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Accessible design methods for geosynthetics used for erosion control on channel and river banks

The design of geosynthetics used in erosion control on river and channels has evolved over the last 50 years from its early use in land reclamation and protection in fascine replacing willow/ brushwood rafts with woven synthetics. Much empirical experience has been gained throughout Europe. Machine made synthetic sheet like materials which have much tighter quality control can be studied in detail in the laboratory in a consistent and systematic way. To add to practical experience testing and design development has occurred and many often complex filter rules have been developed and publicised. However, it is often the case that designers do not have the luxury of sophisticated soil investigation reports for the intermittent embankment erosion schemes they have to design. This paper seeks to point the designer to theestablished design rules but also highlights a new pragmatism developed more recently helping designers focus on more practical elements of installation through service life and maintenance and a greater emphasis on working with nature with a much simpler approach. Designers are given tables and simpler guidelines to cover the majority of designs which have been developed from sound research and experience. A brief preview is given of this new approach which is the basis for latest directive, soon to be published, by the Dutch authorities who have consulted widely highlighting a more realistic and accessible design approach. Reference is also made to the concept of managed overtopping of embankments and the need for reinforced engineered vegetation.