Sustainability of least cost policies for meeting Mexico City's future water demand

Abstract

Abstract. Meeting future water demand without degrading ecosystems is one important indicator of sustainable development. Using simulations, we showed that compared to existing policy, more sustainable water supply options are similar or cheaper in cost. We probabilistically forecasted the Mexico City metropolitan zone population for the year 2015 to be 23.5 million and total required water supply to be 106 m 3 s -1. We optimized existing and potential supply sources from aquifers, surface water, treatment/reuse, and efficiency/demand management by cost to meet future supply needs; the applied source supply limits determined the degree of sustainability. In two scenarios to supply 106 m 3 s -1, the business-as-usual scenario (zero sustainability ) had an average relative unit cost of 1.133; while for the most sustainable scenario (it includes reducing potential supply basins' exploitation limits by 50%), the value was 1.121. One extreme scenario to supply the forecast's 95% confidence value (124 m 3 s -1) showed little unit cost change (1.106). The simulation shows sustainable policies can be cost-effective.

Scope sensitivity in households' willingness to pay for maintained and improved water supplies in a developing world urban area: Investigating the influence of baseline supply quality and income distribution upon stated preferences in Mexico City

“…The authorities estimate that in the year 2010, an additional 18.2 m 3 /s of water will be required in the MAMC, an increase which existing sources cannot satisfy. There is a substantial literature regarding this problem [Sanchez-Diaz and Gutierrez-Ojeda, 1997;Birkle et al, 1998;GonzalezMoran et al, 1999;Downs et al, 2000; Secretaría del Medio Ambiente, 2000; Comision Nacional de Agua (CNA), 2003a]. However, these studies have focused almost exclusively upon the supply side with little attention being paid to demand and no previous assessment of WTP.…”

Integrated Assessment of the European WFD Implementation in Extremely Overexploited Aquifers Through Participatory Modelling

“…Overexploitation in California was already estimated at about 5×10 Mm 3 year −1 in the mid 1950s (Custodio 2002). In Mexico City the intensive exploitation of groundwater has caused ground subsidence of up to 7m; here, where total abstraction reaches 40 m 3 /s −1 , the ratio of groundwater use to recharge has been estimated at 1.6 (Downs et al 2000;Ortiz-Zamora and Ortega-Guerrero 2010). In Libya, groundwater (which here is virtually non-renewable) is piped from the central and southern parts of the country to the Mediterranean coastal area, 500-900 km away (Custodio 2002;Salem 2005).…”

Changing the Culture of Underdevelopment and Unsustainability

“…The water sector is arguably one of the most fundamental elements upon which to build successful, more sustainable development policy (Downs, 1998;Downs et al, 2000). Postel (1997) recognizes that responding to water scarcity requires new ethical guidelines for Figure 3 relationships.…”