Another crackingly busy month kicked off with surveying a ditch called Butterfly Cottage Dyke for the Internal Drainage Board.
A blisteringly hot day saw me putting the previous month’s Natural England training to
good use by identifying the many species of rushes and sedges that grown along this botanically rich channel. The waterway supports rare plants such as Tubular Water Dropwort and Hairlike Pondweed. My work involves advising the Drainage Board on how to manage the channel to benefit these and other species and look at ways of improving its value for wildlife.
Unfortunately many of our waterways suffer from Nitrate and Phosphate pollution often caused by historically overloading the land with fertilisers. Agrochemicals are big business and firms have lobbied farmers for fifty years to buy them in order to achieve higher yields and cut down on ‘pest’ species. Often land is overburdened with chemicals and much ends up seeping through the soil and fertilising rivers and drainage ditches which then sprout lush growths of plants such as watercress which can impede flow and cause flooding.
Over 8 years of surveying for the board I have also seen a change in land use with formerly grazed fields becoming fallow or cut for silage and more maize being grown. These changes are not good news for wildlife. Ditches alongside grazing marsh are often botanically rich as the action of animals grazing the channel opens up niches for wildlife while maize crops are often bad news next to rivers as after harvesting, the field is left with bare earth which can be washed into rivers in winter storms creating siltation issues which can lead to flooding.
Despite years of environmental subsidy schemes for farmers it seems that more needs to be done to tailor advise to farmers and put a healthy and wildlife rich countryside at the centre of farming policy not just tinker at the edges of farms and ignore the real issues.
However, the Internal Drainage Board are working to improve watercourses and this month I returned to Port Rill with volunteers from the Kentish Stour Countryside Partnership to finish installing woody debris in the channel. Fallen dead branches were pinned into place by the volunteers and should help create shallow marginal shelves along the edges of the channel while creating faster flow in the centre, cleaning gravels and creating oxygen rich water. This month we saw fish in this channel for the first time, a real testament to the volunteer’s efforts.
A month of river work finished with a survey of Pig Brook, another IDB managed channel which holds one of the last populations of White Clawed Crayfish. This native species is suffering through the spread of Crayfish plague spread from imported signal crayfish as well as pollution and silt covered gravels.
Earlier in the month I had given a talk to the drainage board’s contractors Rhino Plant on the importance of biosecurity and the need to check clean and dry equipment and spray with a specialised Iodine based spray when working on crayfish channels.
Pig Brook is an attractive channel set in parkland but more could be done to improve the stream for crayfish and connect it with the surrounding floodplain. Next month I hope to work on plans to enhance the river and allow the crayfish to thrive.