The installation of hard engineering solutions is common place, despite generally being an expensive option. Next time you are looking to engineer a solution for erosion or slope stability etc. why not consider a bioengineering solution? Not only could this save you money but it could boot your site biodiversity value and prove to be a more visually attractive solution.
Salix have some great case studies and are very helpfully in determining the suitability of the options available. http://www.salixrw.com/