Name: WASTEWATER REUSE AND WATER HARVESTING FOR IRRIGATION STUDY
Approval date: 04-Oct-2011
Task Manager: EGEH Mohamud Hussein, RDGS4
Total cost: 857492.4 Currency: UAC
Source(s) of financing Government: 257492.4 MICF: 600000
Implementing Agency: MINISTRY OF AGRICULTURE
The study will be carried out in two phases comprising (A) feasibility study that includes an Environmental and Social Impact Assessment (ESIA) and (B) detailed designs and draft bid documents of the recommended and agreed project. A.Phase 1: Feasibility Study The Consultant will collect all available data relevant to the study including: existing status of the urban centres covered by the project (populations, water consumption, wastewater generation, prospects for future growth, etc.), status of the existing wastewater treatment works (current capacities, treatment processes and efficiencies, volume and quality of discharged effluents, and quality of receiving rivers and streams), availability of land in the vicinity of the treatment works (amount of land available, current usage, level of productivity and number of the people within each area, etc.), availability of water and its present utilization from the sand rivers of Shashe and Motloutse (previous hydrological and hygeological studies of these rivers, records of river flows, water quality, current levels of abstraction and usage, storage potential, etc.), availability of the suitable land for irrigation along these rivers (estimated areas, current land use, population of the areas, etc.), current status of the environment in all the project areas including impacts of the current wastewater treatment plants (to the operating staff, neighbouring communities, to the receiving rivers, etc.), impacts of the current land use in areas proposed for irrigation (land ownership, land degradation, agricultural inputs, etc.), water harvesting in sand rivers (possibilities of pollution, over extraction, etc.). The consultant will analyse available information and recommend any further field surveys, measurements and investigations required to carry out the feasibility studies. Recommendations will be made of the most cost effective additional treatment required before the wastewater can be reused for irrigation. Similarly, the different available options for treatment of wastewater bio-solids (sludges) for reuse for soil conditioning will be explored. Required land will be demarcated, most suitable crops identified and appropriate irrigation systems recommended including necessary infrastructure (power and domestic water supply, sanitation and access roads). Similarly, the most appropriate water extraction methods from the sand rivers and also irrigation systems will be proposed for the identified adjacent land. The EIA study will be carried out as a planning tool, to address and mitigate all environmental concerns of the proposed project as required for Bank's projects falling in category 1. B.Phase 2: Detailed Designs Stage The second phase of the study will be the preparation of detailed designs of the project in accordance with the conclusions and recommendations of the feasibility study. Design details including necessary calculations, process design, drawings including civil, structural and electro-mechanical will be prepared for all components of the project including wastewater and bio-solids treatment, water harvesting techniques, irrigation systems, and the necessary infrastructures. Project's main components, bills of quantities, Engineer's cost estimates and implementation schedule, design report, drawings and bid documents will be prepared in adequate details to facilitate construction of the works.
The study will identify and compile all available technical data aimed at helping Government to improve the conception of irrigation projects.This will enable the Bank to create the environment for effective investment and sustainable development of the agriculture sector. The associated irrigation projects will support sustainable agriculture infrastructure and environmental protection activities, resulting in full utilisation of the planned infrastructure and selection of suitable profitable production schemes. The project will be supported by the strong commitment of the Government to eradicate poverty and diversify the economy.
Botswana's reliance on mineral wealth has allowed it to achieve significant development although it has not been equally and widely shared. High unemployment and poverty, especially in rural areas are a challenge, with about one-third of the population living below the poverty line. Given that diamond production is likely to cease in 2030, growth in non-diamond sectors will need to accelerate significantly in order to avoid a contraction of the economy. The Government has identified agriculture, among others, as the main potential sectors for diversification. However, development of agriculture is hampered by a number of challenges mainly limitation in water resources since it is an arid and semi-arid country which receives very little rainfall thus limits the extent of rain-fed agriculture. Irrigated agriculture has still room for expansion but it has to compete with other demands, like domestic and industrial consumers, for the available limited water resources. It is in this view that the Government has undertaken to promote economic re-use of wastewater for agriculture with the aim of putting the available land within close proximity of wastewater generation under irrigation. Crop production, using irrigation, is also being expanded using fresh water extracted from sand rivers, where practicable.