Activities: Environmental Flow Assessment

Tanzania's National Water Policy provides that water for maintenance of the environment will be accorded second priority in allocation, after water for basic human needs. Also, the Environmental Management Act requires Basin Water Boards to reserve water for ecosystems. But how do we know how much water the environment needs? Pioneered by Australia, South Africa and other countries struggling with allocating limited water resources, Environmental Flow Assessment (EFA) methodologies have become accepted internationally as an appropriate tool for determining the water requirements of the environment.

Tanzania has little experience and capacity in conducting such flow assessments to support the provisions of its national water policy. The World Conservation Union (IUCN), through its Water & Nature Initiative, and the Global Environment Facility (GEF) through the UNDP, have committed to support an environmental flow assessment in Pangani River Basin as a part of the Pangani River Basin Management Project.

Objectives

The Flow Assessment has two primary objectives:
To provide technical information to water managers on the water allocations necessary to maintain environmental goods and services. These technical studies will describe the social, economic and environmental implications of such allocations to the environment. The social, economic and environmental implications of various alternative water allocation scenarios will also be elaborated in order to find the optimal balance among competing uses.
To build capacity within Tanzania to implement flow assessment programs. The capacity-building component will target the relevant research communities, water managers and decision makers.

Action Plan

Tanzanian and South African specialists consulted for more than a year to design a custom flow assessment program for Pangani River Basin to both provide necessary technical information to support decision making about water resources and build capacity within Tanzania for conducting flow assessments.

The various steps in the process include:
- Describe the hydrology of the basin over time and space.
- Delineate the basin into biophysically homogeneous zones and select sites.
-Conduct a health assessment of the rivers and estuary during wet and dry seasons.
-Conduct a baseline socio-economic assessment.
-Synthesize the technical studies and develop an understanding of the ecological and economic linkages.
-Conduct additional technical studies on topics to be identified.
-Capture the relationships between water flows, and social, economic and environmental aspects and develop a tool to model these relationships.
-Use the tool to evaluate the social, economic and environmental implications of specific water allocation scenarios envisioned for Pangani Basin.
-Disseminate findings of the flow assessment and raise awareness at all levels.