London Zoo hosted the annual Hogsmill Forum, where professionals and volunteers including members of the Kingston University Biodiversity Action Group discussed issues faced by the Hogsmill River – a tributary of the Thames River which flows along the boundary of the Kingston School of Art. Discussions focused on how to implement solutions to improve the river. The South East Rivers Trust updated on issues relating to important catchment plans for the Hogsmill. The aim of the meeting was to improve communications between volunteers and the main agencies and groups working on the river and to support development of volunteer work in the river catchment.
A monthly Hogsmill Newsletter summarises the results of River Monitoring Initiative (RMI) sampling on the Hogsmill in February, together with other pollution monitoring and other river-related activities and events – click through to this link to access the PDF newsletter to find out more.
River Monitoring Initiative (RMI) is a national scheme for monitoring the health of rivers. Volunteers undertake regular surveys using a standard net sampling technique to count the number of certain “water quality sensitive” invertebrates. An overall “score” is then calculated. A sharp fall or a drop below a “trigger” level could indicate pollution. This can then be reported to the Environment Agency (EA) to enable further investigation. Misconnected wastewater pipes and cross-connected sewers are a major source of pollution in the Hogsmill. Under a Pollution Patrol scheme organised by the South East Rivers Trust (SERT), volunteers undertake regular assessments of the outfalls thought most susceptible to pollution, the results being reported to EA and Thames Water (TW) to help steer remedial work.
Thames 21’s “lab boat” – “HMS Kingfisher” – is being tested on the Hogsmill. This remote controlled boat has sensors that measure several indicators of water quality, such as dissolved oxygen, conductivity and temperature. Hopefully it will soon be able to measure nitrogen, phosphates and more. It also has software enabling the data to be geo-referenced and viewed in real time. The plan is to survey as much of the Hogsmill as possible over the next few months to create a map of water quality on the river and then to repeat this as often as possible over the rest of the year. The boat will also be available to measure water quality soon after any new pollution incidents or a sharp change in RMI score. Thames21 are looking for local volunteers to assist in surveys – contact firstname.lastname@example.org
Transforming the Hogsmill – Volunteers joined the Malden Manor Community Group for a clear-up by the Hogsmill in Old Malden. With support from SUSTRANS, the Kingston Environment Trust and the Ahmadiyya Association “large rubbish” was removed from the river bed; a riverside path was restored; and bulbs were planted. Scrub clearance beside the Tolworth Brook completed preparations for the “capital works” stage of the project to revitalise the Raeburn Open Space in Berrylands. Contractors are scheduled to start work soon taking out concrete banks, removing a weir and installing a new bridge.
Images: Peter Short
With Environment Agency funding and support from the local council, South East Rivers Trust is undertaking a feasibility study of ways to mitigate the impact on the upper Hogsmill chalk stream of the poor water quality in the Green Lanes Stream. It is currently investigating an option that would divert the Stream through a meandering channel across Chambermead meadow re-joining the main river about 200 metres downstream of the current confluence. Wetlands and ponds and scrapes would be constructed in the meadow that would reduce the impact of pollution and sediment and also lower flood risk by attenuating peak flows down the Stream. If you’d like to know more about the project contact: email@example.com