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Table 3 Relevant future scenarios, potential consequences and analysing approaches identified in the case study

From: Using the multiple scenario approach for envisioning plausible futures in long-term planning and management of the urban water pipe systems

Main scenario Most relevant scenario specifics Water distribution potential consequences Problem description Suggested analysing approaches
Climate change Frost and temperature patterns will change, including frosting and thawing cycles - Reduced reliability
- Change in failure rates
Reliability and failure rates can be impacted by temperature changes which impacts ground movement and frosting and thawing cycles. (1a) Data analysis: correlation between failures and temperature
(1b) Data analysis: correlation between failures and frost/thaw temperature ranges
(1c) Look at future climate research literature
Demographics
Population change
Increased water demand - Need to increase hydraulic capacity
- Change in water quality and reduced corrosion problems
Population growth leads to increased water needs. Will this lead to a need to upgrade the hydraulic capabilities of the water supply? Increased water demand might actually improve water quality with regards to corrosion problems. (2a) A case study of the Oslo water supply by looking at the impact of different water demands on hydraulic capacity
Population reduction and water demand reduction - Water quality problems and increased corrosion Many Norwegian systems are already operating under low flow velocities due to high capacity on networks, so this will probably not impair the situation to any noticeable level. (2b) Estimation of de population from areas from the Norwegian national statistical database. These problems should however be solved with O&M instead of increased renewal
Delivered service Public awareness - Lower risk acceptance Means a need to generally improve network condition and system performance. Risk should at the minimum be maintained. (3a) Questionnaire to municipalities to review their perception of network risk levels
(3b) A review of the public perception of risk levels related to water and wastewater systems
- Less acceptance for discoloured water Increased problems with corrosion, particles and sedimentation increase the probability of events leading to resuspension of particles in network and discolouration of the water. (3c) Data analysis of discolouration data. However, these problems are best solved with O&M techniques instead of rehabilitation (too costly)
- Less acceptance for shut down of water supply A possible increase in failures on network will cause an increase in repairs. This, together with increased public demand to water supply, will increase the expectations and demands to continual supply of water. (3d) Can be solved by techniques for repair and proactive maintenance. Increased renewal is probably not the best solution
Technologic and methodical development More efficient and higher quality renovation methods - Simplifying rehabilitation and improving lifetime expectancy of renovation methods Higher quality no-dig methods, both the materials and the procedures. Better and more effective installation procedures. (4a) What kind of technological advancements can be expected in the next 50,100 years? Interviews of Norwegian pipe producers
Higher quality pipe materials - Improving lifetime expectancy of pipes Material quality will improve in time with better raw materials and better production standards. Technical approval of pipes will probably be a standard for Norwegian water utilities. (4b) Interviews of Norwegian pipe producers on future technological advancements
Resource capacity Lack of personnel - Lag in rehabilitation Old network. Poor performance. Too little investment in renewal of pipes. We expect that there will be an increased rehabilitation need due to the demographic echo of past construction periods. (5a) Analysis of the Norwegian water network age and construction periods
Lack of expert knowledge - Poorly managed and executed rehabilitation Too few students are being educated for the water sector. Poor management leads to poor performance of the networks. (5b) Analysis of trends in educational data compared to the future need for the water utilities
Insufficient financing in renewal - Implementation of less than optimal, but low cost, solutions Implementation of less than optimal solutions will lead to poor long-term performance in increased future investment need. (5c) Calculation of future investment needs, which then should be compared to currently planned investments in rehabilitation