Urban Drainage & Green Infrastructure

This lecture addresses the need to reduce the impact of city development of flooding on residents and in other places, and the worsening of the water quality in streams, rivers and lakes caused by the expansion of cities. Jefferies believes the most appropriate current solutions involve Sustainable Urban Drainage Systems (SUDS) but SUDS can only be implemented with good policies, supportive stakeholder groups and partnership working so that these new ideas, which cut across existing methods and practices, can be accepted. Sustainable Urban Drainage Systems require several changes in thinking and practice in city planning and there are many barriers to progress including the perceived costs added to development, the increased maintenance activities required, the attractiveness of big infrastructure projects to politicians whereas drainage projects are very often just ‘normal work’. The inertia of planning systems also tends to discourage the good new ideas involved. However, the perceived additional costs need to be set against the costs of losing habitats and the fish, food and other ecosystem services which follow, and the damage to properties and danger to people caused by flooding which frequently results from development. The barriers to more sustainable drainage are high but a whole portfolio of potential ‘Green’ infrastructure solutions are available to be applied in any city in the world. There are no particular problems for high cost, high value developments since the additional costs of drainage are small and green space is normally an integral element.