SUSTAINABLE MANAGEMENT OF GROUNDWATER SUPPLIES IN URBAN AND PERI-URBAN AREAS

Management of groundwater in urban areas is beset with difficulty. First and foremost is the hydrogeological complexity of the urban subsurface, a region which is often highly disturbed by construction activities and host to a multitude of urban-sourced contaminants, many a legacy of unsound practices of past generations. The problem is compounded by growing demand for water, particularly in suburban areas, and the burden of managing increasing volumes of wastewater without causing further degradation of groundwater quality. In such an environment, it is no surprise that strategies for urban groundwater management are rarely planned proactively, well supported by science and appropriate field data, and instead tend to be developed “piece-meal” with decisions made hurriedly in response to pressing demand and/or water quality issues. This needs to change. Recognising that many of the world’s cities are facing explosive growth, it is time to make better use of the sophisticated urban groundwater models developed in recent years to develop blueprints for the sustainable development of available urban water resources. Proactive management measures can range from managed aquifer recharge (better known as artificial recharge) which already enjoys considerable success in many water-stressed regions of the world, to more innovative “fit-for-use” schemes that allow non-potable urban groundwater sources and/or treated wastewater to be appropriately utilised. For example, in some cities, the demand for potable water could be met more readily from peri-urban wellfields if agricultural demand for irrigation water in those peri-urban areas could be met with treated urban wastewater. In many respects, the science and engineering needed to underpin the sustainable management of groundwater supplies are already in place. For many cities, the real obstacle to effective urban groundwater management lies in the systems of water governance that fail to consider the urban water cycle holistically. Urgently required are institutional and regulatory frameworks that embrace the entire urban water cycle (including groundwater, surface water and wastewater) and are able to fully integrate urban water-supply and mains sewerage provision into the urban planning process.