Mill Brook is the name given to the stream which until recently flowed from Blewbury through South Moreton and Hithercroft to Wallingford. The Brook, at different points known as Mill Brook, Padsey Brook, Mill Ditch and Mackney Brook, until 1972 flowed through the western outskirts of Wallingford, to enter the Thames near St Leonard's church. Much of the Brook's course and that of Bradfords Brook has been artificial since 1968 when the watercourses through Wallingford were substantially modified and re-routed by the then Thames Conservancy and the Borough of Wallingford. In 1972 the Brook was piped from a point 600 m. east of its confluence with Bradfords Brook. Now they are little more than agricultural drainage channels. Adjacent land use is mainly intensive agriculture. The watercourse has poor morphology, water quality and ecology with plenty of scope for habitat enhancement and the creation of buffer zones adjacent to the watercourse.
The courses of the two streams, as in part of the Mill Brook upstream from South Moreton, were in alluvium laid down in the Bronze Age and Roman times. An important feature of this alluvial land is its flatness. The land at road level by the Mill Brook in South Moreton is at 48.3 m whilst the level at Hithercroft is at 47.0 m implying a difference of 1.3m in levels over a distance of 4 km. As discussed above the two streams over time have been extensively modified for flood alleviation or navigation.
The system is classified by the Environment Agency as a river and designated Hydromorphologically as not being an artificial or highly modified water body.
The Environment Agency has designated most of the catchment as a Surface Water Nitrate Vulnnerable Zone (NVZ). They have one monitoring point along the length of the system the results of which show that the greatest load from nitrogen compounds is of agricultural origin.
Environment Agency Classification for the Mill Brook and Bradford’s Brook system
|2009 Cycle 1||2016 Cycle 2||Objectives|
|Water body status overall||Good||Moderate||Good by 2027|
|Ecological Status||Good||Moderate||Good by 2027|
|Chemical Status||Does not require assessment||Moderate||Good by 2015*|
*As reported in Environment Agency's WFD Classification Status Cycle 2 v3 data set published 18th May 2017.
As can be seen from the table above, in 2016 the Environment Agency classified the Ecological Status of the system as Poor overall primarily due to a Poor Biological Quality Component mostly related to the macrophytes and phytobenthos elements being classed as Moderate. For the Physicochemical quality component Phosphate was the one component to be classed as only Moderate that stopped this achieving Good status. However, the overall Water body Status for the Mill Brook and Bradfords Brook system is predicted to be 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.