Restoration of Streams in the Agricultural Landscape

Abstract

The advent of easily-accessible tile-drainage and the intensification of agricultural practices have brought widespread decoupling of streams and their riparian floodplains in agricultural streams over the last 150 years. Channelised and deeply incised in the landscape, these streams are more than often reduced to simple drainage ditches – when not simply running in underground pipes. This paper describes a modular approach to bring back the key functions and ecosystem services provided by lowland streams that still must perform their drainage purposes in an agricultural landscape. Five principal restoration measures, also referred to as “building-blocks”, are discussed: re-creation of buffer-strips, alteration of tile drainage, in-channel interventions, creation of riparian wetlands/ponds, and finally daylightening. The complete restoration of a stream ecosystem may not be the most acceptable option to farming communities. In most cases, however, the application of even the most basic measure (i.e. the buffer-strip) can significantly support the return of key ecosystem services provided by a stream; such as flow regulation, water purification and support to biodiversity. Cumulative implementation of the other measures at strategic points of the drainage basin will further ensure that a functional stream/river valley is reinstated.