space
About UNEP
space
space
United Nations Environment Programme
Division of Technology, Industry and Economics
top image
space
space space space
space
space
Newsletter and Technical Publications

Rainwater Harvesting And Utilisation

An Environmentally Sound Approach for Sustainable Urban
Water Management: An Introductory Guide for Decision-Makers


Introduction

In most urban areas, population is increasing rapidly and the issue of supplying adequate water to meet societal needs and to ensure equity in access to water is one of the most urgent and significant challenges faced by decision-makers.

With respect to the physical alternatives to fulfil sustainable management of freshwater, there are two solutions: finding alternate or additional water resources using conventional centralised approaches; or better utilising the limited amount of water resources available in a more efficient way. To date, much attention has been given to the first option and only limited attention has been given to optimising water management systems.

Among the various alternative technologies to augment freshwater resources, rainwater harvesting and utilisation is a decentralised, environmentally sound solution, which can avoid many environmental problems often caused in conventional large-scale projects using centralised approaches.

Rainwater harvesting, in its broadest sense, is a technology used for collecting and storing rainwater for human use from rooftops, land surfaces or rock catchments using simple techniques such as jars and pots as well as engineered techniques. Rainwater harvesting has been practiced for more than 4,000 years, owing to the temporal and spatial variability of rainfall. It is an important water source in many areas with significant rainfall but lacking any kind of conventional, centralised supply system. It is also a good option in areas where good quality fresh surface water or groundwater is lacking. The application of appropriate rainwater harvesting technology is important for the utilisation of rainwater as a water resource.
 

    Table of Contents

  • Major Projects
  • DEBRI Project
  • DEBRI Project
  • Iraqi Marshlands Project
  • Iraqi Marshlands Project
  • IETC's Tools
  • Environmentally Sound Technology Information System
  • ESTIS facilitates creation and management of websites on the Internet, sharing and searching of information across multiple ESTIS websites, publishing of information by non-web designers and decentralized management of content.
  • WiseWater
  • WiseWater is a spreadsheet application for projecting reductions in Water Consumption Patterns after application of Environmentally Sound Technologies. It is included as part of the publication "Every Drop Counts: Environmentally Sound Technologies for Urban and Domestic Water Use Efficiency".
  • Pamolare
  • PAMOLARE is an environmental modelling tool to forecast the changes in water quality leading to the eutrophication of Lakes and Reservoirs.
    The versatility of PAMOLARE allows for its use in decision making process as well as for training purposes.