Keeping our rivers flowing, Hertfordshire
On 10 July 2014, six volunteers from four different directorates participated in a “Himalayan Balsam Pulling Day” that was hosted by the living rivers officer from Herts and Middlesex Wildlife Trust.
The event to protect chalk stream biodiversity took place along the River Beane, a precious chalk steam in our supply area. An interesting fact is that there are only around 210 chalk streams in the world. That makes them rarer than Giant Pandas and a large number of them are found in Southeast England.
All in all the day was a great success and our staff were able to work alongside: local charity members, HMWT, local interest group the River Beane Restoration Association and community volunteers. This collaborative approach from all involved enables everyone to make a contribution towards river restoration, through invasive non-native species control. All participants enjoyed being outdoors and thought it was a good physical activity. Furthermore everyone involved also had a chance to learn from experts who knew about the history of the river as well as about invasive species identification and control.
Otter Holts, Hertfordshire
When Herts and Middlesex Wildlife Trust (HMWT) contacted us for a donation of drainage pipe to build an artificial Otter holt, we were more than happy to help out. Within a couple of months a team of Trust staff and volunteers had constructed the new home in the Lee Valley using some surplus polyethylene pipe and some recycling boxes donated by Stevenage Borough Council.
The HMWT Conservation Manager said: “Otters are still very rare animals in Hertfordshire, there are only a handful left, so it’s really important we take action to help the Otters that are left, enabling them to thrive. Providing secure places for them to live and breed is important in their survival. Otters only live for three to four years in the wild, so unless they’re successful breeding, they could become extinct.”
There are many different styles of Otter holt, but the pipe and chamber holt that has been built using our pipe is the best kind – it is long lasting and extremely secure.
Along with the holt, the Trust has created fish refuges in lakes by felling some trees, so the crowns of the trees rest below the water. “The submerged tangle of branches and twigs provide a safe place for fish to survive during the winter months and breed,” continued the HMWT conservation manager. “The Otters then benefit from the abundance of fish.”
The holt was constructed in a known favourite quiet area for Otters, a space that’s unlikely to be disturbed by people or dogs. Over the next year, the Herts and Middlesex Wildlife Trust will monitor the holt for evidence of usage.
Water Vole surveys
On 9 April 2015, a number of scientists from the Water Resources team attended a Water Vole survey training day. This was hosted by Herts and Middlesex Wildlife Trust at Denham Country Park, Buckinghamshire.
The training enabled team members to gain knowledge and experience of Water Vole surveying so we can deliver in-house surveys as part of our biodiversity programme. This has led to one of our Environmental Projects Officers carrying out an investigation into the population of water voles on the River Mimram.
There is currently an isolated population of approximately four Water Voles that are permanent residents on a stretch of the River Mimram in the Lee Community. They are often seen by local home owners as they have unusually built a series of burrows utilising gaps in the bridges of their back gardens. Evidence suggests that there are also isolated Water Vole populations on other parts of the River Mimram. It is hoped that habitat improvements carried out in the area will increase Water Vole populations on other parts of the river.
Lea Catchment Partnerships
The River Lea and its tributaries - the Mimram, Beane, Ash, Rib, Quin and Stort - drain over 1,000 km2 of Southeast England. These rivers include rare and precious chalk streams, canals and navigations, and urban watercourses. There are several catchment partnerships made up of people and organisations such as landowners, local community groups and charities, councils and government agencies which are working to improve these rivers for people and for wildlife. The partnerships were formed between 2012 and 2014.
Each partnership is ‘hosted’ by one organisation, whose role is to organise and co-ordinate the many different members of the partnerships, as well as develop a catchment plan and drive the objectives forward. They also act as the initial contact point for any enquiries about each catchment and arrange the regular catchment partnership meetings and workshops.
Over the next five years we will undertake environmental improvements on these rivers. We currently sit on the steering groups for the various partnerships and work closely with the catchment hosts and the communities they serve. The main aims of the Lea Catchment Partnership are to improve water quality, manage flow, control non-native invasive species and improve wildlife corridors. The partnerships also aspire to involve people in their local water bodies and achieve improvements by working together.
For more information about the various Lea Catchment Partnerships or to get involved, please visit www.riverleacatchment.org.uk
River Beane habitat enhancement
The River Beane is a chalk stream tributary of the River Lea. For the section of the River Beane that flows near Watton-at-Stone, it is very over-shaded which results in a lack of marginal vegetation, due to the reduced amount of light reaching the river channel. An old weir along the river had prevented fish from moving up and down the river. This site is also in a catchment where we will be reducing abstraction to help improve flows (see sustainability reductions section).
We are undertaking environmental improvements in areas under stress in this river until 2020. The habitat enhancement work includes the thinning of trees that are over-shading the river, to allow more light and help aquatic plants to grow. A number of large fallen trees which are completely blocking the river will be removed and large woody material from the tree thinning will be fixed into the banks to create refuge areas for small fry, creating additional habitats for aquatic insects.
The residents in the area intend to carry out some marginal planting, using native species once the trees have been thinned. Removal of the top of the small weir has allowed fish to move up through this reach and make use of the new habitat created as a result of the enhancement work.
Over-shaded river Small weir