UNCERTAINTY IN THE ENGINEERING OF WILDLIFE HABITATS

Environmental systems are inherently unstable over time-scales appropr iate to planning and management. As knowledge relating to rivers and t heir floodplains increases, uncertainty is increased rather than decre ased. As the limits of what is known become defined, a better apprecia tion of what is not known is gained. The creation of wildlife habitats in rivers and on floodplains has been referred to as an art rather th an a science. This paper highlights some of the many questions which r emain unanswered as environmental managers strive for more sustainable and cost-effective projects.