River restoration was recently described to me as being more of an art than a science. Well, it’s hard to avoid the conclusion that it is a somewhat subjective practice. That isn’t to say we can’t lay down some guidelines. What should we always try and do when we’re doing river restoration?
DO engage stakeholders: a large element of river restoration work involves educating people about the way in which our watercourses would naturally function. Additionally, by including different people you can better appreciate the multitude of concerns likely to arise from your planned works. An increasing number of projects are involving volunteers, which is both instructive and cost-effective.
DO get expert opinions: Try and get as much independent, expert advice as possible. People’s notions of what constitutes good river restoration may be distorted through experience, training or personal bias. It’s only in the last decade or so that applied fluvial geomorphology has really come to the fore, and society’s understanding and requirements of rivers is constantly changing.
DO set clear, achievable aims and objectives: Think about the specific forms and processes you wish to create. Are you hoping to improve spawning habitat for salmonids, and hence require gravel-bed substrate and fast flows, or do you want to attract wading birds and hence require the creation of an offline backwater that’s periodically inundated? Although a generic aim of ‘increasing biodiversity’ or ‘enhancing habitat heterogeneity’ is both commendable and desirable, it is easiest achieved using specific objectives.
DO be holistic and try to work at the catchment-scale: This can be quite hard. In reality only small pots of money may be available and you simply haven’t got the resources to consider everything. Nonetheless, consult the River Basin Management Plan for that district, look upstream and downstream, and get a good grasp of how your planned works fit into the grand scheme of things.
DO monitor post-restoration: The best way to assess whether your project has been a success is to go back to the site and quantify any changes in your target elements (e.g. if your objective was to create habitat for sea trout, are there now more sea trout? Are they older or younger? In good conditions or otherwise?). Ideally such monitoring should encompass as many biotic and abiotic indicators as possible (there may be improvement in your target elements but deterioration in others) and recur for several years after restoration. The cost of monitoring should be budgeted for from the outset.
DO share your successes and failures: The River Restoration Centre in the UK and the EU RESTORE group contain great repositories of river restoration works that have taken place. It may be appropriate to write a scientific paper if you’ve employed a particularly original technique, or you could set-up a website or write a blog about your restoration work. Whatever ever you do, whether your restoration was good or bad, share it so that we might improve our knowledge and understanding for the future.
I’ll be blogging another post shortly, looking at the DONT’s of river restoration. In the meantime, what do you think is essential in making river restoration work?