Two themes are carried through this book. The first is an introduction to the concept of materials and energy balance as a tool for understanding environmental processes and solving environmental engineering problems. The second theme of the book is the concept of sustainability, and deals with topics of water conservation, sludge minimization in water treatment, land treatment of waste water, protection of ozone layer.

Following the completion of the Diagnosis and Planning, 15,000 ha equally divided between Ethiopia and Sudan were identified and studied up to feasibility level. The Feasibility studies involved advanced investigations including determination of basic engineering design for barrages, diversions, pumping stations, irrigation and drainage infrastructure, land use and cropping pattern and systems, agricultural inputs, credit and crop production, storage, transport and marketing, and economic and financial viability, environmental impact assessment and social desirability of the projects. Detail terms of reference for the next stage (detail design) of the projects have also been prepared.

The key objective of this call by Nile Basin Initiative (NBI) is to conduct economic assessment of wetland ecosystem services as an input green infrastructure planning and development for the lower Baro Wetlands: To review documents to identify study finding and recommendations from BAS and TEEB related studies in the Lower Baro wetland system,To develop a preliminary Lower Baro wetland system map and recent period land use land cover (ecosystem account) map,To conduct a preliminary assessment of the ecosystem status and valuationof ecosystem services of the Lower Baro wetland system,To present the findings of the Lower Baro wetland system preliminary ecosystem services assessment and mappingof ecosystem accounts to NBI stakeholders.