Last Saturday, the DRY Project led a walk along the River Frome in Yate. Despite the torrential downpour that finished minutes before the walk was due to start, we had a good turnout, and the weather brightened throughout the afternoon. We began the walk at South Gloucestershire Council Offices and were joined there by Chris Knight, who told us about the various sustainability features installed in the building, such as the rainwater harvesting system incorporating run off from the roof and the car park, and the challenges that such measures can bring.
From the Council Offices we headed down Stover Road to join the Frome Valley Walkway. Before we joined the path, Nevil (from the Project team) passed out a map with our route marked out. The modern map overlaid the 1st edition Ordinance Survey map from 1882 and it was interesting to note how much the direction and shape of the river had changed during the development of Yate. As we started out along the route, we began to notice Himalayan Balsam by the side of the river. Neil Green (Bristol Zoo Invasive Species) told us about the invasive species along the River Frome and the projects they are running on Giant Hogweed and the Asian Hornet. Our youngest walker enjoyed jumping in the mud along this part of the river path. Further down the path, we met up with Tony Smith (Bristol Naturalists) who, prior to our arrival, had been wading in the water with his net, sampling for invertebrates. He had plenty of fresh water shrimps in his trays for everybody to get a closer look at and several other samples of river flies, including caddis fly (cased and free living) and mayfly larvae. Freshwater invertebrates are used as a biotic indicator of river quality. The long term quality of water can be assessed by looking at which species are found in the river; the cleanest rivers have the greatest diversity and most sensitive species. From the sample Tony took at this point in the Frome, the water quality is not amazing, which is unsurprising given that it runs through the industrial estate.
To our surprise, as we ducked under another bridge, we ran into a colleague from UWE who was researching ecosystems services on the
River Frome. We filled out his survey on recreational benefits of the river, before carrying on. We then crossed the railway track to leave the section of the river that runs through the industrial estates and move on to a more residential section. Harriet then talked us through the work Bristol and Avon Rivers Trust do on the Frome and demonstrated how to test for phosphate and nitrate in the river. We each had a little plastic tube which had to be filled half full with river water. We then watched to see what shade of pink it turned. The water only turned a very pale pink colour meaning that the river has relatively low nitrate levels. If you are interested in getting involved with this river monitoring work, for which free training is provided, find out more at: http://www.bristolavonriverstrust.org/who-we-are/rivers_trust_supporters/.
Towards the end of our walk, Paula Spiers (Avon Frome Partnership) talked to us about the changing approaches to managing a river in an urban setting, so that instead of getting the water down the river as quickly as possible (which may lead to flooding downstream), it is now held and slowed down upstream. Lindsey (from the Project team) then introduced some of the research the DRY project has been carrying out on the hydrology and land use of the catchment, showing how observed rainfall data spanning back to the 1960s indicated several episodes of drought, of which 1976 was the most extreme. She left us to ponder over whether it is necessary to be prepared for an event equal to or worse than 1976 or repeated events like 1976.
Thanks to everyone who joined us on the walk.