The River Crane Is a Small Tributary of the River Thames in West London
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The Citizen Crane Project The River Crane is a small tributary of the River Thames in west London, with a catchment of around 127 sq km and a main channel length of around 35km, extending over five boroughs (Harrow, Hillingdon, Ealing, Hounslow and Richmond). The Crane Valley Partnership (CVP) was WATER QUALITY DATA set up in 2005 and brings together representatives of each borough along with the Environment Agency (EA), Thames Water (TW) and a range of third sector groups, to help oversee the management of the catchment. The Citizen Crane Project was set up in early 2014 to investigate the water quality in the River Crane, using teams of citizen scientists, and Headstone Manor following major pollution incidents in 2011 and Figure 1. Mean ammonia and soluble reactive phosphorus loadings along the river (kg/day) for 2013. Spider Park 2015 The project supports a network of around 50 Headstone Manor The upper reaches of the river are in a poor condition volunteers, collecting samples and data at due to heavy inputs of P and NH3. The middle monthly intervals from 11 sampling sites spaced reaches show better water quality, but loadings along the river system. Over 2000 volunteer continue to increase, and poor geomorphological hours have been invested over the first two diversity means poor ecological diversity. The years of the project. ecosystem improves markedly towards the lower Roxbourne Park ) Ickenham Marshes Arm) reaches, and overall loadings also start to fall as the The project includes: m system is able to start coping with the inputs. Note: Ar stern Newton Park West • Monthly RMI (Riverfly Monitoring Intitiative) – rn (Ea the step increase in P at Crane Park is due to a high Spider este ecological assessment West k inflow, via The Duke of Northumberland’s River, from Park (W o Newton Ruislip ok ro the River Colne. • Monthly P and NH3 sampling/analysis – ro B Park West g B g concentration of key organics e adin in Y South d Northolt • Monthly flow monitoring – translates P and Ickenham a Ruislip e Park NH3 concentration into loadings Marshes RAF Y RMI DATA ch) NORTHOLT ran • Monthly checks of key polluted outfalls n B Gutteridge gto • Review of real time water quality data from din Wood ad other sources (P al Ten Acre Wood n • “Outfall Safari” assessed the impact of 227 a Y C outfalls along the catchment in 2016 e a n o • Developing a conceptual model of the river d i i n quality and ecology n U g B • Using this model to influence and support ro d o n investments and investigations by the k a Yeading r Environment Agency and Thames Water Yeading Brook Meadows G • Engaging the public and third parties, including Brook Minet Country Park local universities Meadows Figure 2. Mean annual RMI data for 2014 and 2015 • Promoting the approach in other catchment Minet Country Park The Riverfly Monitoring Initiative (RMI) was developed areas by the Riverfly Partnership (www.riverflies.org) and Southall al launched nationally in 2007. It is now deployed by an C around 2000 volunteers on 1500 sites across the UK. Hayes & on ni The aims of the RMI are to assess the ecological OUTFALL SAFARI Harlington U e d condition of the river and detect pollution problems. n n ra Greater invertebrate diversity, including the only Citizen Crane data indicate that P and NH3, derived a G in significant part from surface water outfalls, are r records of true mayfly (Ephemeridae), has been C Cranford found at concentrations damaging to the river ecology. r recorded with distance downstream. Gammaridae Misconnected domestic pipework, cross connected Park e is the only RMI group to be found at all sites and v sewers and combined sewer overflows are each i stonefly (Plecoptera) are found at none. R Donkey Wood sources of the pollution load. In 2015 Thames Water started a clean-up of misconnections at 64 outfalls as part of a five year regional Surface Water Outfall Cranford Park Isleworth r Programme (SWOP). f d’s Rive o n REAL TIME MONITORING a l Following a pilot study in 2015, The Citizen Crane e HEATHROW r k project ran a first “Outfall Safari” in 2016 to: Donkey Wood e U u ppe b • Map the dry weather condition of surface water r D (River Crane & DNR) D e u e of Nor k m t n outfalls across the catchment hum ’s River r u b and e erl h a t r • Create a common catchment method for assessing w r Hounslow Heath o o C the impact of polluted outfalls L N r ve • Develop a low cost recording method (incorporating Feltham Whitton Ri an App) L o Crane Park Twickenham n es g Island m The volunteers fo a r h d T photographed, R iv Mill Road Weir r geolocated and e e r v i Figure 3. Plot shows diurnal variations in DO and an assessed over R overall fall in DO in response to reduced flow and 200 outfalls, increased T (data from the EA, May 2016). compared to 154 identified The team reviewed real time monitoring data from in a 2014 the Enviironment Agency and Heathrow Airport to Thames Water supplement Citizen Crane data. These revealed (a) survey. Of this major diurnal variations in dissolved oxygen in parts total 64 (28%) showed signs of pollution and more of the river – a likely direct outcome of its eutrophic condition – and (b) discrete peaks in NH3 levels than a dozen have already been investigated further Crane Park Island by the Environment Agency or Thames Water. (typically for a few hours every few weeks) in addition to chronic background inputs. Mill Road Weir Map Data Source Environment Agency, contains Ordnance Survey Data © Crown Copyright and Database Rights (2017) SURFACE WATER OUTFALL PROGRAMME (SWOP) Thames Water data for a single (and typical) SWOP outfall indicate the nature and scale of Citizen Crane data are now being used by the Environment Agency and Thames Water the misconnection issue. to prioritise outfall investigations and rectifications across the catchment. Appliance Misconnections An enormous added value comes from the improved community understanding of the Resolved river’s ecology and consequent increased sense of stewardship. washing machine 67 dish washer 30 The following strategies and objectives have emerged from the project: kitchen sink 50 bath 12 • Prioritise the upper catchment for chronic pollution reduction hand basin 38 • Improve the morphological character of the middle catchment shower 16 toilet 8 • Target key outfalls in the SWOP • Understand and eliminate the sources of ammonia spikes • Develop a better understanding of the impact of diurnal DO variations • Promote schemes to improve the ecosystem Friends of the River Crane Environment • Further investigate the P loadings from the River Colne The project is continuing for three further years to 2020 with funding from Thames Water. Detailed findings, along with the raw data, are available at www.cranevalley.org.uk Contact the project team on [email protected] .