About the Ivel catchment
The River Ivel catchment is bounded by the Chiltern Hills to the south and Greensand Ridge to the North. The Rivers Ivel and Flit, and some tributaries, rise from springs in the Chiltern chalk. Several smaller watercourses (Running Waters, Chicksands Brook and Millbridge Common Brooks) rise from the Woburn Sands aquifer. The River Ivel headwaters are dominated by Hitchin, Letchworth and Baldock. Further along the rivers are Ampthill, Biggleswade and Sandy. Elsewhere the catchment is mainly rural with agriculture and horticulture. The catchment is noted for its angling interest, water vole and otter populations and important wetland habitats.
The Environment Agency has been surveying and monitoring water quality in the Ivel catchment against WFD criteria since 2009. Details of the findings can be found from page 27 in the Upper & Bedford Ouse Management Catchment – Catchment Summary.
In both 2009 and 2013, approx. 33% of water bodies in the Ivel were classified as being of Good status. However, in 2013, there were fewer Moderate and more Poor water bodies. There is clearly much work for the Upper & Bedford Ouse Catchment Partnership to do – both as a partnership and through its constituent members – particularly those with statutory responsibilities, such as the Environment Agency and Anglian Water.
Investigations by the Environment Agency since 2009 indicate that the top 3 reasons for more water bodies in the Ivel operational catchment not achieving ‘Good’ status are:
- pollution from waste water – particularly from the water industry, but also from industry, manufacturing and other business;
- physical modifications to watercourses (including in-channel structures and channel straightening) – associated with a range of activities including industry, manufacturing and other businesses, transport and agriculture;
- negative effects of non-native species, in particular Himalayan balsam, Japanese knotweed, giant hogweed, floating pennywort and signal crayfish.
The Upper & Bedford Ouse Catchment Partnership together with local groups, land owners and interested parties are working to identify projects and activities which can address these issues, to maximise the number of Good water bodies within the Ivel operational catchment.
Please navigate around the Ivel operational catchment map to see current, planned and completed projects. More projects will be added in the coming months and years.
Projects/River Warden Updates – Ivel
The current volunteering activities are building on the work of BRCC staff and volunteers in the Ivel catchment over the last 25 years, having spread out wardening from initially just the Millbridge/ Potton Brook we are now covering parts of a number of the tributaries of the Ivel and some of the Ivel itself. Some baselines are still to be completed but please do continue to undertake your monitoring visits and fill in the online forms. We are looking to cover as much of the catchment as possible.
Several areas have been noted by wardens as suffering from worsening erosion, mainly due to cattle and dogs gaining access to the river and in some places this is leading to damage to footpaths. This has led to some projects being developed with Central Bedfordshire Council to stabilise and restore the banks and once these have been finalised and consented we will be putting out an appeal for help to actually undertake the practical works installing brash bundles into the river.
In addition to monitoring walks some volunteers have undertaken a wide range of river improvement works, particularly at Gamlingay and Biggleswade and these continue to be monitored by wardens, fixed point photography and by invertebrate sampling. This is currently being targeted at sections where we have undertaken works in the past but we would like to expand it to the wider catchment. If either fixed point photography or invertebrate sampling is something that you would like to get involved in please do get in touch.
The Gamlingay works were undertaken on a nearly straight section of steep banked water way (The Millbridge Brook). The channel was suffering from siltation, being choked by weeds and there were some areas where over steep banks were collapsing. With permission from the Bedford Group of Internal Drainage Group volunteers cleared a central channel through dense vegetation, installed brash bundles to protect the banks and narrow the channel in over-wide sections of channel and installed log to act as flow deflectors to give more flow diversity. A pile of brash was installed to divert flow into a back channel to add a more naturally sinuous form to the channel. These features seem to have been a great success with a clear gravelly bed now being evident in places and there is a greater diversity in flow features such as fast moving water and small , still pools. Continued monitoring will hopefully show that these works have improved the invertebrate diversity here too.
At Biggleswade a number of works were undertaken in partnership with the Environment Agency. This included some heavy machinery being brought in to re-profile rapidly eroding banks to draw them away from the river to reduce the likelihood of further material entering the channel, contractors also installed an engineered cattle drink and temporarily fenced of some sections of bank to exclude cattle. Volunteers then came in and installed brash bundles in a number of eroding sections, and temporarily fenced off some smaller areas. Bare banks were re-seeded and some bank side trees were planted. A length of brash bundling was installed along the old bank line where a large pool had eroded, where the channel had become over wide and where crayfish had eroded the bank. In addition a felled tree was staked in place to provide an in channel flow deflector and some rubble was moved to be added to an existing flow deflector. Monitoring continues but erosion has been reduced or eliminated in many places worked on and there is now a build-up of material re-creating the old bank lines behind the brash bundles. Clear gravel bars have formed where flow deflection has occurred and crayfish have been displaced where bundles were installed in front of their holes. Wardens continue to monitor these sections have reported that several new areas are now suffering from increased erosion. We are discussing a longer term solution with the land managers.
–Richard Lawrence (Bedfordshire Rural Communities Charity)
Projects/River Warden Updates – Flit
It has been another busy year keeping on top of the invasive Himalayan Balsam on the River Flit. Work has continued tackling the Balsam from its most upstream point, reducing the impact of seed spread downstream.
The Himalayan Balsam removal project covers 12.7km of the river Flit and tributaries plus 40.6ha of adjacent habitat comprising Flitwick Moor Sites of Special Scientific Interest (SSSI), three County Wildlife Sites (CWS), three non-designated areas of woodland, field edges and ditches. The Balsam project is entering a new phase where upstream areas of Balsam will be eradicated as far as practically possible to ensure the continued trend of reducing Balsam plant density downstream on Flitwick Moor.
The River Flit also has 4 river wardens currently surveying, covering the areas in and immediately around Flitwick Moor. These wardens keep a sharp eye on the Balsam in this area to ensure it is kept on top of, alongside their normal river warden surveying. With Flitwick Moor being a sensitive site it is also important the river wardens keep an eye on the areas of the Moor alongside the Flit that flood so we can continue to monitor the impacts of the enriched (and slightly alkaline) water from the River Flit on the more acidic Moor.
We want to know if you have seen this plant in your area. If you have seen this beautiful yet aggressive invader let us know!
Be sure to provide a location of any Himalayan Balsam you find so we can map it accurately.
– Lewis Dickinson (Wildlife Trust Beds, Cambs & Northants)