This training manual discusses the main principles and concepts of integrated water resources management (IWRM) and addresses the question of how IWRM can help in the maintenance and restoration of freshwater ecosystems so as to sustain their goods and services. There are a wide range of possible impacts of water use sectors (ranging from agriculture, aquaculture, industry and mining, to energy and transportation as well as domestic water use) on water resources and ecosystems with possible negative feedback loops. The major impacts of water use sectors on ecosystem services and a range of possible mitigation measures are described in this manual.

Freshwater ecosystems provide a wide range of goods and services that include flood control and wastewater purification. Yet these values are seldom appreciated, much less estimated and taken into account during decision-making processes. Many of these benefits are overlooked because they have no market and no price. They are taken for granted because they are poorly understood by water managers and provided by nature for free. Undervaluing these benefits leads to misguided decision-making which in turn may jeopardize water security, impede development and increase poverty. Water managers need to understand the functioning of the water ecosystems associated with their river basins, groundwater, estuaries and wetlands, and comprehend the value of these ecosystems for their work. This training manual provides such an understanding.

Ecosystem valuation, specifically in terms of economic valuation, offers a powerful and practical range of tools to estimate the monetary value of ecosystems and their services and inform decision-making. Specific valuation tools with their strengths and limitations are also presented in this manual.

The manual provides an understanding of environmental flows, whose assessment and application are the cornerstone of integrating ecosystems’ goods and services into IWRM. Other highly relevant and practical issues related to governance and legal reform processes required to make the above-mentioned tools work and some practical tips for integrating the knowledge in this manual into day-to-day water management are also addressed.

Themba Gumbo Director, Cap-Net UNDP