Evaluation of the Performance of Rainwater Harvesting Systems for Domestic Use in Tlalpan, Mexico City

Niall Patrick Nolan,Cecilia Lartigue

doi:10.28991/cej-2017-00000080

Abstract

Rainwater harvesting (RWH) as an alternative means of providing water in domestic contexts, is viewed as an effective supply option worldwide. In Mexico City, the water situation is critical and the provision of water services to the population represents a formidable challenge for the city’s water utilities. The main objective of this study is to evaluate the potential for RWH to supply domestic properties in Tlalpan, 1 of 16 delegations in the city with one of the highest percentages of homes unconnected to the distribution network. Results show RWH can meet 88% of household water demand during the 6 month wet season, with an annual saving of 55%. Modelling a World Health Organisation minimum demand of 20 l/p/d as a means of resilience management in the event of a water crisis, 6-month and annual savings were 99% and 80% respectively. The minimum tank size to achieve wet season savings of 90% was 6m3 in two precipitation bands and tank sizes of 13,000 – 17,000L were sufficient in 3 out of 4 to prevent overspill. The report concludes RWH is a viable method of providing water in the south of the city and should be part of an integrated water management solution.

Highlights

The issue of water scarcity is a significant and increasing threat to the environment, human health, development, energy security and the global food supply
To model the potential for Rainwater harvesting (RWH) in Tlalpan where Isla Urbana has installed a number of systems, a survey of 1186 properties was carried out at the time of installation
Potential for Potable Water Savings Including Overspill During the wet months, the results showed significant overspill at these demands

Summary

Introduction

The issue of water scarcity is a significant and increasing threat to the environment, human health, development, energy security and the global food supply. Mexico City suffers from multiple and inter-related problems regarding the quality and availability of its water supply, which so far the Government has failed in addressing adequately [4, 5]. It is the capital of the country and one of the most vulnerable areas to water scarcity. The water situation is critical, with projections to 2030 indicating that the availability of water per capita in the Valley of Mexico (where the city is located) is only going to get much worse, necessitating the search for additional, sustainable sources to help redress the problem [6]

Methods

Results

Discussion

Conclusion