In order to achieve the overall objective of representing and considering the entire water system of a city in one single model, a macromodelling simulator has been set up (working title "LiWatool"). It facilitates analysis of the complete urban water and wastewater system, including its input from the river basin and its interactions with the energy system. The system is represented by building blocks for each of its main elements (e.g. water purification plants, groundwater wells, water supply network, city districts, wastewater trunk sewers, wastewater treatment plants etc.). Additional modules, e.g. reservoir lakes, water reuse plants, desalination plants, will complete the set of modules required. City districts are characterised by, among others, population number, distribution to social levels, water consumption patterns, percentage of non-revenue water. Besides water quantity, also water quality (in water supply and in wastewater) and energy fluxes are considered. As any analysis of variants also includes a cost-evaluation, costs are also included in terms of capital and operational expenditure. For the cost evaluation, the cost categories as applied by the water company Sedapal have been implemented.
In the following picture, a (simple) application example of the macromodelling procedure in a part of Lima’s water and wastewater system (parts of Central and Southern city districts) is presented. For the description of the system, building blocks (such as groundwater wells, water purification plants, city districts etc.) have been used. The figure illustrates results of a simulation by illustrating the main fluxes of drinking water (abstraction from ground water, river water purification, “production” of wastewaters. Within this example, the results suggest that, based on the assumptions made, a shortage of surface waters is expected from the year 2013 onwards. More detailed analyses, obviously, would also include impacts on water pollution, treatment and energy aspects.
The water system simulator "LiWatool" models the entire water and wastewater system of Lima Metropolitana and assists in discussion and evaluation of various options, with regard to a number of criteria to be agreed upon in informed discussions and participatory decision processes. On a small level, the various departments of the water company SEDAPAL are involved in the modelling process, whilst on a wider level, a number of stakeholders (e.g. water company, government agencies, universities, NGOs) is involved in discussions of outcomes. Thus the products are twofold: a water system simulator (which is also applicable to other cities and even to other infrastructure systems) and its instantiation and application for Lima, assisting in the overall process of stakeholder involvement and participatory decision finding. In subsequent steps, the model of the entire water system of Lima will be used for an in-depth analysis of the six scenarios set up.
Contact: Dr. Manfred Schütze, Msc. Gloria Robleto; E-Mail: ifak@lima-water.de
