Guide to COST-BENEFIT ANALYSIS of investment projects - Ramiri

Cycle and phases of the projectGreat attention needs to be paid to the preparatory stages e.g. the search for new subsurface resources andtheir qualitative and quantitative assessment by means of scout borings or hydrological surveys and studiesintended to identify the best location of dams and crosspieces, their dimensioning, and so on.Moreover, it is necessary to consider the institutional and administrative aspects related to the project aswell as the expected execution and building times. Particular attention should be paid to the legal structureof the PPP projects, as this may affect the eligibility of expenditure (see below).The technical featuresThe analysis should also be completed through the identification of technical features.Identification of basic functional data- Number of inhabitants served;- Irrigated surface (hectares);- Number and type of production units served;- Water availability per capita (l/d*inhabitant) or per hectare (l/d*hectare);- Water quality data (laboratory analysis);- Number of equivalent inhabitants, flow rates and parameters of the polluting load of the water that will be treated (laboratoryanalysis) and quality constraints of the water that will be drained (defined by the law).Identification of the territorial construction data of the infrastructure:- Location of the works on the territory, shown by properly scaled topographical maps (1:10,000 or 1:5,000 for networks andplants; 1:100,000 or 1:25,000 for collection and supply works, trunk lines);- Physical connections between the structures and the (new or existing plants); it may be useful to enclose technical drawings ofa schematic kind;- Any interference and/or interconnection with the existing infrastructures of any other type (streets, railways, electrical lines,etc.).Identification of physical and characteristic data:- Total length (km), nominal diameters (mm), nominal flow rate (l/s) and differences in height (m) of suppliers or trunk lines;- Nominal filled volumes (millions of m 3 ) and height (m) of dams (location plans and sections attached hereto);- Number, length (m) and nominal flow rate (l/s) for running water taking works (attaching location plans and sections);- Number, depth (m), diameter (mm), drained flow rate (l/s) for wells fields (attaching properly scaled location plan);- Linear development (km) and characteristic diameters (mm) of aqueducts or sewers (attaching properly scaled location plan);- Capacity (m 3 ) of tanks (attaching location plans and sections);- Occupied surface (m 2 ), nominal flow rate (l/s) and difference in height (m) of any lifting apparatus (attaching location plansand sections);- Nominal flow rate (l/s), production (m 3 /g) and absorbed / consumed power (kW or Kcal/h) of purification or desalinationplants (attaching lay-out and flow pattern);- Technical features and configuration of the main structures, for example by enclosing one or several typical sections and/orsketches (sections of ducts, layouts of control rooms, etc.) and by specifying the parts that have recently been built;- Technical and constructive features of the main lifting apparatus, production or treatment plants, by enclosing functionallayouts in details;- Nominal flow rate (l/s), capacities (equivalent inhabitants), conditioning efficiency (at least on BOD, on COD, onphosphorous and nitrogen) of purification plants as well as the technical and constructive features of drain pipes (attachinglocation plans, lay-outs and flow patterns);- Number, location in the networks, types, manufacturing technology and quality of the measuring instruments (flow rates,pressures, volumes, etc.) and of the meters for users;- In the case of projects of network rehabilitation, the technical data regarding the to be rehabilitated (pipe lengths anddiameters, materials, operating pressures and flows, leakage rates, maintenance state, etc.) must be provided, which clearlydemonstrates the necessity and appropriateness of the designed intervention;- Technical and constructive features of the buildings or other service structures, by attaching location plans and sections;- Relevant technical elements, such as crossings, cave tanks, galleries, remote control plants or computerised servicemanagement plants, etc. (by attaching data and lay-outs);- Identification of the main components and materials proposed by the project, by specifying their availability (of localproduction or importation) in the investment area;- Identification of any technology that may have been proposed for the realisation of the infrastructure, by specifying itsavailability and convenience (for example from the viewpoint of maintenance);- In the case of conditioners, identification the options for the disposal of treatment mud. In the case of desalination plants,identify the options and infrastructures for the disposal of concentrated brine.97