Advances in Water Treatment and Enviromental Management

Chapter 21GREEN ENGINEERING: THE CASEOF LAND DRAINAGEJ Pursglove (Mott MacDonald Ltd, Cambridge, UK)SUMMARYEngineers working on roads, rivers, dams, tunnels, bridges, landfill sites, quarriesand buildings all have a profound effect on the environment. Some industriallandscapes, largely created by engineers in the canal age, for example, are nowvalued as exciting places to visit and enjoy. In our time, however, engineers havebeen rather more associated with the destruction of the environment. Roads havebeen and continue to be the subject of fierce environmental controversy. Rivershave been straightened out and their banks have been stripped of trees andconcreted, as part of land drainage schemes. Waste management engineers haveoften assumed that landscapes which do not make a profit for their owners, suchas woodlands and wetlands area automatically ‘derelict’ and therefore good placesfor dumping rubbish in.These problems often arise because of the narrow brief which engineers are given.With a wide brief which includes the environment, they can even improve theenvironment. Land drainage schemes present an opportunity to plant trees andcreate ponds which were previously the victims of drainage. Roads, once care istaken to chose the best possible route for them, can create the opportunity to reestablishhedgerows and woodlands in the adjacent countryside through whichthey pass. The budget for this will be a tiny fraction of the engineering cost of theroad building. Landfill sites may also create sufficient profit for a proportion to beploughed back for the creation of adjacent habitat.This ‘green brief for engineers is worthwhile because it contributes to the quality oflife—something we all need as well as water for the reservoirs or an effective transportsystem resulting from road building. However, there are also plenty of hard-headedreasons for green engineering. Minimising on topsoil on road embankments savesmoney and creates ideal conditions for wild flowers. Trees planted on river banksas part of land drainage schemes both shade out aquatic weeds which wouldotherwise block the channel and help to reinforce eroding banks. Structuralengineers involved in the construction of industrial estates are quick to grasp thata well landscaped ‘science park’ can command higher rates than a run-downcollection of tin sheds. In addition there is always the real benefit of good publicrelations for a genuinely ‘green’ engineering scheme.© 1991 Elsevier Science Publishers Ltd, EnglandWater Treatment—Proceedings of the 1 st International Conference, pp. 219–222219