Stormwater Shepherds UK worked with the Catchment Based Approach team and the River Douglas Catchment Partnership to convene an event in Wigan in Lancashire in October. The event was a combined workshop and conference to discuss the extent of the highway runoff pollution affecting the whole of the River Douglas catchment. 50 people attended the event from over 30 different organisations.
We discussed the magnitude of the problem, with over 40 motorway outfalls entering the river and its tributaries, and perhaps another 40 outfalls from the other roads around Wigan, Leyland, Skelmersdale and the surrounding areas.
As the day unfolded, it was clear that local people, living and working around the river, were the best placed to identify opportunities to treat highway runoff and to reduce the extent of the pollution. The Rivers Trust, the local water company, ‘friends’ group and Groundwork know where the river is most vulnerable, where there are opportunities to deliver solutions and which landowners might be able to help. This local knowledge is missing at National Highways, so by working in partnership with all the local ‘players’ in the river environment, National Highways may be able to spend their money more wisely, and to deliver more treatment schemes are more outfalls more quickly.
Since the event, we have calculated that the 40 outfalls into the River catchment drain 157 hectares of motorway surface into the River. Assuming a sediment yield off that motorway surface of 3 tonnes/hectare/year, that’s almost 500 tonnes of contaminated sediment entering the River catchment from the motorway every year. The sediment is contaminated with toxic metals, hydrocarbons and microplastic tyre-wear particles, all of which are harmful to river life.
Stormwater Shepherds UK will continue to work with the partners across the catchment to try to speed up the delivery of solutions for this pollution. If you live in Lancashire and you’d like to help, drop us an e-mail at jo.bradley@stormwatershepherds.org
