The River Slea is an 18 mile long tributary of the River Witham in Lincolnshire. It is a spring fed, perennial river based on the Lincolnshire limestone aquifer. Historically the River Slea flowed all year round, but in the early 60s the flow of the river began to slow and ceased in 1962. After a public campaign, a pump was installed by the Environment Agency, which delivers groundwater to the river at times of no flow. However, the river lacked many natural features to aid resilience during low flow. Prior to the project, sections of the river would run dry and excessive weed growth would clog up the channel.
Using an excavator in the first section, a small channel was created to retain water when the river levels fall in the summer. The low flow channel quickly fills up once the underground aquifer is full and the springs are feeding the River Slea. This section is now flourishing. Surveys completed before the work showed no evidence of water voles, but there are now burrows, feeding stations and even the presence of this chap happily feeding away – a great sucess!
Blood Sweat and Volunteers….
An excavator was also used in the second section, where the riverbed material was dug from the channel to create pools and dumped to create berms. This was a particularly tricky area between houses and a public footpath. The river bed was impermeable in some areas. Brushwood bundles were installed to construct berms which created pinch points, narrowing the channel to speed up the flow and maintain the pools created. 300 plug plants were planted including yellow iris, pond-sedge and soft rush. This part of the project was made possible with the help of volunteers.
The project was commended in the Lincolnshire Environment Awards 2018.