meeting its 2015 target. This classification was given due to multiple factors, but was mainly due to phosphate being classed as “poor” and macrophytes being surveyed as “moderate”. All other measured factors were classed as either “good” or “high” in the catchment. The STW at the top of the catchment will undoubtedly have an impact on the phosphate readings here, and currently there is a targeted improvement to “moderate” set to be reached by 2021, which we hope will be improved to at least “good” by 2027.
You can find out more about the classification of rivers in our catchment by using the Environment Agency’s Catchment Data Explorer.
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.
We currently do not have any monitoring happening in this area. It would be great to extend our volunteer monitoring, particularly riverfly and water quality monitoring, to find out if there are some areas that should be celebrated or places that need improvement. You can find out more about our volunteer monitoring and how you could get involved in monitoring yourself here.
There are currently no groups that are working specifically on these Brooks. If you would like to get involved by starting a local group in your area, then please get in touch.