Applying Optimisation and Uncertainty Analysis to Help Develop an Integrated Water Resources Plan for South East England

The need to promote opportunities for integration between commercially independent water supply providers is becoming important as pressure on water resources increases in many parts of the world. Water stress in south eastern England is projected to increase over the next 25 years, influenced by factors such as: population growth; demographic change; changes in water use; water requirements for environmental protection; and, the potential effects of climate variability and change. Actions to avoid unacceptable deficits in the supply–demand balance are being planned, involving measures to reduce the demand for water and schemes to increase the sharing of water resources within the region. This paper outlines the application of a modelling framework incorporating optimisation modelling and stochastic simulation to help identify options to improve the integration of water resources systems across the region. The regional modelling framework has helped to identify integrated sets of schemes that can provide a cost-effective regional solution for securing the supply–demand balance at an acceptable level of security of supply. These integrated sets of schemes include shared water storage and transfer options that are broader in scope than those considered by individual water companies in drawing up their own water resources plans. Outcomes to-date have included: (a) the identification of cost-effective opportunities for shared resource development and new infrastructure to transfer water from areas of surplus to areas of deficit; (b) interest from the six commercially independent water companies across the region in looking beyond their own water resource zones to develop a better integrated and more sustainable water supply and distribution network across South East England; and (c) valuable insight which is being applied in further regional modelling work to inform the development of the next round of water resources plans due to be submitted by water companies in 2014.