TERMS OF REFERENCE AND TECHNICAL PROPOSAL FOR HYDRAULIC MODELLING OF WATER DISTRIBUTION SYSTEMS USING EPANET – Somalia/Somaliland

TERMS OF REFERENCE AND TECHNICAL PROPOSAL FOR HYDRAULIC MODELLING OF WATER DISTRIBUTION SYSTEMS USING EPANET

Background

Oxfam humanitarian interventions focus on providing WASH support through establishing water and sanitation infrastructures. The interventions are geared towards addressing water scarcity in Somalia/Somaliland through the improvement of existing community water supply schemes through rehabilitation and new construction. Over the last few years, Oxfam has been carrying major pipeline extension as well as the construction of water storage structures and water distribution points to reduce trekking distance and queuing time which has enables the pastoral community to have more time for attending to other economic opportunities and learning and development for school going, girls. Oxfam has also carried out emergency water provision in water-stressed areas during drought season and upon failures of Gu and Dayr rains through Cash for water. To enhance the efficiency of the designed water distribution system, Oxfam is proposed to carry out EPANET training to its Public Engineering team, Partners staff and Engineers from the Ministry of Water Development -Somaliland.

Overall Objective

The overall objective of the training is to provide necessary technical support to the participant to be able to understand the basics concepts related to water supply system designing and pipeline works using EPANET software. Specifically, this training aims to provide a structured introduction to the design and modeling of water distribution systems. The modeling component of the course will enable the participant to carry out step-by-step modeling through different hydraulic networks domains by use of the state-of-the-art hydraulic engine as provided by EPANET software which can be downloaded for free

Learning Objectives

Upon completion, the participant should be able to:

• Structure design and modeling of water distribution systems and provide knowledge on theoretical and practical aspects of pressure management in water distribution systems.
• Distinguish between different network configurations and supplying schemes; recognize various consumption categories and their growth patterns, including water leakage; define the relationship between the main hydraulic parameters including how to tracks and measure the flow and pressure of water in each pipe, pipe nodes/pipe junctions, pumps, valves and storage tanks or reservoirs and the concentration of a chemical species throughout the network.
• Demonstrate understanding of steady-state hydraulics by being able to select appropriate pipe diameters, indicate the optimum location of reservoirs and identify pumps capable to supply the demand as well as Equip the participant with knowledge in both theory and practical pressure loss management in water distribution systems.
• Apply the above theoretical knowledge by learning to perform computer-aided hydraulic calculations and predict the consequences of demand growth on the hydraulic performance of a particular WTD system
• Propose preliminary hydraulic design that will integrate economic aspects, choose adequate components, and judge technical solutions dealing with the network maintenance, rehabilitation, and expansion;

Training Contents

The training will cover but not limited to the following topic:

Introduction to Water Transport and Distribution:

• Main objectives and components of water distribution systems;
• Water demand categories, patterns, calculation and forecasting;
• Steady-state hydraulics of pressurized flows, single pipe calculation, branched and looped networks,  pressure-driven demand;
• Hydraulics of storage and pumps;
• Hydraulic design: choice of supply scheme, network layouts, design of pumping stations, power requirements and energy consumption;
• Engineering design: choice of pipe materials, valves and other equipment;
• Network construction: pipe laying, testing and disinfection;
• Operation & maintenance: regular & irregular supply, network cleaning and rehabilitation.

Water Loss Management and Control:

• Definition of non-revenue water and IWA terminology used in the sector;
• Components of water losses, methods of reducing and controlling real- and apparent network losses;
• Quantification of leakage in distribution systems, leak location and repair techniques, pressure management.

Proposed Training Methodology

The overall training process will be highly participatory and will be delivered virtually. The approach involves will be various techniques; the main technique will be a practical session and simulation in which participants design the water distribution network most used in Somalia/Somaliland. In general, the following methods will be subjected in the training: –

1. Presentations and discussions
2. Plenary sessions
3. Brainstorming
4. Group work

Training Deliverable

• Duration is maximum of three days with maximum of 15 participants.
• Hand out manuals and reference materials for EPANET training
• Training report as final delivery of the work with all necessary references.

Budget Breakdown

The training is expected to run for a maximum of three days and induvial consultant should send their proposed technical and financial offer based on the TOR.

Location and Venue

Due to COVID-19, facilitators are required to deliver this online.

Application Procedure

The consultant must meet the above-required qualification and experience. Interested applicants who meet the requirements should submit a detailed technical proposal, including a detailed work plan, a proposed budget for the assignment. Similar previous work conducted will be a necessary. All applications should submit on or before the deadline via SOM-Consultancies@oxfam.org by latest 21^th April 2021.